[Federal Register Volume 59, Number 141 (Monday, July 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17593]


[[Page Unknown]]

[Federal Register: July 25, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-07-AD; Amendment 39-8976; AD 94-15-05]

 

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Boeing Model 747-400 series airplanes, that requires 
various inspections and functional tests of the thrust reverser control 
and indication system, and correction of any discrepancy found. This 
amendment is prompted by an investigation to determine the 
controllability of Model 747 series airplanes following an in-flight 
thrust reverser deployment, which has revealed that, in the event of 
thrust reverser deployment during high-speed climb or during cruise, 
these airplanes could experience control problems. The actions 
specified by this AD are intended to ensure the integrity of the fail 
safe features of the thrust reverser system by preventing possible 
failure modes in the thrust reverser control system that can result in 
inadvertent deployment of a thrust reverser during flight.

DATES: Effective August 24, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 24, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jon Regimbal, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (206) 227-2687; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Boeing Model 747-400 series 
airplanes was published in the Federal Register on March 4, 1994 (59 FR 
10336). That action proposed to require various inspections and 
functional tests of the thrust reverser control and indication system, 
and correction of any discrepancy found. -
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received. -
    One commenter supports the proposed rule. -
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, requests that the proposed repetitive inspections and 
tests be withdrawn since those actions will be added to the revised 
Maintenance Planning Document. The ATA acknowledges that the proposed 
repetitive actions may not be incorporated uniformly into every 
operator's maintenance program unless an AD is issued. Therefore, the 
ATA asks that another provision be added to the proposal as follows: 
Within 3 months after the effective date of the AD, revise the FAA-
approved maintenance inspection program to include a functional test of 
the thrust reverser control and indication system at an initial 15-
month interval. Inspections for damage to the bullnose seal would be 
conducted at an initial 1,500 flight hour interval. The AD would no 
longer be applicable for operators that have acceptably revised the 
maintenance program. Operators complying with this paragraph could use 
an alternative recordkeeping method in lieu of that required by section 
91.417 or 121.380 of the Federal Aviation Regulations (14 CFR 91.417 or 
121.380). The FAA would be defined as the cognizant Principal 
Maintenance Inspector (PMI) for operators electing this alternative.
    The ATA believes that its suggestion should be adopted because the 
proposed repetitive actions will likely continue for as long as Model 
747-400 series airplanes are operated. The ATA acknowledges that, while 
numerous AD's that require repetitive inspections continue for the life 
of the aircraft, it has either been shown that a satisfactory 
terminating action has not been developed or that service experience 
has shown that control of the inspections cannot be administered safely 
through an operator's maintenance program. The ATA states that its 
proposal is intended to minimize the impact of the AD process on an 
operator's maintenance program and cites other AD's that contain 
provisions similar to its proposal.
    The FAA recognizes the ATA's concerns regarding the requirement for 
repetitive inspections and tests of the thrust reverser control and 
indication systems. However, the FAA finds that this requirement is 
necessary in order to provide an adequate level of safety by addressing 
the specified unsafe condition. Further, the FAA determined the 
required repetitive intervals based on the service history of similar 
components and on an analysis of the system design to predict the 
reliability of the system during the service life of the aircraft. 
Lengthening these intervals would only be appropriate when a sufficient 
sample of systems is allowed to operate through an entire system 
overhaul cycle; adjustments made prior to that time may not account for 
the effects of age and wear.
    The FAA finds that addressing inspections and tests of the thrust 
reverser control and indication systems in a document that is not FAA-
approved, such as a Maintenance Planning Document, will not ensure an 
acceptable level of safety with regard to the thrust reverser system. 
The ATA's suggested provision for accomplishment of the inspections and 
tests would permit each operator to determine whether and how often 
these actions should be conducted. In light of the severity of the 
unsafe condition, however, the FAA has determined that allowing this 
degree of operator discretion is not appropriate at this time. 
Therefore, this AD is necessary to ensure that operators accomplish the 
repetitive actions in a common manner and at common intervals.
    One commenter requests that the proposed compliance time for the 
initial inspections and functional tests of the thrust reverser control 
and indication systems be extended from 6 to 12 months. This commenter 
offers no justification for the request. A second commenter indicates a 
false impression that a 12-month compliance time was proposed for these 
inspections and functional tests, and requests that the compliance time 
be expressed in terms of maintenance checks (specifically, ``C'' 
checks) or 15 months to coincide with regularly scheduled maintenance. 
(The FAA notes that no 12-month compliance time is specified for any 
requirement contained in the proposal.) Another commenter requests that 
the compliance times be specified in terms of maintenance check 
intervals (``A'' checks, ``C'' checks, etc.). The commenter provides no 
justification for this request.
    The FAA concurs partially. Since only two comments were received in 
response to the proposed 6-month compliance time, the FAA assumes that 
most operators are able to accommodate that proposed compliance time. 
In light of safety considerations, the FAA finds that a short initial 
compliance time for the inspections and functional tests is warranted. 
However, upon reconsideration, the FAA considers that extending the 
proposed compliance time by 3 additional months will not adversely 
affect safety, and will allow the required actions to be performed at a 
base during regularly scheduled maintenance where special equipment and 
trained maintenance personnel will be available, if necessary. 
Paragraphs (a)(2), (b)(2), and (c) of the final rule have been revised 
to specify a compliance time of 9 months for the initial inspections 
and functional tests of the thrust reverser control and indication 
systems.
    The FAA does not agree that the compliance times specified in the 
final rule should be expressed in terms of maintenance check intervals. 
Since maintenance schedules vary from operator to operator, there would 
be no assurance that the actions will be accomplished during those 
maximum intervals. The FAA has determined that the compliance times, as 
specified in the final rule, represent the maximum intervals of time 
allowable for the affected airplanes to continue to operate prior to 
accomplishing the required actions without compromising safety.
    Several commenters request that the proposed compliance time for 
repetitive inspections and functional tests of the thrust reverser 
control and indication systems [specified in paragraphs (a)(2), (b)(2), 
and (c) of the proposal] be extended from the proposed 15-month 
intervals to accommodate current or future scheduled ``C'' check 
maintenance intervals. Two commenters propose extension of the 
compliance time to 18-month intervals. One commenter indicates that 
Boeing Alert Service Bulletin 747-78A2115, Revision 1, dated March 10, 
1994, recommends inspection intervals of 15 months or 5,000 flight 
hours.
    The FAA concurs partially. As discussed previously, the FAA does 
not agree that these compliance times should be expressed in terms of 
maintenance check intervals. However, the FAA does concur with the 
commenters' requests to extend the proposed compliance time to 18 
months. Extending the compliance time by 3 additional months will not 
adversely affect safety, and will allow the inspections and tests to be 
performed at a base during regularly scheduled maintenance where 
special equipment and trained maintenance personnel will be available, 
if necessary. Paragraphs (a)(2), (b)(2), and (c) of the final rule have 
been revised to specify a compliance time of 18 months for repetitive 
inspections and functional tests of the thrust reverser control and 
indication systems.
    Several commenters request that paragraph (d) of the proposed rule 
be revised to allow dispatch with a thrust reverser inoperative in 
accordance with the FAA-approved Master Minimum Equipment List (MMEL) 
if any discrepancy is found during the required inspections and tests. 
Several commenters point out that allowing dispatch with a thrust 
reverser inoperative will provide operators time to obtain parts and 
perform any necessary corrective action. One commenter explains that, 
without this change, the dispatch capability of the airplane would be 
downgraded for problems such as proximity sensor adjustments or auto 
restow chafing, which are not related to the integrity of the stow lock 
feature. One commenter requests 14-day dispatch relief.
    The FAA concurs partially. The FAA agrees that an option for 
dispatch relief may be allowed in accordance with an operator's FAA-
approved Minimum Equipment List (MEL). However, the FAA does not concur 
with the commenter's request for 14-day dispatch relief, since the MMEL 
specifies 10-day dispatch relief. The FAA has revised paragraph (d) of 
the final rule to provide an alternative for an airplane to be operated 
in accordance with existing provisions and limitations specified in the 
MEL, provided that no more than one thrust reverser on the airplane is 
inoperative. -Three commenters request that the proposed interval of 
1,000 hours time-in-service for repetitive inspections of the bullnose 
seal and tests of the lock mechanism and of the position switch module 
and cone brake be extended to coincide with operators' scheduled 
maintenance intervals and to reduce the economic impact of the proposed 
actions. One commenter suggests a repetitive interval of 1,300 hours 
time-in-service. The second commenter proposes that the interval be 
extended to 1,500 hours time-in-service. The third commenter recommends 
that these actions be required every 15 months or during ``C'' checks.
    The FAA does not concur. The FAA based the repetitive inspection 
interval on data obtained from a reliability analysis submitted by 
Boeing prior to the issuance of the proposed rule. The FAA based the 
proposed interval of 1,000 hours time-in-service on that analysis and 
on the fact that affected operators conduct ``A'' checks at intervals 
of approximately 450 hours time-in-service. The FAA's intent was that 
the proposed inspections and tests be conducted during every other 
regularly scheduled ``A'' check, when the airplanes would be located at 
a base where special equipment and trained personnel would be readily 
available, if necessary. Further, the FAA has received no supporting 
technical analysis to supplement or refute the manufacturer's original 
reliability analysis. The FAA has determined that the compliance time, 
as proposed, represents the maximum interval of time allowable for the 
affected airplanes to accomplish the required repetitive actions 
without compromising safety.
    One commenter requests that a statement be added to the proposed 
rule to indicate that the AD is considered to be interim action. The 
FAA acknowledges that this AD is interim action, as specified in the 
preamble to the proposed rule. The manufacturer has advised that it 
currently is developing a modification that will positively address the 
unsafe condition addressed by this AD, and that the modification should 
be available within approximately 24 months. Once this modification is 
developed, approved, and available, the FAA may consider additional 
rulemaking.
    One commenter requests that the proposal be revised to require that 
operators report results from all inspections and tests, rather than 
only initial inspections and tests, and that these results be used to 
justify adjustments of inspection intervals or cancellation of 
inspections. The commenter offers no justification for this request. 
The FAA does not concur. The FAA is interested in the initial 
inspection results for the purpose of determining the present state of 
thrust reverser systems throughout the fleet. Since the actions 
required by this AD are considered to be interim action and terminating 
action is imminent, the FAA finds that gathering information for the 
purpose of adjusting inspection intervals and cancelling inspections is 
not needed and would pose an unnecessary burden on operators.
    One commenter requests that the FAA review the probability 
calculations made by Boeing in determining that an unsafe condition 
exists. The commenter states that if the probability of inadvertent 
thrust reverser deployment is lower than 1 in 109 flight hours, an 
AD would not be required. The commenter points out two factors that 
would reduce controllability: deployment of an outboard thrust 
reverser, and deployment of that reverser during climb. Neither of 
these factors was accounted for in the probability study that Boeing 
presented to the operators. In addition, for Model 747-400 series 
airplanes equipped with General Electric CF6-80C2 engines, deployment 
of a single thrust reverser sleeve half is possible, and deployment of 
a single sleeve half was assumed to have the same effect on airplane 
controllability as full (both halves) deployment of a thrust reverser.
    The FAA does not concur. The analysis presented by Boeing to the 
FAA states clearly that the effect of deployment of an inboard thrust 
reverser, or the effect of deployment of a single outboard thrust 
reverser sleeve, had not yet been quantified. At that time, Boeing and 
the FAA recognized the need for further study. However, in light of the 
experience gained during investigation of the accident discussed in the 
preamble to the proposed rule, Boeing had identified design 
deficiencies that needed to be addressed as soon as practicable to 
ensure the safety of the Model 747 fleet. The FAA did not determine 
that an AD was warranted solely on the basis that a particular 
probability threshold of 1 in 109 flight hours had been exceeded. 
Rather, the FAA based its determination on the fact that design 
deficiencies exist that could lead to an unsafe condition (reduction in 
or loss of controllability of the airplane), which can be compensated 
for by periodic inspections and tests until a design change becomes 
available.
    Since the issuance of the proposal, Boeing has issued Revision 1 of 
Boeing Alert Service Bulletins 747-78A2112, dated March 7, 1994; 747-
78A2113, dated March 10, 1994; and 747-78A2115, dated March 4, 1994. 
(The original issues of these service bulletins were cited in the 
proposal as the appropriate sources of service information.) These 
alert service bulletin revisions reclassify the service bulletin type 
from standard to alert, recommend certain revised compliance times to 
coincide with operators' maintenance schedules, and revise certain test 
procedures. The FAA has reviewed and approved these alert service 
bulletins and has revised the final rule to reflect these latest 
revisions as additional sources of service information. In addition, 
the FAA has revised the final rule to specify the appropriate 
paragraphs of the Accomplishment Instructions of these alert service 
bulletins for performing the actions required by this AD.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    This is considered to be interim action until final action is 
identified for these airplanes, at which time the FAA may consider 
further rulemaking.
    There are approximately 286 Model 747-400 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 39 Model 
747-400 series airplanes powered by Pratt & Whitney PW4000 series 
engines of U.S. registry will be affected by this AD, that it will take 
approximately 48 work hours per airplane to accomplish the required 
actions, and that the average labor rate is $55 per work hour. Based on 
these figures, the total cost impact of the AD on U.S. operators of 
Model 747-400 series airplanes powered by Pratt & Whitney PW4000 series 
engines is estimated to be $102,960, or $2,640 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    Currently, there are no Model 747-400 series airplanes powered by 
General Electric CF6-80C2 series engines on the U.S. Register. However, 
should one of these airplanes be imported and placed on the U.S. 
Register in the future, it will require approximately 60 work hours to 
accomplish the required actions, at an average labor charge of $55 per 
work hour. Based on these figures, the total cost impact of this AD is 
estimated to be $3,300 per airplane.
    Additionally, there are no Model 747-400 series airplanes powered 
by Rolls-Royce RB211-524G/H series engines on the U.S. Register at this 
time. However, should one of these airplanes be imported and placed on 
the U.S. Register in the future, it will require approximately 30 hours 
to accomplish the required actions, at an average labor charge of $55 
per work hour. Based on these figures, the total cost impact of this AD 
is estimated to be $1,650 per airplane.
    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

94-15-05 Boeing: Amendment 39-8976. Docket 94-NM-07-AD.

    Applicability: All Model 747-400 series airplanes, certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure the integrity of the fail safe features of the thrust 
reverser system, accomplish the following:
    (a) For Model 747-400 series airplanes powered by Pratt & 
Whitney PW4000 series engines: Accomplish paragraphs (a)(1) and 
(a)(2) of this AD.
    (1) Within 90 days after the effective date of this AD, perform 
an inspection to detect damage to the bullnose seal on the 
translating sleeve of the thrust reverser, and perform a test of the 
lock mechanism of the center locking actuator, in accordance with 
paragraphs III.C. and III.E. of the Accomplishment Instructions of 
Boeing Service Bulletin 747-78-2112, dated November 11, 1993; or 
paragraphs III.E. and III.H. of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-78A2112, Revision 1, dated March 
7, 1994. Repeat this inspection and test thereafter at intervals not 
to exceed 1,000 hours time-in-service.
    (2) Within 9 months after the effective date of this AD, perform 
inspections and functional tests of the thrust reverser control and 
indication systems in accordance with paragraphs III.A., III.B., 
III.D., and III.F. through III.M. of the Accomplishment Instructions 
of Boeing Service Bulletin 747-78-2112, dated November 11, 1993; or 
paragraphs III.C., III.D., III.F., III.G., and III.I. through III.P. 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-78A2112, Revision 1, dated March 7, 1994. Repeat these 
inspections and functional tests thereafter at intervals not to 
exceed 18 months.
    (b) For Model 747-400 series airplanes powered by General 
Electric CF6-80C2 series engines: Accomplish paragraphs (b)(1) and 
(b)(2) of this AD.
    (1) Within 90 days after the effective date of this AD, perform 
an inspection to detect damage to the bullnose seal on the 
translating sleeve of the thrust reverser, and a continuity test of 
the position switch module of the center drive unit (CDU) and a cone 
brake test of the CDU, in accordance with paragraphs III.B. and 
III.C. of the Accomplishment Instructions of Boeing Service Bulletin 
747-78-2113, dated November 11, 1993; or paragraphs III.E. through 
III.G. of Boeing Alert Service Bulletin 747-78A2113, Revision 1, 
dated March 10, 1994. Repeat the inspection and tests thereafter at 
intervals not to exceed 1,000 hours time-in-service.
    (2) Within 9 months after the effective date of this AD, perform 
inspections and functional tests of the thrust reverser control and 
indication systems in accordance with paragraphs III.A., III.D., 
III.F., III.G., III.H., and III.J. through III.M. of the 
Accomplishment Instructions of Boeing Service Bulletin 747-78-2113, 
dated November 11, 1993; or paragraphs III.D. and III.H. through 
III.N. of Boeing Alert Service Bulletin 747-78A2113, Revision 1, 
dated March 10, 1994. Repeat these inspections and functional tests 
thereafter at intervals not to exceed 18 months.
    (c) For Model 747-400 series airplanes powered by Rolls-Royce 
RB211-524G/H series engines: Within 9 months after the effective 
date of this AD, and thereafter at intervals not to exceed 18 
months, perform inspections and functional tests of the thrust 
reverser control and indication systems in accordance with 
paragraphs III.D. through III.K. of the Accomplishment Instructions 
of Boeing Service Bulletin 747-78-2115, dated October 28, 1993; or 
paragraphs III.D. through III.L. of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 747-78A2115, Revision 1, dated 
March 4, 1994.
    (d) If any of the inspections and/or functional tests required 
by this AD cannot be successfully performed, or if any discrepancy 
is found during those inspections and/or functional tests, 
accomplish either paragraph (d)(1) or (d)(2) of this AD.
    (1) Prior to further flight, correct the discrepancy found, in 
accordance with Boeing Service Bulletin 747-78-2112, dated November 
11, 1993, or Boeing Alert Service Bulletin 747-78A2112, Revision 1, 
dated March 7, 1994 (for Model 747-400 series airplanes powered by 
Pratt & Whitney PW4000 series engines); Boeing Service Bulletin 747-
78-2113, dated November 11, 1993, or Boeing Alert Service Bulletin 
747-78A2113, Revision 1, dated March 10, 1994 (for Model 747-400 
series airplanes powered by General Electric CF6-80C2 series 
engines); or Boeing Service Bulletin 747-78-2115, dated October 28, 
1993, or Boeing Alert Service Bulletin 747-78A2115, Revision 1, 
dated March 4, 1994 (for Model 747-400 series airplanes powered by 
Rolls-Royce RB211-524G/H series engines); as applicable. Or
    (2) The airplane may be operated in accordance with the 
provisions and limitations specified in an operator's FAA-approved 
Minimum Equipment List (MEL), provided that no more than one thrust 
reverser on the airplane is inoperative.
    (e) Within 10 days after performing each initial inspection and 
test required by this AD, submit a report of the inspection and/or 
test results, both positive and negative, to the FAA, Seattle 
Aircraft Certification Office (ACO), ANM-100S, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; fax (206) 227-1181. Information 
collection requirements contained in this regulation have been 
approved by the Office of Management and Budget (OMB) under the 
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et 
seq.) and have been assigned OMB Control Number 2120-0056.
    (f) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO, FAA, Transport 
Airplane Directorate. Operators shall submit their requests through 
an appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (g) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (h) The actions shall be done in accordance with Boeing Service 
Bulletin 747-78-2112, dated November 11, 1993; Boeing Alert Service 
Bulletin 747-78A2112, Revision 1, dated March 7, 1994; Boeing 
Service Bulletin 747-78-2113, dated November 11, 1993; Boeing Alert 
Service Bulletin 747-78A2113, Revision 1, dated March 10, 1994; 
Boeing Service Bulletin 747-78-2115, dated October 28, 1993; or 
Boeing Alert Service Bulletin 747-78A2115, Revision 1, dated March 
4, 1994; as applicable. This incorporation by reference was approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from Boeing 
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-
2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.
    (i) This amendment becomes effective on August 24, 1994.

    Issued in Renton, Washington, on July 13, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-17593 Filed 7-22-94; 8:45 am]
BILLING CODE 4910-13-U