[Federal Register Volume 71, Number 138 (Wednesday, July 19, 2006)]
[Proposed Rules]
[Pages 40940-40942]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-11415]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25388; Directorate Identifier 2006-NM-086-AD]
RIN 2120-AA64


Airworthiness Directives; BAE Systems (Operations) Limited Model 
BAe 146 and Avro 146-RJ Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ 
airplanes equipped with certain hydraulic accumulators. This proposed 
AD would require inspecting the hydraulic accumulators to identify 
certain serial numbers, and replacing any affected accumulator with a 
new or serviceable accumulator. Operators may delay doing the 
replacement by doing repetitive inspections of the affected hydraulic 
accumulators for signs of failure (leaking or cracking), and replacing 
any failed accumulator with a new or serviceable unit. This proposed AD 
results from a report that one hydraulic accumulator failed in service, 
which caused the loss of the yellow hydraulic system when the airplane 
was configured for landing. We are proposing this AD to prevent damage 
to the pressure skin, failure of certain hydraulic systems, 
contamination of the cabin with hydraulic mist, increased workload for 
the flightcrew associated with the loss of one or more hydraulic 
circuits, and consequent reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by August 18, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact British Aerospace Regional Aircraft American Support, 13850 
Mclearen Road, Herndon, Virginia 20171, for service information 
identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, Transport Airplane Directorate, FAA, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2125; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
25388; Directorate Identifier 2006-NM-086-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    We have received reports that an unsafe condition may exist on BAE 
Systems (Operations) Limited Model BAe 146 and Avro 146-RJ airplanes 
that have hydraulic accumulators, part number (P/N) AIR91666-0, -1, and 
-2, installed. The European Aviation Safety Agency (EASA) advises that 
the manufacturer identified two batches of defective hydraulic 
accumulators after one accumulator burst in service, which caused the 
loss of the yellow hydraulic system when the airplane was configured 
for landing. The landing was completed without further incident.
    The accumulator was found in the hydraulics bay, detached from its 
mounting, and shrapnel debris had punctured the pressure skin. 
Metallurgical examination revealed a pre-existing flaw in the 
accumulator cylinder casing. A second accumulator with a material flaw 
in the cylinder casing was identified by non-destructive testing during 
component overhaul. Further investigation showed that a total of 54 
accumulators, P/N AIR91666, were manufactured without the required 
inspection processes being applied to the cylinder casings. Material 
flaws within the cylinder could cause the unit to burst in service, 
resulting in damage to the pressure skin and loss of any services 
supplied by the system that is connected to the failed accumulator. 
These services include flaps, lift and roll spoilers, rudder, airbrake, 
landing gear actuators, nose wheel steering, and wheel brakes. This 
condition, if not corrected, could result in damage to the pressure 
skin, failure of certain hydraulic systems, contamination of the cabin 
with hydraulic mist, increased workload for the flightcrew associated 
with the loss of one or more hydraulic circuits, and consequent reduced 
controllability of the airplane.

Relevant Service Information

    BAE Systems (Operations) Limited has issued Service Bulletin 
ISB.29-A046, dated March 14, 2006. The service bulletin describes 
procedures for inspecting to identify specified serial numbers of 
hydraulic accumulators with P/N AIR91666-0, -1, and -2 in the yellow 
and green hydraulic systems and, if applicable, the forward airstairs. 
If any affected serial number is

[[Page 40941]]

installed, the service bulletin provides procedures for replacing it 
before further flight with a new or serviceable unit. A serviceable 
accumulator is defined as one that is not part of the affected batch, 
or one on which APPH Service Bulletin AIR91666-29-02, dated March 2006 
(described below), has been accomplished. In lieu of replacement, the 
service bulletin specifies doing the replacement within 135 days 
provided that operators do repetitive detailed visual inspections for 
signs of failure (leaks or cracking), and replacing the accumulator 
with a new or serviceable unit if necessary. The repetitive interval is 
48 hours, or before further flight following a report of hydraulic 
fumes in the cabin air supply, or after a hydraulic fluid low-level 
warning. Accomplishing the actions specified in the service information 
is intended to adequately address the unsafe condition.
    The EASA mandated Service Bulletin ISB.29-A046, and issued 
emergency airworthiness directive 2006-0061-E [Corrected], dated March 
17, 2006, to ensure the continued airworthiness of these airplanes in 
the European Union.
    The BAE Systems (Operations) Limited service bulletin refers to 
APPH Service Bulletin AIR91666-29-02, dated March 2006, as an 
additional source of service information for determining if an 
accumulator is a serviceable accumulator. The procedures include 
disassembling the accumulator cylinder and testing it for cracking.

U.S. Type Certification of the Airplane

    These airplane models are manufactured in the United Kingdom and 
are type certificated for operation in the United States under the 
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) and the applicable bilateral airworthiness agreement. Pursuant 
to FAA Order 8100.14A, ``Interim Procedures for Working with the 
European Community on Airworthiness Certification and Continued 
Airworthiness,'' dated August 12, 2005, the EASA has kept the FAA 
informed of the situation described above. We have examined the EASA's 
findings, evaluated all pertinent information, and determined that we 
need to issue an AD for products of this type design that are 
certificated for operation in the United States.

Clarifications of Service Information

    Although the BAE Systems (Operations) Limited service bulletin does 
not specify procedures to follow if more than one affected hydraulic 
accumulator is found on a single airplane, this proposed AD, in 
parallel with the EASA airworthiness directive, would allow only one 
affected hydraulic accumulator to remain in service on the airplane and 
subject to the proposed repetitive inspections.
    The BAE Systems (Operations) Limited service bulletin specifies a 
detailed visual inspection for signs of leaking. In this proposed AD, 
we refer to that inspection as a ``detailed inspection.'' We have 
included a definition of a detailed inspection in Note 2 of this 
proposed AD.
    Although the BAE Systems (Operations) Limited service bulletin 
specifies replacing the accumulator within 135 days provided that 
operators do repetitive detailed visual inspections for signs of 
failure, this proposed AD would require this replacement within 75 days 
after the effective date of this proposed AD. This compliance time 
parallels the compliance time for the replacement that is specified in 
EASA emergency airworthiness directive 2006-0061-E [Corrected].

Changes to 14 CFR Part 39/Effect on the AD Relating to Special Flight 
Permits

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance (AMOCs). This material is included in part 39, except that 
the office authorized to approve AMOCs is identified in each individual 
AD. However, as amended, part 39 provides for the FAA to add special 
requirements for operating an airplane to a repair facility to do the 
work required by an airworthiness directive. For the purposes of this 
proposed AD, we have determined that such a special flight permit would 
be limited before all affected hydraulic actuators are replaced on the 
airplane. A special flight permit is allowed only if the airplane has 
not flown more than 5 flight cycles since the last inspection done in 
accordance with paragraph (g)(2) or (g)(3) of this proposed AD, as 
applicable; and if the flight can be accomplished in one flight cycle 
with the airplane unpressurized.

Costs of Compliance

    This proposed AD would affect about 42 airplanes of U.S. registry. 
The proposed inspection to determine the serial number would take about 
1 work hour per airplane, at an average labor rate of $80 per work 
hour. Based on these figures, the estimated cost of the proposed AD for 
U.S. operators is $3,360, or $80 per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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


[[Page 40942]]


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


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

BAE Systems (Operations) Limited (Formerly British Aerospace 
Regional Aircraft): Docket No. FAA-2006-25388; Directorate 
Identifier 2006-NM-086-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by August 
18, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all BAE Systems (Operations) Limited 
Model BAe 146-100A, -200A, and -300A series airplanes; and Model 
Avro 146-RJ70A, 146-RJ85A, and 146-RJ100A airplanes; certificated in 
any category; equipped with hydraulic accumulators part number (P/N) 
AIR91666-0, -1, or -2 installed.

Unsafe Condition

    (d) This AD results from report that one hydraulic accumulator 
failed in service, which caused the loss of the yellow hydraulic 
system when the airplane was configured for landing. We are issuing 
this AD to prevent damage to the pressure skin, failure of certain 
hydraulic systems, contamination of the cabin with hydraulic mist, 
increased workload for the flightcrew associated with the loss of 
one or more hydraulic circuits, and consequent reduced 
controllability of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Inspection To Determine Serial Number

    (f) Within 48 hours after the effective date of this AD, inspect 
all P/N AIR91666-0, -1, and -2 hydraulic accumulators to determine 
whether any hydraulic accumulator is installed that has a serial 
number (S/N) identified in paragraph C of the Accomplishment 
Instructions of BAE Systems (Operations) Limited Service Bulletin 
ISB.29-A046, dated March 14, 2006. A review of airplane maintenance 
records is acceptable in lieu of this inspection if the S/N can be 
conclusively determined from that review.

Replacement or Repetitive Inspections

    (g) If any accumulator with an affected S/N is identified during 
the inspection required by paragraph (f) of this AD, do the action 
in paragraph (g)(1) or (g)(2) of this AD. Do all actions in 
accordance with the Accomplishment Instructions of BAE Systems 
(Operations) Limited Service Bulletin ISB.29-A046, dated March 14, 
2006, except where the service bulletin specifies to submit certain 
information to the manufacturer, this AD does not include that 
requirement.
    (1) Before further flight: Replace the hydraulic accumulator 
with a new or serviceable accumulator.
    (2) Before further flight: Do a detailed inspection for signs of 
failure (leaking or cracking) of the hydraulic accumulator, and 
replace any failed accumulator before further flight. If there is no 
sign of failure, repeat the inspection thereafter at the applicable 
interval in paragraph (g)(2)(i) or (g)(2)(ii) of this AD. Within 75 
days after the effective date of this AD, replace the affected 
hydraulic accumulator with a new or serviceable accumulator. Doing 
the replacement terminates the repetitive inspections.
    (i) At intervals not to exceed 48 hours.
    (ii) Before further flight following a report of hydraulic fumes 
in the cabin air supply, or after a hydraulic fluid low-level 
warning; and thereafter at intervals not to exceed 48 hours.
    (h) For airplanes on which more than one affected accumulator is 
identified during the inspection required by paragraph (f) of this 
AD: Within 12 days after the effective date of this AD, replace any 
affected accumulator in accordance with paragraph (g)(1) of this AD 
so that no more than one accumulator with an affected S/N remains on 
the airplane; and inspect any remaining accumulator at the 
applicable interval in paragraph (g)(2) of this AD.

    Note 1: BAE Systems (Operations) Limited Service Bulletin 
ISB.29-A046, dated March 14, 2006, refers to APPH Service Bulletin 
AIR91666-29-02, dated March 2006, as an additional source of service 
information for determining if an accumulator is a serviceable 
accumulator. The procedures include disassembling the accumulator 
cylinder, and testing it for cracking.


    Note 2: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Parts Installation

    (i) Except as provided by paragraph (g)(2) of this AD: As of the 
effective date of this AD, no hydraulic accumulator having P/N 
AIR91666-0, -1, or -2 that has an S/N identified in paragraph C of 
the Accomplishment Instructions of BAE Systems (Operations) Limited 
Service Bulletin ISB.29-A046, dated March 14, 2006, may be installed 
on any airplane except for accumulators on which the actions 
specified in the Accomplishment Instructions of APPH Service 
Bulletin AIR91666-29-02, dated March 2006, have been done.

Special Flight Permit Limited

    (j) Using special flight permits (14 CFR 21.197 and 21.199) 
before all affected hydraulic actuators are replaced on the airplane 
is allowed only if the airplane has not flown more than 5 flight 
cycles since the last inspection done in accordance with paragraph 
(g)(2) or (h) of this AD, as applicable; and if the flight can be 
accomplished in one flight cycle with the airplane unpressurized.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, ANM-116, Transport Airplane Directorate, 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

Related Information

    (l) EASA emergency airworthiness directive 2006-0061-E 
[Corrected], dated March 17, 2006, also addresses the subject of 
this AD.

    Issued in Renton, Washington, on July 11, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-11415 Filed 7-18-06; 8:45 am]
BILLING CODE 4910-13-P