[Federal Register Volume 68, Number 202 (Monday, October 20, 2003)]
[Rules and Regulations]
[Pages 59865-59877]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-26378]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM81; Special Conditions No. 25-ANM-84A]


Special Conditions: Extended Range Operation of Boeing Model 777 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Amended special conditions.

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SUMMARY: These special conditions amend Special Conditions No. 25-ANM-
84, applicable to Boeing Model 777 series airplanes. They revise the 
extended range operations with two-engine airplanes (referred to as 
``ETOPS'') test requirements defined in the original special 
conditions. The revisions include changing the airplane demonstration 
test requirement from a required 1000 flight cycles to a demonstration 
of capability in ETOPS flight conditions, and allowing more than one 
airplane to be used for the airplane demonstration test. In addition, 
this revision adds post-test inspection requirements for both the 
engine demonstration test and the airplane demonstration test articles.

EFFECTIVE DATE: October 8, 2003.

FOR FURTHER INFORMATION CONTACT: Steve Clark, FAA, ETOPS Project 
Manager, Seattle Aircraft Certification Office, Propulsion Branch, ANM-
140S, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, 
Washington, 98055-4056; telephone (425) 917-6496; facsimile (425) 227-
1180.

SUPPLEMENTARY INFORMATION:

Background

    Because of concerns over engine and airplane reliability, for many 
years 14 CFR 121.161 has generally prohibited operations of two-engine 
airplanes on routes including segments that are more than one hour 
flight time from a suitable airport. This regulation contains an 
exception that allows such operations when specifically authorized by 
the Administrator. These extended range operations with two-engine 
airplanes are referred to as ETOPS. Advisory Circular (AC) 120-42A 
describes a method for obtaining ETOPS authorization if an operator can 
demonstrate sufficient engine and airplane reliability. This method is 
based on a combination of various design features and operational and 
maintenance procedures. The AC states that eligibility for 120-minute 
ETOPS

[[Page 59866]]

authorization is normally based on a showing of reliable operation for 
a minimum of 250,000 engine hours of service in the world fleet. 
Eligibility for 180-minute ETOPS authorization is normally based on a 
showing of reliable operation for at least one year in 120-minute 
ETOPS. The AC also describes an option for reducing the number of hours 
of service if adequate compensating factors are identified to give a 
reasonably equivalent database.
    On May 18, 1994, the FAA issued Special Conditions No. 25-ANM-84 
for the Boeing Model 777 series airplanes (59 FR 28234). These special 
conditions define requirements for 180-minute ETOPS approval concurrent 
with basic type certification of the airplane without the service 
experience outlined in AC 120-42A that would normally be necessary. 
These special conditions define additional safety standards that the 
FAA considered necessary to establish a level of safety equivalent to 
that provided by the airworthiness standards for non-ETOPS airplanes.
    The current 777 ETOPS special conditions consist of five main 
elements needed to provide adequate compensation for the service 
experience normally required for 180-minute ETOPS eligibility described 
in AC 120-42A. No single element is considered sufficient by itself, 
but the FAA has found that the five elements combined provide an 
acceptable substitute for actual airline service experience. The five 
elements are:

    1. Design for reliability
    2. Lessons learned
    3. Test requirements
    4. Demonstrated reliability
    5. Problem tracking system
    A description of each of these five elements is contained in the 
preamble to Special Conditions No. 25-ANM-84.
    On December 13, 1999, Boeing Commercial Airplane Group applied for 
an amendment to Type Certificate No. T00001SE to include the new Model 
777-200LR and 777-300ER airplanes. The Model 777-200LR, which is a 
derivative version of the existing Model 777-200 series airplanes, has 
the following differences from the Model 777-200:
    [sbull] The wingspan is increased from 199 feet, 11 inches to 212 
feet, 7 inches.
    [sbull] Maximum intended takeoff weight is 750,000 pounds.
    [sbull] It is capable of carrying from 301 to 440 passengers.
    [sbull] It has provisions for overhead crew and attendant rest 
areas.
    [sbull] Its range capability will be up to 8,800 nautical miles 
(16,298 kilometers).
    [sbull] It has 110,100 pounds thrust GE90 engines.
    [sbull] It has a supplemental electronic tail skid.
    [sbull] It has provisions for up to 3 auxiliary fuel tanks in the 
forward area of the aft cargo bay.
    The Model 777-300ER, which is a derivative of the Model 777-300 
airplanes, has the following differences from the Model 777-300:
    [sbull] The wingspan is increased from 199 feet, 11 inches to 212 
feet, 7 inches.
    [sbull] Maximum intended takeoff weight is 750,000 pounds.
    [sbull] It is capable of carrying from 359 to 550 passengers.
    [sbull] It has provisions for overhead crew and attendant rest 
areas.
    [sbull] Its range capability will be up to 7,250 nautical miles 
(13,427 kilometers).
    [sbull] It has 115,300 pound thrust GE90 engines.
    [sbull] It has a supplemental electronic tail skid.
    [sbull] It has a semi-levered main landing gear.
    Both models are currently approved under Type Certificate No. 
T00001SE.
    For the Model 777-300ER and Model 777-200LR, Boeing has proposed 
certain changes to the ETOPS special conditions in order to take into 
account the experience from the original baseline Model 777 engine 
programs and to eliminate any unnecessary burden from the airplane 
demonstration testing required by paragraph (e)(7) of those special 
conditions.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Boeing must show that the 
Boeing Model 777 series airplanes meet the applicable provisions of the 
regulations incorporated by reference in Type Certificate No. T00001SE 
or the applicable regulations in effect on the date of application for 
the change to the type certificate. The regulations incorporated by 
reference in the type certificate are commonly referred to as the 
``original type certification basis.'' The regulations incorporated by 
reference in Type Certificate No. T00001SE for the Boeing Model 777 
series airplanes include 14 CFR part 25, as amended by Amendments 25-1 
through 25-82. The original type certification basis is listed in Type 
Certificate Data Sheet No. T00001SE.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Model 777 series airplanes because 
of a novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, Boeing Model 777 series airplanes must comply with the fuel 
vent and exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36.
    Special conditions, as defined in Sec.  11.19, are issued in 
accordance with Sec.  11.38 and become part of the type certification 
basis in accordance with Sec.  21.101.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same novel or 
unusual design feature, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, the special conditions would also apply to the 
other model.

ETOPS Certification

    All two-engine airplanes operating under 14 CFR part 121 are 
required to comply with Sec.  121.161, which states, in pertinent part, 
that ``Unless authorized by the Administrator * * * no certificate 
holder may operate two-engine airplanes * * * over a route that 
contains a point farther than one hour flying time * * * from an 
adequate airport.'' Advisory Circular (AC) 120-42A, ``Extended Range 
Operation With Two-Engine Airplanes (ETOPS),'' provides an acceptable 
means for obtaining FAA approval for two-engine airplanes to operate 
over a route that contains a point farther than one hour flying time 
from an adequate airport. The two basic objectives of this advisory 
circular are to establish that the airplane and its supporting systems 
are suitable for the extended range mission and that the maintenance 
and procedures to be employed in conducting ETOPS operations are 
adequate. This is accomplished by acquiring a substantial amount of 
service experience during non-ETOPS operation and then extensively 
evaluating this experience in the areas of systems reliability, 
maintenance tasks, and operating procedures. When it is determined that 
the appropriate reliabilities and capabilities have been achieved, the 
airplane is found eligible to be considered for use in ETOPS operation 
by an airline.
    When Boeing was developing the Model 777 series airplane, it 
proposed that the Model 777 be approved for ETOPS operation 
simultaneously with the issuance of the basic type certificate. At that 
time, procedures did not exist for a finding of this type. The proposed 
issuance of ETOPS type design approval

[[Page 59867]]

at certification would have precluded using accumulation of service 
experience, as outlined in AC 120-42A, as a means to meet ETOPS 
approval requirements. So an alternative method was devised that 
provided an adequate level of inherent airplane reliability for ETOPS. 
It is important to note that the requirements for certification of the 
airplane regarding the design's suitability for ETOPS operation, as 
described in those special conditions, relate to type certification 
approval only. Advisory Circular 120-42A contains guidance regarding 
operational and maintenance practices criteria that must be met by the 
operator before ETOPS operations can be conducted. It is incumbent upon 
the operator to apply for operational approval in accordance with 
appropriate guidance issued by the FAA for such approvals. Compliance 
with these special conditions does not constitute operational approval.
    Special Conditions No. 25-ANM-84 contained the additional safety 
standards that the Administrator considered necessary to establish a 
level of safety equivalent to that provided by the airworthiness 
standards for transport category airplanes for non-ETOPS airplanes. 
Experience with those special conditions since issuance has provided 
the FAA with additional data to justify an amendment to Special 
Conditions No. 25-ANM-84 as described in this document.

Discussion

    Boeing has requested the FAA to revise certain parts of the test 
requirements of Special Conditions No. 25-ANM-84 defined in paragraph 
(e). The FAA has concurred that some changes are justified based on an 
analysis of previous experience applying those special conditions to 
the original three engine types approved for installation on the Model 
777 airplane. The specific changes to those requirements and the 
justification for each proposed change are discussed below.

Paragraph (e)(6) Engine Demonstration Test

    The FAA has concluded from a review of in-service experience of the 
Model 777 series airplanes that the 3000-cycle engine and propulsion 
system test required by paragraph (e)(6) of Special Conditions No. 25-
ANM-84 provides an adequate opportunity to discover cyclic-related 
failure modes associated with the design, provided that an adequate 
post-test evaluation is conducted to find conditions that could result 
in an inflight shutdown, power loss, or inability to control engine 
thrust. An FAA review of the test data from the 3000-cycle tests for 
the three original engine types installed on the Model 777 series 
airplanes has shown that most of the early in-service Model 777 engine 
failure modes could have been discovered had Boeing and the engine 
manufacturers conducted a more thorough teardown inspection and 
analysis of the 3000-cycle test engine and propulsion system hardware. 
Part conditions noted in the teardown inspection reports for the three 
baseline Model 777 engine types did later occur in service, and they 
resulted in engine inflight shutdowns or airplane diversions. However, 
because the specific condition of those 3000-cycle test parts had been 
characterized as minor deviations from normal, no specific 
investigations into how they might progress in service had been 
required as a prerequisite for ETOPS approval.
    Special Conditions No. 25-ANM-84 currently do not require a post-
test teardown inspection. However, all three engine companies, in 
cooperation with Boeing, conducted post-test teardown inspections on 
the original baseline engines installed on the Model 777 series 
airplanes based on their own experience of what would constitute an 
adequate evaluation. In order to provide a consistent standard for a 
post-test evaluation of the 3000-cycle test hardware, the FAA considers 
that a change to paragraph (e)(6) to require a complete teardown 
inspection of the engine and airplane nacelle test hardware after 
completion of the test is necessary. The inspection must include an 
analysis of any abnormal conditions found. The analysis must consider 
the possible consequences of similar occurrences in service to 
determine if they might become sources of engine inflight shutdowns, 
power loss, or inability to control engine thrust. The intent of this 
change to paragraph (e)(6) is to require further design analysis to 
catch potential sources of engine inflight shutdowns or diversions.
    For similar reasons, we consider that adding a new subparagraph 
(e)(7)(v) to require a post-test external and internal visual 
inspection of the airplane demonstration test engines and propulsion 
system hardware is needed. An analysis of the inspection results must 
identify any potential sources of engine inflight shutdown. Appropriate 
corrective actions must be performed in accordance with the provisions 
of the special conditions.
    Boeing proposed to delete the word complete from the description of 
the airplane nacelle package required for the 3000-cycle test. The 
rationale for this proposed change was that without the term complete, 
it is still understood that the test is intended to be a propulsion 
system test inclusive of the engine buildup items, but some allowance 
is made for configuration differences necessary to accommodate the test 
setup. The FAA is concerned that, without this qualifier, it is not 
clear what nacelle hardware must be installed for this test. It could 
be misinterpreted in such a way that, for instance, a functioning 
thrust reverser need not be installed. Therefore, the FAA has concluded 
that the word complete must remain in the requirement. However, we 
agree with Boeing that those configuration differences associated with 
test instrumentation and test stand interfaces with the engine nacelle 
package may be excluded, and we have added that qualification to the 
requirement in order to clarify this intent.

Paragraph (e)(7) Airplane Demonstration Test

    Number of Test Airplanes: Boeing has proposed a change to paragraph 
(e)(7) to allow the use of more than one airplane to comply with the 
airplane demonstration test requirement (three test airplanes for the 
current Model 777-300ER program). Boeing's justification includes the 
argument that using multiple airplanes is an enhancement to the ETOPS 
validation program that takes into account airplane-to-airplane 
variation. The value of obtaining ETOPS data on multiple airplanes 
versus one is the increased sample size. The FAA agrees that increasing 
the number of test airplanes in the airplane demonstration test would 
provide a better evaluation of airplane-to-airplane variability. The 
limited experience obtained during the airplane demonstration test 
program is not really sufficient to evaluate end-of-life wear-out 
failure modes, so accumulating all of the time and cycles on one 
airplane is not necessary. The main program schedule benefit from using 
multiple flight test airplanes is that testing can be completed in a 
shorter period. The FAA agrees to a change to paragraph (e)(7) to 
require that one or more airplanes must complete the airplane 
demonstration test required by that paragraph.
    Capability Demonstration vs. Reliability Demonstration: The 1000-
cycle airplane demonstration test requirement was developed with the 
intent of exposing the airplane to the conditions where the greatest 
numbers of inflight shutdowns occur. Most inflight shutdowns occur 
during takeoff and climb. The failure modes associated

[[Page 59868]]

with these takeoff- and climb-related shutdowns tend to be cyclic in 
nature for a couple of reasons.\1\ For failure modes where the risk of 
failure increases with engine thrust, the takeoff portion of the flight 
is most critical. Failure modes that occur due to improper maintenance 
or engine servicing, for instance loss of engine oil due to improper 
assembly of an oil tube connection, also tend to occur early in the 
flight. A larger number of airplane flights increases the exposure to 
these types of failures. The FAA considered a cyclic test to be the 
most appropriate airplane validation test for the original Model 777 
ETOPS special conditions. However, as stated above, we now consider 
that the 3000-cycle engine and propulsion system test required by 
paragraph (e)(6) provides an adequate opportunity to discover cyclic-
related failure modes associated with the design when the test hardware 
goes through an appropriate level of post-test teardown and inspection.
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    \1\ Data provided to the Aviation Rulemaking Advisory Committee 
(ARAC) ETOPS Working Group confirm that the inflight shutdown rate 
during the takeoff flight phase is on the order of 6 to 16 times the 
fleet average inflight shutdown rate and during the climb phase is 
2.5 to 4.5 times the fleet average.
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    For inflight shutdowns where improper maintenance is a main causal 
factor, the 1000-cycle airplane demonstration test provides multiple 
opportunities for these types of failures to occur. However, the 
maintenance procedure validation program required by paragraph (d)(2) 
is intended to minimize the probability of these occurrences. The 
airplane used for the airplane demonstration test provides 
opportunities to demonstrate those maintenance tasks associated with 
the normal operation of the airplane. The FAA considers that these 
demonstrations can be accomplished in fewer than 1000 cycles.
    Although the fewest inflight shutdowns occur during cruise, this is 
the phase of flight that is most important to an ETOPS operation. 
Traditionally, the FAA and industry have avoided trying to 
differentiate between those inflight shutdowns that may occur during 
cruise from those that would only occur in a non-ETOPS environment. The 
main reason for this approach in existing ETOPS policy is that by 
correcting all causes of inflight shutdowns, the overall integrity of 
the propulsion system is assured. Since adequate cyclic exposure would 
be evaluated by an enhanced 3000-cycle engine demonstration test, as 
proposed for paragraph (e)(6) of these special conditions, the FAA has 
concluded that the airplane validation program should emphasize 
exposure to the cruise phase of flight. During the three 1000-cycle 
tests conducted for the original Model 777 engine installation 
certification programs, only 91 of the total 1000 cycles were of 
durations of two hours or more. Since the intent of paragraph (e)(7) is 
to simulate an actual airline operation, this would better be 
accomplished through longer duration flight cycles. Long duration 
flight exposure provides additional confidence in the design against 
those cruise-related failure modes that cannot be evaluated in a cyclic 
test environment. Such failure modes could include freezing of 
entrapped water condensation or binding of propulsion system 
components, neither of which would likely occur in a sea level test 
facility.
    Based on these considerations, the FAA has determined that the 
airplane demonstration test requirement should be refocused on those 
conditions that are most prevalent in an ETOPS operating environment. 
Those conditions include long flights to a variety of airports with 
broad variations of airport elevation, temperature, and humidity. It is 
also important that these flights expose the airplane to several 
enroute climbs, such as may occur with a fully loaded Model 777-300ER 
on a long-range flight, and a number of single engine diversions. As 
such, the airplane demonstration test requirement of paragraph (e)(7) 
is revised to more clearly state the objectives of the test program. 
Those objectives include demonstrations that the aircraft, its 
components, and equipment are capable of long-range operations and 
airplane diversions, including engine-inoperative diversions, and 
function properly during those operations and diversions. This change 
in focus constitutes a significant departure from the original purpose 
of the 1000-cycle airplane demonstration test requirement, as discussed 
in the preamble to Special Conditions No. 25-ANM-84.

Reliability of 777

    In order to further justify this change in philosophy for the 
airplane demonstration test requirement from being a demonstration of 
``reliability'' to a demonstration of ``capability,'' the FAA reviewed 
the original intent of Special Conditions No. 25-ANM-84, as documented 
in the preamble to those special conditions. The purpose of this review 
was to assess whether the assumptions we made in justifying the special 
conditions are still valid, or whether they should be revised based on 
ETOPS certification experience since their issuance in June 1994.
    In the preamble to Special Conditions No. 25-ANM-84, the FAA stated 
that:

existing practices to achieve airplane certification safety 
objectives have involved definition of performance requirements, 
incorporation of safety margins, and prediction of failure 
probabilities through analysis and test. However, historical 
evidence, in general, indicates that a period of actual revenue 
service experience is necessary to identify and resolve problems not 
observed during the normal certification process. Successful 
achievement of this experience has been a prerequisite for granting 
ETOPS type design approval for a specific airplane engine 
combination. However, several recent airplane engine combinations 
incorporating new or substantially modified propulsion systems have 
demonstrated a high level of reliability consistent with ETOPS 
operation upon entry into revenue service. In addition, this high 
level of reliability was demonstrated by the small number of 
problems encountered during basic certification activity. Based on 
these successful airplane and engine development and certification 
programs, the special conditions were designed to ``result in a 
level of airplane reliability that is equivalent to the level of 
reliability previously found to be acceptable based upon service 
experience.''

    The basic premise behind the engine and airplane demonstration 
tests required by paragraphs (e)(6) and (e)(7) of the original special 
conditions was that those tests would provide a final validation of an 
``inherent'' level of reliability that was the product of an enhanced 
design and test process. This is similar to the purpose of the function 
and reliability testing required by Sec.  21.35(b)(2). The FAA's 
expectation for these tests was that no significant failures would 
occur. The probability of significant design failures occurring on a 
one-airplane flight test is so low that if any do occur, that would be 
indicative of a design that is not suitable for ETOPS approval. This 
expectation is contained in the ``type and frequency'' requirement of 
special conditions paragraph (h)(1). Statistical reliability studies 
have shown that a much larger database would be required to validate a 
design's true reliability with a significant degree of confidence.
    No major engine failures occurred during the 1000-cycle airplane 
demonstration tests for any of the three engine types certified on the 
Model 777 series airplane, although several engine design problems were 
discovered during other certification testing that affected the start 
and conduct of those tests. The Reliability Assessment Board (RAB) 
evaluated each of these design problems in compliance with paragraph 
(g) of the special conditions, and found the Model

[[Page 59869]]

777 to be suitable for ETOPS type design approval with the 
incorporation of corrective actions identified in Appendix 1 of the RAB 
final recommendation reports for the three engine types. There were 
hardware similarities between engines with the original certified 
thrust ratings and follow-on higher-thrust-rated engines, and the FAA 
certified each of those follow-on engine derivatives for ETOPS in 
consideration of those hardware similarities. The FAA accepted the 
original baseline engine test programs as showing compliance with the 
3000-cycle propulsion system ground test and 1000-cycle airplane 
demonstration test requirements for the follow-on derivative engines. 
Although the 3000-cycle and 1000-cycle tests were not repeated for 
those follow-on derivative engines, Boeing and the engine companies 
completed reduced ground and flight test demonstrations tailored to the 
design changes being introduced in compliance with the Test Features 
requirement of special conditions paragraph (c)(4). Therefore, the 
follow-on engine derivatives are not included in this analysis of the 
1000-cycle airplane demonstration test requirement.
    The Boeing Model 777-200 series airplane powered by Pratt & Whitney 
PW4077 engines was approved for ETOPS on May 30, 1995 and entered 
service in June 1995. By all accounts, it was a very successful new 
model introduction. This was followed by ETOPS approval of the Model 
777-200 series airplanes powered by General Electric GE90-77B and 
Rolls-Royce RB211-Trent 877-17 engines in October 1996. The inflight 
shutdown (IFSD) rate for all three engine types was zero for at least 
the first year in service. The Pratt & Whitney PW4000 series engines 
reached a peak 12-month rolling average engine IFSD rate of .018/1000 
hours in October 1996. The General Electric GE90 series engines reached 
a peak of .021 for one month in July 1998 and the Rolls-Royce Trent 
series engines reached a peak of .016 in December 1997. Although the 
inflight shutdown rates stayed within the allowable .02/1000 hour 
standard for 180-minute ETOPS, significant design problems were 
discovered on each engine type after ETOPS approval.
    During the first two years after ETOPS approval of each engine type 
on the Model 777 series airplanes, the FAA was concerned that the 
design problems being discovered may have indicated a failure of the 
early ETOPS process to identify those failure modes before they 
occurred in service. Some failure modes had the potential to result in 
inflight shutdowns had they occurred under different circumstances or 
had they not been detected during maintenance for unassociated reasons. 
A summary of the actual problem reports for these inflight shutdowns 
and other events, which were submitted in compliance with paragraph (f) 
of these special conditions, is contained in Table 1. Had every one of 
those events resulted in an engine inflight shutdown, the resulting 
IFSD rates for each engine type would have been significantly higher. 
Boeing, the engine manufacturers, the FAA, and other regulatory 
authorities worked together to prevent additional inflight occurrences 
of these failure types. The actual inflight shutdown rates prove that 
these early in-service problems were successfully managed to maintain 
the safety of 777 ETOPS operations worldwide.

                                                     Table 1
----------------------------------------------------------------------------------------------------------------
      Date occurred        EE-1      Engine type        Affected system          Event description
----------------------------------------------------------------------------------------------------------------
10/1/1995...............  101               PW               ENGINE--OIL PUMP......  Airplane diversion due to
                                                                                      low oil quantity. Engine
                                                                                      not shut down, but oil
                                                                                      quantity indication went
                                                                                      to zero. Related to LP01
                                                                                      problem.
5/19/1996...............  179               PW               ENGINE................  Takeoff aborted due to EGT
                                                                                      exceedance. A loose B-nut
                                                                                      was found on the PS3 line
                                                                                      to the 2.95 bleed valve,
                                                                                      which caused erratic
                                                                                      operation.
5/30/1996...............  181               PW               ENGINE................  Air turnback due to high
                                                                                      oil consumption. Oil
                                                                                      wetness noted and
                                                                                      corrected from previous
                                                                                      flights. Consumption
                                                                                      continued to be high.
8/24/1996...............  233               PW               ENGINE................  IFSD--Inflight shutdown due
                                                                                      to low oil pressure
                                                                                      indication. Plastic
                                                                                      shipping cap was left in
                                                                                      the LPO1 oil line during
                                                                                      installation as part of
                                                                                      fleet upgrade.
10/5/1996...............  254               PW               ENGINE................  IFSD--Engine was shut down
                                                                                      due to low oil quantity
                                                                                      and low oil pressure.
                                                                                      Loose main oil line at
                                                                                      filter housing. Repeat of
                                                                                      oil line shipping cap
                                                                                      problem.
10/11/1996..............  261               PW               ENGINE................  Air turnback. Engine
                                                                                      experienced high vibration
                                                                                      during cruise. Vibration
                                                                                      indication exceeded EICAS
                                                                                      ``Pop-up'' level at 4.06.
3/26/1997...............  385               PW               ENGINE................  Twelve quarts of oil lost
                                                                                      after a series of training
                                                                                      flights due to a leak of
                                                                                      an oil line to the fuel/
                                                                                      oil cooler. Oil loss took
                                                                                      place over approximately 3
                                                                                      hours of flight time.
2/24/1997...............  G-65              GE               ENGINE GEARBOX........  Air turnback due to loss of
                                                                                      right backup generator
                                                                                      followed by engine oil
                                                                                      filter EICAS message. Root
                                                                                      cause was a failed gearbox
                                                                                      backup generator pad
                                                                                      bearing.
11/4/1997...............  G-84              GE               ENGINE................  IFSD--Engine experienced a
                                                                                      power loss during
                                                                                      approach. A restart
                                                                                      attempt was unsuccessful.
                                                                                      Root cause was a sticking
                                                                                      bypass valve in the
                                                                                      hydromechanical unit
                                                                                      (HMU).
11/9/1997...............  G-87              GE               ENGINE................  Flight crew heard a surge
                                                                                      toward the end of the
                                                                                      takeoff roll and tower
                                                                                      reported seeing flames
                                                                                      from the engine. At 600
                                                                                      feet, the engine surged
                                                                                      again. The flight crew
                                                                                      reduced power and returned
                                                                                      to the airport.
3/12/1998...............  G-96              GE               ENGINE................  Pilot heard a bang and a
                                                                                      tower reported fire from
                                                                                      the tailpipe after power
                                                                                      was set for takeoff. The
                                                                                      takeoff was aborted. Metal
                                                                                      was found in the tailpipe.
6/22/1998...............  G-108             GE               ENGINE................  IFSD--After takeoff, the
                                                                                      pilot received low oil
                                                                                      pressure and low oil
                                                                                      quantity indications. The
                                                                                      pilot shut down the
                                                                                      engine. Two of four oil
                                                                                      filter cover bolts were
                                                                                      loose due to inserts
                                                                                      pulling out of the filter
                                                                                      housing casting.

[[Page 59870]]

 
7/1/1998................  G-110             GE               ENGINE................  IFSD--Uncommanded engine
                                                                                      inflight shutdown during
                                                                                      cruise at flight level
                                                                                      370. Flight crew noted a
                                                                                      rapid loss of oil pressure
                                                                                      and N2. Root cause was a
                                                                                      Number 3 bearing failure.
7/22/1998...............  G-112             GE               ENGINE................  IFSD--During cruise, EICAS
                                                                                      indication of low oil
                                                                                      quantity. Pilot shut down
                                                                                      the engine. Oil filter
                                                                                      housing cover bolts were
                                                                                      over-torqued resulting in
                                                                                      stripped threads in the
                                                                                      oil filter housing
                                                                                      inserts.
11/20/1998..............  G-120             GE               IDG Installation......  IFSD--Crew started return
                                                                                      to departure airport due
                                                                                      to indication of complete
                                                                                      oil loss. Engine was
                                                                                      subsequently shut down
                                                                                      when oil pressure dropped
                                                                                      to 10 psi. The integrated
                                                                                      drive generator (IDG)
                                                                                      packing was damaged during
                                                                                      installation.
10/11/1996..............  R-63              RR               ENGINE--RADIAL DRIVE    Flight diverted after crew
                                                              SHROUD.                 observed right engine oil
                                                                                      quantity loss approx. 5
                                                                                      hours into flight. Found
                                                                                      cracked upper radial drive
                                                                                      shroud.
10/11/1996..............  R-64              RR               ENGINE--FUEL NOZZLE...  Fuel found leaking from
                                                                                      Zone 2 during
                                                                                      investigation of R-63 oil
                                                                                      loss. Source of fuel leak
                                                                                      was a cracked weld on the
                                                                                      No. 24 fuel nozzle (top
                                                                                      dead center).
10/25/1996..............  R-65              RR               ENGINE--RADIAL DRIVE    After engine shutdown at
                                                              SHROUD.                 the gate, the right engine
                                                                                      oil quantity indicated 9
                                                                                      qts. Upper radial drive
                                                                                      shroud found cracked.
11/12/1996..............  R-67              RR               ENGINE................   ``ENGINE OIL PRESS R''
                                                                                      EICAS message displayed
                                                                                      after landing. Engine shut
                                                                                      down. Oil pump drive shaft
                                                                                      found sheared.
1/26/1997...............  R-91              RR               ENGINE--STEP ASIDE      Low oil quantity caused by
                                                              GEARBOX.                crack in step aside
                                                                                      gearbox housing
                                                                                      approximately 4 to 5
                                                                                      inches long.
5/24/1997...............  R-109             RR               ENGINE................  Engine was shut down on
                                                                                      takeoff following high
                                                                                      power surge. Subsequent
                                                                                      borescope inspection
                                                                                      revealed HPC rotor 1 blade
                                                                                      failure caused by foreign
                                                                                      object damage that was
                                                                                      consistent with blade
                                                                                      damage noted on 5/20/97
                                                                                      inspection.
7/7/1997................  R-112             RR               ENGINE................  Aircraft diversion caused
                                                                                      by excessive oil leakage
                                                                                      due to incorrectly
                                                                                      installed lower bevel box
                                                                                      O-ring seal following
                                                                                      radial drive shaft
                                                                                      replacement.
7/26/1997...............  ................  RR               ENGINE................  Aircraft diversion due to
                                                                                      high oil consumption. Not
                                                                                      related to step aside
                                                                                      gearbox housing cracking
                                                                                      problem.
9/16/1997...............  R-113             RR               ENGINE................  IFSD--Engine shutdown at
                                                                                      400 feet after takeoff due
                                                                                      to high-pressure
                                                                                      compressor failure.
----------------------------------------------------------------------------------------------------------------

Reliability of 737 Next Generation (737NG)

    As part of the process of reviewing existing methods for ETOPS 
approval, the FAA also analyzed data from the initial in-service period 
for Boeing Model 737-600, 737-700, and 737-800 airplanes powered by 
CFM56-7 engines. As a group, these variants of the Model 737 were 
referred to as the 737 Next Generation, or ``737NG.'' Even though early 
ETOPS special conditions were not issued, the 737NG was chosen for this 
analysis because it followed an ETOPS approval process program that was 
very similar to what Boeing is proposing for the Model 777-300ER 
airplane. Several months after entry into service, however, the 737NG 
did not exhibit an acceptable level of propulsion system reliability 
for ETOPS approval. Early ETOPS special conditions were intended to 
identify a design not suitable for ETOPS approval prior to type 
certification.
    Boeing proposed in 1994, prior to the Model 777's type 
certification, that the 737NG be certified as an early ETOPS airplane 
in a manner similar to the Model 777, but without all of the testing 
required in the Model 777 special conditions. Since the success of the 
Model 777 program was still an unknown at the time of Boeing's request 
for the 737NG, the FAA did not agree to Boeing's proposed changes to 
the airplane demonstration test requirement. Early ETOPS special 
conditions for the 737NG were never issued. Even so, Boeing proceeded 
with those elements of the Model 777 special conditions that the 
company had proposed to accomplish. These included the relevant 
experience assessment, design requirements assessment, 3000-cycle 
propulsion system ground test, and enhanced problem reporting and 
resolution.
    Although the FAA never issued special conditions for the 737NG 
program, we agreed that the elements from the Model 777 special 
conditions that Boeing did accomplish justified a reduction in the 
service experience normally required for ETOPS type design approval, as 
outlined in AC 120-42A. Boeing presented the following information in 
support of its request for a reduction in service experience required 
for ETOPS certification.
    [sbull] ``Design involved lessons learned, similar to 777 Early 
ETOPS process.
    [sbull] ``APU most thoroughly tested in Allied Signal history--more 
than 3000-cycle ground test, including hot/cold exposure.
    [sbull] ``Propulsion system subjected to 3000-cycle ground test, 
intentionally unbalanced, with three 180-minute diversion cycles.
    [sbull] ``Flight testing included a Southwest Airlines 50-cycle 
demonstration, using airline crews and maintenance. During the Function 
and Reliability testing, 61 ETOPS cycles were conducted with three 
single engine 180-minute diversions.
    [sbull] ``A proposed ETOPS problem tracking and resolution system, 
similar to that used on the 777 that will remain in effect until the 
fleet attains 250,000 engine fleet hours.''
    In its analysis of the 737NG approval process, the FAA noted that 
these program elements, at the time, had been accomplished with good 
results. The engines and airplane system had performed well during the 
test programs, with results comparable to the Model 777 test fleet (all 
engines). The in-service 737NG airplanes had achieved a 98.96% dispatch 
reliability rate after 45 days in service, better than any previous 
Boeing airplane. Boeing's

[[Page 59871]]

proposal included an accumulation of 15,000 fleet engine hours of 
service experience before requesting ETOPS approval. At that time, 
there would be three airplanes with more than 1000 flight cycles, the 
total 737NG fleet would have accumulated more than 20,000 flight 
cycles, and the high-time airplane/engines would have more than 2000 
flight cycles. During the 737NG approval process, the FAA concurred 
with Boeing's proposal to require 15,000 hours of service experience 
based on the following:
    [sbull] ``The FAA has agreed to the concept that ETOPS at entry 
into service can be achieved by appropriate design and testing as 
evidenced by the 777 special conditions, which have now been validated 
through actual service experience,
    [sbull] ``The 737NG/CFM56-7B airframe/engine configuration is a 
derivative/evolution of the existing 737-300/400/500 which through 
extensive service experience has demonstrated exceptional reliability, 
and, is approved for 120-minute ETOPS,
    [sbull] ``Except for the lack of a dedicated 1000-cycle ETOPS test 
program, design and testing of the 737NG/CFM56-7B mirrors what was done 
on the 777 to satisfy Early-ETOPS approval,
    [sbull] ``The additional 15,000 engine hour in-service evaluation 
plus the fact that three 180-minute single engine diversions were 
performed during Function and Reliability testing more than compensates 
for the omission of a 1000-cycle test,
    [sbull] ``The satisfactory performance of the 737NG/CFM56-7B 
airframe/engine configuration during the certification testing, and
    [sbull] ``The proven ability of Boeing to satisfactorily manage 
ETOPS airworthiness of the 777 fleet in the face of problems 
encountered in service. The 737NG proposal includes a problem tracking 
and resolution system that will remain in effect for a full 250,000 
engine hours.''
    The Model 737-700 was the first variant of the 737NG to enter 
service, in December 1997. Section 4.2 of the FAA-approved 120-minute 
ETOPS Airplane Assessment Report for the Model 737-700, Boeing Document 
Number D033A003, Revision B, states that the Model 737-700 was 
designed, manufactured, and tested for extended range operations at 
entry into service. The following additional supporting statements were 
also made.

    a. ``The 737-700 airplanes have been designed and manufactured 
based on regimented application of lessons learned from other ETOPS 
program experience as well as the in-service experience of earlier 
737 models.
    b. ``The 737-700 airplane was subjected to a rigorous test 
program as described in following paragraphs. Production equivalent 
equipment where appropriate, was used to support test objectives. 
Equipment was production equivalent as defined at the time of the 
test.''

    No significant propulsion system design problems occurred during 
any of the testing described above. Two inflight shutdowns did occur 
during certification flight testing. One was caused by an indication 
fault within the electronic engine control that was corrected with a 
simple software change. The other was caused by an inappropriate flight 
test condition.
    Boeing stated in the Model 737-700's 120-minute ETOPS Airplane 
Assessment Report that the fleet reached the 15,000-hour mark during 
the month of April 1998. At that time, there had been no inflight 
shutdowns in service. However, on May 9, 1998, before the FAA had 
completed its assessment of the airplane for ETOPS approval, the first 
inflight shutdown occurred. A second inflight shutdown occurred during 
the month of May, and the fleet exceeded the accepted 120-minute ETOPS 
standard of .05 inflight shutdowns per 1000 engine hours. Three 
inflight shutdowns occurred in June 1998, and one in July 1998. The 
peak inflight shutdown rate during this period was .085/1000 hours at 
the end of June 1998, which clearly did not meet the minimum standard 
for ETOPS type design approval.
    The six engine inflight shutdowns were caused by three different 
failure root causes. Boeing and CFMI, the engine manufacturer, 
undertook aggressive actions to correct each of these design problems 
as they occurred. The high rate of fleet hourly accumulation during 
this period, however, resulted in new ETOPS reportable events occurring 
faster than the known problems could be corrected. This delayed FAA 
consideration of the Model 737-700 for ETOPS approval until the 
problems were brought under control. A consequence of the high rate of 
fleet hourly accumulation was that, with no additional inflight 
shutdowns, the inflight shutdown rate decreased rapidly and was within 
the ETOPS type design approval standard by the end of 1998. The FAA 
approved the Model 737-600/-700/-800 (737NG) for 120-minute ETOPS 
approximately one year after entry into service with over 300,000 
engine-hours of service experience and an inflight shutdown rate of 
.020/1000 hours.

Conclusions From Comparison of Model 777 and 737NG

    In comparing the 737NG experience with that of the Model 777, the 
FAA observes that there is a fleet hourly accumulation rate above which 
aggressive problem management to qualify for early ETOPS certification 
may become resource prohibitive. Therefore, when certifying an 
airplane/engine combination that will be entering service with a high 
production rate resulting in a rapid accumulation of engine hours, 
manufacturers may find it more cost-effective to use the service 
experience criteria of AC 120-42A than to follow the rigorous 
requirements of the early ETOPS process.
    As stated earlier, the Model 777 ETOPS special conditions were 
designed to ``result in a level of airplane reliability that is 
equivalent to the level of reliability previously found to be 
acceptable based upon service experience.'' As previously noted, the 
current Model 777 ETOPS special conditions consist of five main 
elements needed to provide adequate compensation for the service 
experience normally required for 180-minute ETOPS eligibility described 
in AC 120-42A. No single element is considered sufficient by itself, 
but the FAA has found that the five elements combined provide an 
acceptable substitute for actual airline service experience. The five 
elements are:
    1. Design for reliability.
    2. Lessons learned.
    3. Test requirements.
    4. Demonstrated reliability.
    5. Problem tracking system.
    Even though the overall objective is a level of airplane and 
propulsion system reliability that is equivalent to that achieved 
through service experience, we considered the uncertainty of actually 
achieving that goal in the development of these special conditions. The 
first three elements focus on designing an airplane to eliminate 
sources of engine inflight shutdowns and diversions to the greatest 
practical extent. This is accomplished by an overall design philosophy 
to preclude sources of engine inflight shutdowns and diversions using 
the manufacturer's experience with earlier designs to identify 
successful and unsuccessful design features. The additional testing 
required by the special conditions focuses on exposing the design to 
conditions that in the past have contributed to engine failures, such 
as high engine vibration or repeated exposure to humid and inclement 
weather on the ground followed by long-range operation at the extreme 
cold

[[Page 59872]]

temperatures at high altitude. These design and test elements do not 
assure a level of reliability that is equivalent to that based on 
service experience. Instead, they result in an acceptable level of 
inherent design reliability from which we can successfully manage ETOPS 
fleet safety once the airplane enters service.
    The fourth element, ``demonstrated reliability,'' provides the FAA 
with a standard by which to judge a design against existing ETOPS-
approved airplanes. This gives the FAA a standard from which to 
withhold ETOPS approval from airplanes that experience significant 
failures during certification testing, demonstrating that they are not 
suitable for ETOPS. However, it does not by itself guarantee that 
designs showing no significant failures during flight testing will have 
adequate reliability for ETOPS.
    To manage fleet safety after ETOPS approval, we rely on the fifth 
element of the ETOPS special conditions. Paragraph (f) of the special 
conditions requires a problem tracking system for the prompt 
identification of those problems that could impact ETOPS safety. The 
FAA uses this enhanced problem reporting system to work with the 
airplane and engine manufacturers to aggressively manage and correct 
significant design problems identified after ETOPS approval. This 
requirement is the ``catch-all'' for those design flaws that are not 
caught by the other elements of the special conditions during airplane 
design and testing.
    The first in-service inflight shutdown of the Model 737-700 variant 
of the 737NG did not occur until the fleet had accumulated 
approximately 30,000 engine-hours. The FAA could not have expected that 
a complete 1000-cycle airplane demonstration test would have had a 
better chance of discovering the types of problems that occurred in 
service on the 737NG than the nearly 30,000 hours accumulated on 
multiple airplanes and engines prior to the first inflight engine 
shutdown. While significant propulsion system failures occurring during 
type certification testing, including the additional testing required 
by the ETOPS special conditions, may indicate that a design is not yet 
ready to enter ETOPS service, the 737NG experience shows that the 
reverse cannot be stated with a significant degree of confidence. A 
lack of significant failures during certification testing does not in 
itself assure an ETOPS-suitable design at entry into service.
    The Model 777 experience shows that a relatively small fleet can be 
managed successfully during the initial service period based on the 
data provided by the enhanced problem tracking system required by 
special conditions paragraph (f). The 737NG experience shows that a 
larger fleet may require a much more resource-intensive fleet 
management program. However, had the 737NG received its ETOPS approval 
as originally proposed prior to its first inflight shutdown in service, 
the problem reporting system that Boeing had in place gave the FAA 
timely identification of the problems causing inflight shutdowns so 
that we could have required appropriate corrective action through the 
airworthiness directive process to maintain ETOPS safety. Such 
airworthiness directives could have required the operators to 
incorporate design changes prior to further ETOPS flight or withdrawn 
ETOPS approval.
    Although we cannot be certain that an airplane approved for ETOPS 
under the special conditions will have the same maturity at original 
type certification as an airplane that we have approved based on 
service experience, our experience with the Model 777 and the 737NG 
confirms that the five elements of the special conditions, in 
conjunction with the FAA's normal safety oversight processes, 
adequately compensate for that uncertainty.
    The changes to the engine demonstration test and the airplane 
demonstration test include enhanced post-test inspection requirements 
and are intended to address our experience with the original ETOPS 
special conditions, which identified several shortcomings in the 
original test requirements. These changes are needed to more clearly 
focus the testing on the objective of exposing the engines and airplane 
to those operating conditions that give us the best chance of 
identifying underlying major design flaws that could jeopardize ETOPS 
safety in service. These changes provide a better evaluation of the 
design than the existing requirements, including the 1000-cycle 
airplane flight test as previously conducted.
    The FAA therefore is changing the purpose of the airplane 
demonstration test requirement of paragraph (e)(7) from a demonstration 
of reliability to a demonstration of airplane capability under the 
types of ETOPS operational and diversion scenarios discussed in this 
document. The requirements of that airplane demonstration test have 
been changed accordingly.

Aged Engine Requirement

    In response to Boeing's request, the FAA is deleting paragraph 
(e)(7)(ii), which currently requires the installation of the engine and 
propulsion system from the 3000-cycle engine demonstration test 
required by paragraph (e)(6), or another suitable aged engine, on the 
1000-cycle demonstration test airplane for a minimum of 500 cycles. 
Boeing provided the following information in support of its request for 
deleting the aged engine requirement.
    Review of the aged engine data from the baseline Model 777 program 
showed that the nature of the findings, which occurred on the aged 
engines, was not related to the aging of the engines. Instead, the 
findings were related to the variation that occurs during 
manufacturing, assembly, etc. This lesson learned on the aged engines 
is consistent for each engine manufacturer's baseline Model 777 ETOPS 
test program.
    The lack of findings related to the aging of an engine in the ETOPS 
flight test program has been demonstrated three times. Based on this 
consistent demonstration, there is no further need to maintain the 
requirement for an aged engine in the flight test program. 
Additionally, flying more airplane/engine combinations will provide 
increased opportunities for evaluating potential problem areas.
    Boeing reported nine events (EE-1 Reports) which occurred during 
the aged engine portions of the 1000-cycle tests for the three baseline 
engine types, with an explanation of why the aged engine requirement 
was not necessary in order to identify each failure. Boeing stated that 
the lack of any EE-1 reports from the post-test inspections is an 
indication that there were no significant findings from the aged engine 
testing.

FAA Analysis of Boeing's Proposal

    The original intent of the aged engine requirement was to expose 
the 3000-cycle test engine, or equivalent, to inflight conditions that 
cannot be simulated in a ground test environment. This would further 
validate the propulsion system design out to an age beyond 3000 cycles. 
Boeing data available at the time the ETOPS special conditions were 
developed indicated that 95% of all new significant failure modes occur 
on airplane propulsion systems with 3000 cycles or less. That concept 
is still valid. The lack of specific findings on the aged engine during 
the 1000-cycle airplane validation test only confirms the validity of 
the Reliability Assessment Board's conclusion that those baseline Model 
777 engine installations were suitable for 180-minute ETOPS. A number 
of significant events during the

[[Page 59873]]

1000-cycle test program would have jeopardized that conclusion.
    The question that the FAA considers to be more relevant is whether 
or not a greater benefit would come from a more thorough teardown 
inspection and analysis of the 3000-cycle test engine and propulsion 
system hardware than from this additional level of validation. In this 
regard, the FAA agrees with Boeing that other test articles may provide 
sufficient experience to uncover the majority of age-related problems 
independent of the additional exposure provided by the 1000-cycle test 
inflight exposure.
    In consideration of the need to perform a detailed analysis of the 
3000-cycle test engine and the extra expense of using a parallel 3000-
cycle test engine as ``another suitable aged engine,'' the FAA agrees 
that the requirement for installation of an aged engine on the ETOPS 
test airplane can be eliminated provided significantly improved 
processes are used to analyze the condition of the 3000-cycle test and 
airplane demonstration test engines at the conclusion of these tests, 
as reflected in the revised paragraphs (e)(6) and (e)(7).

Miscellaneous Revisions

    We are also incorporating the following revisions to the special 
conditions.
    Re-identification of paragraph (e)(7)(iii) as (e)(7)(iv) and 
revision of the requirement that the 1000-cycle test airplane be 
operated and maintained using the recommended operations and 
maintenance procedures to recognize that more than one test airplane 
may be used.
    Replacement of the reference to the ``1000-cycle ETOPS test'' with 
``Airplane Demonstration Test'' in paragraph (g)(2) in order to be 
consistent with the changes to paragraph (e)(7).
    Replacement of the reference to the ``1000-flight-cycle ETOPS 
test'' with ``Airplane Demonstration Test'' in paragraph (h)(1) in 
order to be consistent with the changes to paragraph (e)(7).

Discussion of Comments

    Notice of Proposed Special Conditions No. 25-03-04-SC for the 
Boeing Model 777 series airplanes was published in the Federal Register 
on June 13, 2003 (68 FR 35335), with a correction to the original 
publication issued on June 23, 2003 (68 FR 37205). Four comments were 
received, and all of them concur with the special conditions as 
proposed. Therefore, the special conditions are adopted as proposed.

Special Conditions Revisions

    For clarity, the revised sections of the original Special 
Conditions No. 25-ANM-84 are printed below. The final special 
conditions are printed in their entirety, with revisions incorporated, 
at the end of this document. Portions of the special conditions that 
remain unchanged are discussed in the preamble to the original Special 
Conditions No. 25-ANM-84 (59 FR 28234).

Revisions to Special Conditions No. 25-ANM-84

    (e)(6) Engine Demonstration Test. One engine of each type to be 
certificated with the airplane must complete 3000 equivalent airplane 
operational cycles. The engine must be configured with a complete 
airplane nacelle package for this demonstration, including engine-
mounted equipment except for any configuration differences necessary to 
accommodate test instrumentation and test stand interfaces with the 
engine nacelle package. At completion of the engine demonstration test, 
the engine and airplane nacelle test hardware must undergo a complete 
teardown inspection. This inspection must be conducted in a manner to 
identify abnormal conditions that could become potential sources of 
engine inflight shutdown. An analysis of any abnormal conditions found 
must consider the possible consequences of similar occurrences in 
service to determine if they may become sources of engine inflight 
shutdowns, power loss, or inability to control engine thrust. Any 
potential sources of engine inflight shutdown identified must be 
corrected in accordance with paragraph (g)(2).
    (e)(7) Airplane Demonstration Test. In addition to the function and 
reliability testing required by 14 CFR 21.35(b)(2), for each engine 
type to be certificated with the airplane, one or more airplanes must 
complete flight testing which demonstrates that the aircraft, its 
components, and equipment, are capable of and function properly during 
long range operations and airplane diversions, including engine-
inoperative diversions.
    (i) The flight conditions must expose the airplane to 
representative operational variations based on the airplane's system 
and equipment design and the intended use of the airplane including:
    (A) Engine inoperative maximum length diversions to demonstrate the 
airplane and propulsion system's capability to safely conduct a 
diversion.
    (B) Non-normal conditions to demonstrate the airplane's capability 
to safely divert under worst case probable system failure conditions.
    (C) Simulated airline operations including normal cruise altitudes, 
step climbs, and maximum expected flight durations out of and into a 
variety of departure and arrival airports.
    (D) Diversions to worldwide airports representative of those 
intended as operational alternates.
    (E) Repeated exposure to humid and inclement weather on the ground 
followed by long-range operation at normal cruise altitude.
    (ii) The flight testing must validate expected airplane flying 
qualities and performance considering engine failure, electrical power 
losses, etc. The testing must demonstrate the adequacy of remaining 
airplane systems and performance and flightcrew ability to deal with an 
emergency considering remaining flight deck information following 
expected failure conditions.
    (iii) The engine-inoperative diversions must be evenly distributed 
among the number of engines in the applicant's flight test program.
    (iv) The test airplane(s) must be operated and maintained using the 
recommended operations and maintenance manual procedures during the 
airplane demonstration test.
    (v) At completion of the airplane demonstration test, the test 
engines and engine-mounted equipment must undergo a complete external 
on-wing visual inspection. The engines must also undergo a complete 
internal visual inspection. These inspections must be conducted in a 
manner to identify abnormal conditions that could become potential 
sources of engine inflight shutdowns. An analysis of any abnormal 
conditions found must consider the possible consequences of similar 
occurrences in service to determine if they may become sources of 
engine inflight shutdowns. Any potential sources of engine inflight 
shutdown that are identified must be corrected in accordance with 
paragraph (g)(2).
    (g)(2) The FAA Reliability Assessment Board will review and 
evaluate the data from the problem tracking and resolution system to 
establish compliance with the requirements of paragraph (h). The board 
will evaluate the overall type design for ETOPS suitability as 
demonstrated in flight test, and the Airplane Demonstration Test,
    (h)(1) For the engine and airplane systems, the type and frequency 
of failures that occur during the airplane flight test program and the 
Airplane Demonstration Test must be consistent with the type and 
frequency of failures or malfunctions that would be expected

[[Page 59874]]

to occur on presently certified 180-minute ETOPS airplanes. The 
failures to be considered are those associated with system components 
that conform to the type design requested for certification. The 
Reliability Assessment Board will determine compliance with this 
requirement based on an evaluation of the problem reporting system 
data, considering system redundancies, failure significance, problem 
resolution, and engineering judgment.

Applicability

    As discussed above, these special conditions are applicable to 
Boeing Model 777 series airplanes. Should The Boeing Company apply at a 
later date for a change to the type certificate to include another 
model incorporating the same novel or unusual design feature, the 
special conditions would apply to that model as well.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, as flight testing addressed by the changes 
incorporated into these final special conditions is imminent for the 
Boeing Model 777-200LR and 777-300ER series airplanes, the FAA finds 
that good cause exists to make these special conditions effective upon 
issuance.

Conclusion

    This action affects only certain novel or unusual design features 
on Boeing Model 777 series airplanes. It is not a rule of general 
applicability, and it affects only the applicant who applied to the FAA 
for approval of these features on the airplane.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.


0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following amended special conditions are issued as 
part of the type certification basis for Boeing Model 777 series 
airplanes.
    In addition to the airworthiness requirements of 14 CFR part 25, 
the Model 777 airplane must comply with the following requirements in 
order to be eligible for Extended Range Operation with Two-Engine 
Airplanes (ETOPS) without the requisite operating experience specified 
in Advisory Circular (AC) 120-42A:
    (a) Introduction. An approved ETOPS Type Design Assessment Plan 
covering the engine and each applicable airplane system must be 
established. The specific methods that will be used to substantiate 
compliance with the requirements of these special conditions must be 
defined in the plan. Specific systems that will undergo the complete 
analysis, testing, and development program tracking defined in 
paragraph (c) of these special conditions must be identified. Other 
airplane systems that may contribute to the overall safety of an ETOPS 
operation, but that do not warrant the rigorous type design 
requirements and relevant experience assessments defined in paragraph 
(c) of these special conditions, must be identified and agreed to by 
the FAA. Compliance must be shown for these other systems with all 
provisions of these special conditions, except paragraph (c). In 
showing compliance with these special conditions, tests and analyses 
conducted to substantiate compliance with the basic airworthiness 
standards of part 25 may be referenced, if applicable.
    (b) Engine Assessment. (1) The ETOPS eligibility of the engine must 
be determined specifically for the airplane installation for which 
early ETOPS type design approval is requested.
    (2) Procedures for an engine condition monitoring program must be 
defined and validated at the time of ETOPS type design approval. The 
engine condition monitoring program must be able to predict when an 
engine is no longer capable of providing, within certified engine 
operating limits, the maximum thrust required for a single engine 
diversion.
    (c) ETOPS Type Design Assessment. (1) Design Requirements 
Assessment. 14 CFR part 25, including applicable amendments, defines 
most of the requirements necessary to design an airplane that is 
suitable for ETOPS operation, as long as the ETOPS mission is 
considered in applying these requirements for all anticipated dispatch 
configurations. In addition to these requirements, the propulsion 
system must be designed to preclude failures or malfunctions that could 
result in an engine inflight shutdown. The applicant must identify and 
list methods of compliance for each of the applicable ETOPS 
requirements, including those specific part 25 requirements for which 
methods of compliance relative to the ETOPS mission are different from 
those traditionally used for two-engine airplanes. Paragraph (c)(3) of 
these special conditions lists certain design feature categories that 
may be affected by a consideration of the ETOPS mission in the design 
of these systems. The effects of the applicable ETOPS requirements on 
the design of any of those design feature categories listed in 
paragraph (c)(3) must be specifically addressed by this assessment.
    (2) Relevant Experience Assessment. For each system covered by the 
ETOPS Type Design Assessment, there must be an assessment of the 
relevant design, manufacturing, and operational problems experienced on 
previous airplanes built by the applicant. The assessment must include 
the applicable relevant service experience of vendor supplied systems 
or, to the extent possible, the service experience of components on 
aircraft built by other manufacturers. Specific corrective actions 
taken to preclude similar problems from occurring on the new airplane 
must be identified.
    (3) Design Features. (i) The applicant must define any design 
features implemented to comply with the design requirements listed in 
paragraph (c)(1). Consideration of the following design feature 
categories must be specifically addressed:
    (A) Airplane capabilities and capacities of the ETOPS mission;
    (B) Fuel system integrity, including consideration of uncontained 
main engine rotor burst and fuel availability as affected by cross-feed 
capability and electrical power to pumps and other components;
    (C) Fuel quantity indication to the flightcrew, including alerts 
that consider the fuel required to complete the mission, abnormal fuel 
management or transfer between tanks, and possible fuel leaks between 
the tanks and the main engines;
    (D) Communication systems for the ETOPS environment;
    (E) Navigation systems for the ETOPS environment;
    (F) Minimum single engine cruise altitude capability; and
    (G) Failure tolerant designs of cockpit indicating systems or 
avionics systems to prevent unnecessary airplane diversions.
    (ii) The applicant must define the specific design features used to 
address problems identified in the relevant service experience 
assessment of paragraph (c)(2).
    (4) Test Features. The applicant must define specific new tests, or 
enhanced tests, that will be used to assure engine and airplane system 
design integrity. These test features may be derived from the 
requirements assessment of paragraph (c)(1) and the relevant service 
experience assessment of paragraph (c)(2).

[[Page 59875]]

    (5) Analysis Features. The applicant must define specific new 
analyses, or enhanced analyses, that will be used to assure engine and 
airplane system design integrity. These analysis features may be 
derived from the requirements assessment of paragraph (c)(1) and the 
relevant service experience assessment of paragraph (c)(2).
    (6) Manufacturing, Maintenance, or Operational (Other) Features. 
The applicant must define specific new, or enhanced, manufacturing 
processes or procedures, and maintenance or operational procedures that 
are being implemented to assure engine and airplane system integrity. 
These ``other'' features may be derived from the requirements 
assessment of paragraph (c)(1) of this section and the relevant service 
experience assessment of paragraph (c)(2).
    (d) Additional ETOPS Analysis Requirements. (1) Performance and 
Failure Analyses. Engine and airplane performance and failure analyses 
required for certification must be expanded to consider ETOPS mission 
requirements, including exposure times associated with a 180-minute 
single-engine diversion and a subsequent 15-minute hold in the terminal 
airspace at the diversion airport. Consideration must be given to crew 
workload and operational implications of continued operation with 
failure effects for an extended period of time. The rationale and all 
assumptions used in the analyses must be documented, justified, and 
validated, including maintenance interval and maintainability 
assumptions.
    (2) Maintenance and Flight Operations Evaluation. The Type Design 
Assessment Plan must contain a program to systematically detect and 
correct problems occurring as a result of improper execution of 
maintenance or flight operations. Corrective actions for any problems 
found must be identified and implemented through the Problem Tracking 
and Resolution System required by paragraph (f).
    (3) Manufacturing Variability. The Type Design Assessment Plan must 
contain a program to minimize potential manufacturing problems. The 
plan should address early validation of tooling and procedures, as well 
as any related problems, as identified in paragraph (c)(2). Corrective 
actions for problems that impact the safe operation of the airplane 
must be identified and implemented through the problem tracking and 
resolution system required by paragraph (f).
    (e) Additional ETOPS Test Requirements. As part of, or in addition 
to, the testing identified in paragraph (c)(4), the following specific 
test requirements apply:
    (1) Configuration Requirements. All testing defined in paragraph 
(e) must be conducted with the configuration proposed for 
certification, and must include sufficient interfacing system hardware 
and software to simulate the actual airplane installation.
    (2) Completion of Applicable Failure Analyses. Failure analyses 
required for ETOPS type design approval must be submitted to the FAA 
prior to the start of the testing defined in paragraph (e).
    (3) Vibration Testing. Vibration testing must be conducted on the 
complete installed engine configuration to demonstrate that no damaging 
resonances exist within the operating envelope of the engine that could 
lead to component, part, or fluid line failures. The complete installed 
engine configuration includes the engine, nacelle, engine mounted 
components, and engine mounting structure up the strut to wing 
interface.
    (4) New Technology Demonstration Testing. Testing must be conducted 
to substantiate the suitability of any technology new to the applicant, 
including substantially new manufacturing techniques.
    (5) Auxiliary Power Unit Demonstration Test. If requesting credit 
for APU backup electrical power generation, one auxiliary power unit 
(APU), of the type to be certificated with the airplane, must complete 
3000 equivalent airplane operational cycles.
    (6) Engine Demonstration Test. One engine of each type to be 
certificated with the airplane must complete 3000 equivalent airplane 
operational cycles. The engine must be configured with a complete 
airplane nacelle package for this demonstration, including engine-
mounted equipment except for any configuration differences necessary to 
accommodate test instrumentation and test stand interfaces with the 
engine nacelle package. At completion of the engine demonstration test, 
the engine and airplane nacelle test hardware must undergo a complete 
teardown inspection. This inspection must be conducted in a manner to 
identify abnormal conditions that could become potential sources of 
engine inflight shutdown. An analysis of any abnormal conditions found 
must consider the possible consequences of similar occurrences in 
service to determine if they may become sources of engine inflight 
shutdowns, power loss, or inability to control engine thrust. Any 
potential sources of engine inflight shutdown identified must be 
corrected in accordance with paragraph (g)(2).
    (7) Airplane Demonstration Test. In addition to the function and 
reliability testing required by 14 CFR 21.35(b)(2), for each engine 
type to be certificated with the airplane, one or more airplanes must 
complete flight testing which demonstrates that the aircraft, its 
components, and equipment, are capable of and function properly during 
long range operations and airplane diversions, including engine-
inoperative diversions.
    (i) The flight conditions must expose the airplane to 
representative operational variations based on the airplane's system 
and equipment design and the intended use of the airplane including:
    (A) Engine inoperative maximum length diversions to demonstrate the 
airplane and propulsion system's capability to safely conduct a 
diversion.
    (B) Non-normal conditions to demonstrate the airplane's capability 
to safely divert under worst case probable system failure conditions.
    (C) Simulated airline operations including normal cruise altitudes, 
step climbs, and maximum expected flight durations out of and into a 
variety of departure and arrival airports.
    (D) Diversions to worldwide airports representative of those 
intended as operational alternates.
    (E) Repeated exposure to humid and inclement weather on the ground 
followed by long-range operation at normal cruise altitude.
    (ii) The flight testing must validate expected airplane flying 
qualities and performance considering engine failure, electrical power 
losses, etc. The testing must demonstrate the adequacy of remaining 
airplane systems and performance and flightcrew ability to deal with an 
emergency considering remaining flight deck information following 
expected failure conditions.
    (iii) The engine-inoperative diversions must be evenly distributed 
among the number of engines in the applicant's flight test program.
    (iv) The test airplane(s) must be operated and maintained using the 
recommended operations and maintenance manual procedures during the 
airplane demonstration test.
    (v) At completion of the airplane demonstration test, the test 
engines and engine-mounted equipment must undergo a complete external 
on-wing visual inspection. The engines must also undergo a complete 
internal visual inspection. These inspections must be conducted in a 
manner to identify abnormal conditions that could become potential 
sources of engine inflight shutdowns. An analysis of any abnormal 
conditions found must

[[Page 59876]]

consider the possible consequences of similar occurrences in service to 
determine if they may become sources of engine inflight shutdowns. Any 
potential sources of engine inflight shutdown that are identified must 
be corrected in accordance with paragraph (g)(2).
    (f) Problem Tracking System. An FAA-approved problem tracking 
system must be established to address problems encountered on the 
engine and airplane systems that could affect the safety of ETOPS 
operations.
    (1) The system must contain a means for the prompt identification 
of those problems that could impact the safety of ETOPS operations in 
order that they may be resolved in a timely manner.
    (2) The system must contain the process for the timely notification 
to the responsible FAA office of all relevant problems encountered, and 
corrective actions deemed necessary, in a manner that allows for 
appropriate FAA review of all planned corrective actions.
    (3) The system must be in effect during the phases of airplane 
development that will be used to assess early ETOPS eligibility, and 
for at least the first 250,000 engine-hours of fleet operating 
experience after the airplane enters revenue service. For the revenue 
service period, this system must define the sources and content of in-
service data that will be made available to the manufacturers in 
support of the problem tracking system. The content of the data 
provided must include, as a minimum, the data necessary to evaluate the 
specific cause of all service incidents reportable under Sec. 21.3(c) 
of part 21, in addition to any other failure or malfunction that could 
prevent safe flight and landing of the airplane, or affect the ability 
of the crew to cope with adverse operating conditions.
    (4) Corrective actions for all problems discovered during the 
development and certification test program that could affect the safety 
of ETOPS operations, or the intended function of systems whose use is 
relied upon to accomplish the ETOPS mission, must be identified and 
implemented in accordance with paragraph (g)(2). If, during the 
certification program, it is discovered that a fault has developed that 
requires significant rework of manufacturing, maintenance, and/or 
operational procedures, the FAA will review the ETOPS suitability of 
the affected system and interfacing hardware and identify any 
additional actions to be accomplished to substantiate the corrective 
actions.
    (5) For each engine type to be certificated with the airplane, the 
system must include provisions for an accelerated engine cyclic 
endurance test program that will accumulate cycles on one 
representative production-equivalent propulsion system in advance of 
the high-cycle revenue fleet engine. This test program will assist the 
applicant and the FAA in identifying and correcting problems before 
they occur in revenue service. This program must be in place for, at a 
minimum, the first 250,000 engine-hours of fleet operating experience 
after the airplane enters revenue service. The representative 
production-equivalent propulsion system may, at the manufacturer's 
discretion, be used for other fleet support activities.
    (g) Reliability Assessment Board. (1) An FAA Reliability Assessment 
Board will be formed to evaluate the suitability of the airplane for 
ETOPS approval and make a recommendation to the Manager, Transport 
Airplane Directorate, regarding the adequacy of the type design for 
180-minute ETOPS operation. The purpose of this board will be:
    (i) To periodically review the development and certification flight 
test program accomplishments from both type design and operational 
perspectives;
    (ii) To ensure that all specific problems, as well as their 
implications on the effectiveness of the Early ETOPS process, are 
resolved; and
    (iii) To assess the design suitability for ETOPS. The board will 
consider design, maintenance, manufacturing, and operational aspects of 
the type design when finding suitability for ETOPS approval.
    (2) The FAA Reliability Assessment Board will review and evaluate 
the data from the problem tracking and resolution system to establish 
compliance with the requirements of paragraph (h). The board will 
evaluate the overall type design for ETOPS suitability as demonstrated 
in flight test, and the Airplane Demonstration Test, considering all 
resolutions of problems. The following suitability criteria will be 
applied:
    (i) Sources of engine shutdown/thrust loss, engine anomalies, or 
airplane system problems that have a potential significant adverse 
effect on in-service safety will be resolved.
    (ii) Resolutions are identified for all items in paragraph (i) with 
analysis and/or testing to show all resolutions are effective. These 
resolutions may be accomplished through one or more of the following 
categories:

Design change
Operating procedure revision
Maintenance procedure revision
Manufacturing change

    (iii) The resolutions of paragraphs (i) and (ii) will be 
incorporated prior to entry into service.
    (iv) The engine shutdown history of the test program indicates that 
the engine reliability of the configuration is suitable for the ETOPS 
approval being considered.
    (v) Where interim resolutions having operational impact are 
defined, the cumulative effect must be determined to be acceptable.
    (vi) System or component failures experienced during the program 
are consistent with the assumptions made in the failure analyses.
    (h) Reliability Demonstration Acceptance Criteria.
    (1) For the engine and airplane systems, the type and frequency of 
failures that occur during the airplane flight test program and the 
Airplane Demonstration Test must be consistent with the type and 
frequency of failures or malfunctions that would be expected to occur 
on presently certified 180-minute ETOPS airplanes. The failures to be 
considered are those associated with system components that conform to 
the type design requested for certification. The Reliability Assessment 
Board will determine compliance with this requirement based on an 
evaluation of the problem reporting system data, considering system 
redundancies, failure significance, problem resolution, and engineering 
judgment.
    (2) Corrective action for any of the following classes of problems 
occurring during the testing identified in paragraph (h)(1) that 
requires a major system redesign would delay ETOPS type design 
approval, or result in approval of a reduced single-engine diversion 
time, unless corrective action has been substantiated to, and accepted 
by, the FAA Reliability Assessment Board:
    (i) Any source of unplanned inflight shutdown or loss of thrust.
    (ii) Any problem that jeopardizes the safety of an airplane 
diversion.
    (3) The FAA Reliability Assessment Board must determine that the 
suitability criteria of paragraph (g)(2) have been met.
    (i) Demonstration of Compliance. In order to be eligible for 180-
minute ETOPS type design approval, the following conditions apply:
    (1) The engine assessment has been completed and eligibility for 
ETOPS operation has been approved by the FAA Engine Certification 
Office.
    (2) All design, manufacturing, maintenance, operational, and other 
features necessary to meet the ETOPS requirements of paragraph (c)(1), 
and to resolve the problems identified in

[[Page 59877]]

paragraph (c)(2), have been successfully implemented.
    (3) The identified test and analysis features in paragraph (c)(4) 
and (c)(5) have been shown to be effective in validating the successful 
implementation of the features in paragraph (i)(2).
    (4) The additional analysis requirements of paragraph (d) have been 
completed and the results have been approved.
    (5) The additional test requirements of paragraph (e) have been 
successfully completed.
    (6) All significant problems identified in accordance with 
paragraph (f) have been resolved, and fixes substantiated to be 
effective have been implemented.
    (7) The accelerated engine cyclic endurance test program of 
paragraph (f)(5) must be in place.
    (8) Compliance with the reliability demonstration acceptance 
criteria of paragraph (h) has been found by the Reliability Assessment 
Board.

    Issued in Renton, Washington, on October 8, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-26378 Filed 10-17-03; 8:45 am]
BILLING CODE 4910-13-P