Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

[Federal Register Volume 61, Number 135 (Friday, July 12, 1996)]
[Rules and Regulations]
[Pages 36620-36622]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-17533]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-ANE-10; Amendment 39-9676; AD 96-13-08]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Pratt & Whitney (PW) PW4000 series turbofan engines. 
This action requires initial and repetitive inspections of the aft 
cascade support frame assembly of thrust reverser for cracks, and 
replacement, if necessary, with serviceable parts; or lockout of the 
thrust reversers. This amendment is prompted by reports of aft cascade 
support frame assembly failures. The actions specified in this AD are 
intended to prevent aft cascade support frame assembly failure due to 
cracks, which can result in thrust reverser

[[Page 36621]]

hardware liberation and ejection from the aircraft during thrust 
reverser operation, which can contaminate the runway with debris, 
causing an operational hazard to other aircraft during takeoff and 
landing.

DATES: Effective August 1, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 1, 1996.
    Comments for inclusion in the Rules Docket must be received on or 
before September 10, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 96-ANE-10, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be 
submitted to the Rules Docket by using the following Internet address: 
``[email protected]''. All comments must contain the 
Docket No. in the subject line of the comment.
    The service information referenced in this AD may be obtained from 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 
565-6600, fax (860) 565-4503. This information may be examined at the 
FAA, New England Region, Office of the Assistant Chief Counsel, 12 New 
England Executive Park, Burlington, MA; or at the Office of the Federal 
Register 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Chris Gavriel, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7147, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA) 
has received reports of thrust reverser failure on Pratt & Whitney (PW) 
PW4000 series turbofan engines. The thrust reverser aft cascade support 
frame assembly can develop cracks due to high cycle fatigue that could 
propagate to failure. To date, there have been a total of 38 aft 
cascade support frame assemblies that were found either cracked or 
failed. Failure of the cascade support assembly allows thrust reverser 
hardware to be liberated and ejected from the aircraft during thrust 
reverser operation. Seven of the failed assemblies caused liberations 
of thrust reverser hardware. It is possible that other aircrews, either 
departing or arriving on the same runway, may not see debris left on 
the runway after a failure of the thrust reverser aft cascade support 
frame assembly. This debris, therefore, could cause a serious unsafe 
condition for departing and arriving aircraft. This condition, if not 
corrected, could result in aft cascade support frame assembly failure 
due to cracks, which can result in thrust reverser hardware liberation 
and ejection from the aircraft during thrust reverser operation, which 
can contaminate the runway with debris, causing an operational hazard 
to other aircraft during takeoff and landing.
    The FAA has reviewed and approved the technical contents of PW 
Service Bulletin (SB) No. PW4NAC 78-78, Revision 6, dated March 6, 
1996, and SB No. PW4MD11 78-67, Revision 5, dated March 6, 1996, that 
describe procedures for inspection of the aft cascade support frame 
assembly.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same type design, this AD is 
being issued to prevent aft cascade support frame assembly failure. 
This AD requires initial and repetitive inspections of the aft cascade 
support frame assembly for cracks, and replacement, if necessary, with 
serviceable parts; or lockout of the thrust reversers in accordance 
with the applicable Aircraft Maintenance Manual for a time period not 
to exceed 10 days. The actions are required to be accomplished in 
accordance with the SB's described previously.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications should identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-ANE-10.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, 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:

[[Page 36622]]

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec. 39.13  [Amended]

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

96-13-08  Pratt & Whitney: Amendment 39-9676. Docket 96-ANE-10.

    Applicability: Pratt & Whitney (PW) PW4000 series turbofan 
engines, with thrust reverser, Supplemental Type Certificate (STC) 
No. SJ514NE, installed on Airbus A300-600 and A310 series aircraft, 
and thrust reverser, STC No. SE744NE, installed on McDonnell Douglas 
MD-11 series aircraft. These thrust reversers incorporate aft 
cascade support frame assemblies, Part Numbers (P/N's) 221-0516-503 
and 221-0516-504.

    Note: This airworthiness directive (AD) applies to each engine 
with affected thrust reversers identified in the preceding 
applicability provision, regardless of whether it has been modified, 
altered, or repaired in the area subject to the requirements of this 
AD. For engines with affected thrust reversers that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must use the 
authority provided in paragraph (c) to request approval from the 
Federal Aviation Administration (FAA). This approval may address 
either no action, if the current configuration eliminates the unsafe 
condition, or different actions necessary to address the unsafe 
condition described in this AD. Such a request should include an 
assessment of the effect of the changed configuration on the unsafe 
condition addressed by this AD. In no case does the presence of any 
modification, alteration, or repair remove any engine with affected 
thrust reversers from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent aft cascade support frame assembly failure due to 
cracks, which can result in thrust reverser hardware liberation and 
ejection from the aircraft during thrust reverser operation, which 
can contaminate the runway with debris, causing an operational 
hazard to other aircraft during takeoff and landing, accomplish the 
following:
    (a) For engines with affected thrust reversers installed on 
Airbus A300-600 and A310 series aircraft, accomplish the following:
    (1) Initially inspect aft cascade support frame assemblies for 
cracks within 250 flight hours after the effective date of this AD, 
in accordance with the Accomplishment Instructions, Part 1--Interim 
Inspection, of PW Service Bulletin (SB) No. PW4NAC 78-78, Revision 
6, dated March 6, 1996.
    (2) Thereafter, inspect aft cascade support frame assemblies for 
cracks at intervals not to exceed 450 flight hours since the last 
inspection, in accordance with the Accomplishment Instructions, Part 
1--Interim Inspection, of PW SB No. PW4NAC 78-78, Revision 6, dated 
March 6, 1996.
    (3) For aft cascade support frame assemblies that do not meet 
the return to service criteria stated in the Accomplishment 
Instructions, Part 1--Interim Inspection, of PW SB No. PW4NAC 78-78, 
Revision 6, dated March 6, 1996, prior to further flight, accomplish 
either of the following:
    (i) Remove from service cracked aft cascade support frame 
assemblies, and replace with a serviceable part; or
    (ii) Lockout the thrust reverser in accordance with the Airbus 
A300-600 and A310 series Aircraft Maintenance Manuals, as 
applicable, for a time period not to exceed 10 days. At the 
conclusion of the 10-day lockout period, prior to further flight 
remove any cracked aft cascade support frame assemblies and replace 
with serviceable parts.
    (b) For engines with affected thrust reversers installed on 
McDonnell Douglas MD-11 series aircraft, accomplish the following:
    (1) Initially inspect aft cascade support frame assemblies for 
cracks within 250 flight hours after the effective date of this AD, 
in accordance with the Accomplishment Instructions, Part 1--Interim 
Inspection, of PW SB No. PW4MD11 78-67, Revision 5, dated March 6, 
1996.
    (2) Thereafter, inspect aft cascade support frame assemblies for 
cracks at intervals not to exceed 450 flight hours since the last 
inspection, in accordance with the Accomplishment Instructions, Part 
1--Interim Inspection, of PW SB No. PW4MD11 78-67, Revision 5, dated 
March 6, 1996.
    (3) For aft cascade support frame assemblies that do not meet 
the return to service criteria stated in the Accomplishment 
Instructions, Part 1--Interim Inspection, of PW SB No. PW4MD11 78-
67, Revision 5, dated March 6, 1996, prior to further flight, 
accomplish either of the following:
    (i) Remove from service cracked aft cascade support frame 
assemblies, and replace with a serviceable part; or
    (ii) Lockout the thrust reverser in accordance with the 
McDonnell Douglas MD-11 series Aircraft Maintenance Manual, for a 
time period not to exceed 10 days. At the conclusion of the 10-day 
lockout period, prior to further flight remove any cracked aft 
cascade support frame assemblies and replace with serviceable parts.
    (c) 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, Engine Certification Office. The 
request should be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (d) 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 aircraft to a location where 
the requirements of this AD can be accomplished.
    (e) The actions required by this AD shall be done in accordance 
with the following PW SB's:

------------------------------------------------------------------------
          Document No.             Pages    Revision         Date       
------------------------------------------------------------------------
PW4NAC 78-78...................  1........        6   March 6, 1996.    
                                 2,3......        2   October 31, 1995. 
                                 4-6......        6   March 6, 1996.    
                                 7........        5   October 31, 1995. 
                                 8-11.....        6   March 6, 1996.    
                                 12.......        5   October 31, 1995. 
                                 13-19....        6   March 6, 1996.    
                                 20-22....        5   October 31, 1995. 
                                 23-34....        6   March 6, 1996.    
                                 35.......        5   October 31, 1995. 
                                 36, 37...        6   March 6, 1996.    
                                 38.......        5   October 31, 1995. 
                                 39, 40...        6   March 6, 1996.    
Total pages:                     40.......                              
PW4MD11 78-67..................  1-38.....        5   March 6, 1996.    
Total pages:                     38.......                              
------------------------------------------------------------------------

    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 Pratt & Whitney, 400 Main St., 
East Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-
4503. Copies may be inspected at the FAA, New England Region, Office 
of the Assistant Chief Counsel, 12 New England Executive Park, 
Burlington, MA; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on August 1, 1996.

    Issued in Burlington, Massachusetts, on July 2, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 96-17533 Filed 7-11-96; 8:45 am]
BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T05:14:13.259910+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

e30c12715d396115ddcdd2ce211c75aa1aa4b7ee27a923872247bdb089976331

Text SHA-256

5f5b6dbe804e4379cb7726d2a9049e1252123660764550b1ec0e2781199f62c6