[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)]
[Rules and Regulations]
[Pages 15378-15381]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8427]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-ANE-36; Amendment 39-9955; AD 97-05-11]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. ALF502 and LF507 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to AlliedSignal Inc. ALF502R series turbofan engines, 
that currently requires initial and repetitive inspections of the oil 
system chip detectors and oil filter bypass valve, and optional 
installation of an improved oil filter bypass valve, to ensure the 
integrity of the reduction gear system and overspeed protection system. 
The optional installation of the improved oil filter bypass valve 
provides terminating action for the oil bypass valve spring compression 
test requirements of the current AD. This amendment requires more 
stringent oil system inspection requirements and expands the applicable 
engine models to include ALF502L and LF507 series turbofan engines. 
This amendment is prompted by power turbine (PT) shaft separations on 
engines that had been inspected in accordance with the current AD. The 
actions specified by this AD are intended to prevent No. 4 and 5 duplex 
bearing failure, which can result in a Stage 4 low pressure turbine 
(LPT) rotor failure, an uncontained engine failure, and damage to the 
aircraft.

DATES: Effective April 16, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 16, 1997. Comments for inclusion in the Rules Docket must be 
received on or before June 2, 1997.

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-36, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain 
the docket number in the subject line.
    The service information referenced in this AD may be obtained from 
AlliedSignal Aerospace, Attn: Data Distribution, M/S 64-3/2101-201, 
P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax 
(602) 365-5577. This information may be examined at the FAA, New 
England Region, Office of the Assistant Chief Counsel, Burlington, MA; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Raymond Vakili, Aerospace Engineer, 
Los Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone 
(310) 627-5262; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: On July 17, 1987, the Federal Aviation 
Administration (FAA) issued airworthiness directive (AD) 87-06-52 
R1, Amendment 39-5688 (52 FR 31979, August 25, 1987), applicable to 
AlliedSignal Inc. (formerly Avco Lycoming Textron) ALF502R series 
turbofan engines, to require initial and repetitive inspections of 
the oil system chip detectors and oil filter bypass valve, and 
optional installation of an improved oil filter bypass valve, to 
ensure the integrity of the reduction gear system and overspeed 
protection system. The optional installation of the improved oil 
filter bypass valve provides terminating action for the repetitive 
oil filter bypass valve spring compression test requirements of the 
AD 87-06-52 R1, Amendment 39-5688. That action was prompted by 
reports of power turbine (PT) overspeed and uncontained PT blade 
failure resulting from reduction gear system decouple and 
inaccurate PT overspeed signal generation. That condition, if not 
corrected, could result in No. 4 and 5 duplex bearing failure, 
which can result in a Stage 4 low pressure turbine (LPT) rotor 
failure, an uncontained engine failure, and damage to the aircraft.

    Since the issuance of that AD, the FAA has received reports of four 
additional failures of the Stage 4 low pressure turbine (LPT) rotor on 
AlliedSignal Inc. ALF502 series turbofan engines. The LPT failures were 
caused by failure of the No. 4 and 5 duplex bearing, causing bearing 
seizure and LPT shaft separation between the two bearings forward of 
the Stage 4 LPT rotor. In one incident the Stage 4 LPT shaft separation 
caused an uncontained rotor failure.
    The FAA has reviewed and approved the technical contents of the 
following AlliedSignal Inc. Service Bulletins (SBs): No. ALF502L 79-
0171, Revision 1, dated November 27, 1996; No. LF507-1F 79-5, Revision 
1, dated November 27, 1996; No. LF507-1H 79-5, Revision 1, dated 
November 27, 1996; and No. ALF502R 79-9, Revision 1, dated November 27, 
1996. These SBs describe procedures for oil system inspection. In 
addition, the FAA has reviewed and approved the technical contents of 
Textron Lycoming SB No. ALF 502R-79-0162 R2, dated September 8, 1987, 
to ensure that portions of the accomplishment instructions paragraph of 
this SB continue to provide the terminating action for the oil filter 
bypass valve compression spring test, which is required by AD 87-06-52 
R1, Amendment 39-5688. Also, the FAA

[[Page 15379]]

has reviewed and approved the technical contents of Avco Lycoming 
Textron SB No. ALF 502R-72-0160, Revision 2, dated May 26, 1987, and 
Revision 1, dated March 23, 1987, that describe procedures for chip 
detector inspections. Finally, the FAA has reviewed and approved the 
technical contents of Avco Lycoming Textron SB No. ALF 502R-79-0162, 
Revision 1, dated May 26, 1987, and Original, dated March 23, 1987, 
that describe procedures of inspection of the oil filter bypass valve.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of this same type design, this AD 
supersedes AD 87-06-52 R1 to require more stringent oil system 
inspection requirements, including inspection of the full flow chip 
detector, oil filter impending bypass button, oil acid number, oil 
color, and oil quantity. The actions are required to be accomplished in 
accordance with the SBs 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-36.'' 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:

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-5688, (52 FR 
31979, August 25, 1987), and by adding a new airworthiness directive, 
Amendment 39-9955, to read as follows:

97-05-11 AlliedSignal Inc.: Amendment 39-9955. Docket 96-ANE-36. 
Supersedes AD 87-06-52 R1, Amendment 39-5688.

    Applicability: AlliedSignal Inc. Model ALF502 and LF507 series 
turbofan engines, installed on but not limited to British Aerospace 
BAe146-100A, BAe146-200A, BAe146-300A, AVRO 146-RJ70A, AVRO 146-
RJ85A, AVRO 146-RJ100A, and Canadair Model CL-600-1A11 series 
aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
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 that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (f) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent No. 4 and 5 duplex bearing failure, which can result 
in a Stage 4 low pressure turbine (LPT) rotor failure, an 
uncontained engine failure, and damage to the aircraft, accomplish 
the following:
    (a) For ALF502R series engines equipped with oil filter bypass 
valve, part number (P/N) 2-303-432-01, accomplish the following:
    (1) Inspect the engine oil filter bypass valve for leakage 
within the next 25 engine hours or 25 flights in service, whichever 
occurs first, from the effective date of this AD, in accordance with 
Avco Lycoming Textron Service Bulletin (SB) No. ALF 502R-79-0160, 
Revision 1, dated March 20, 1987. Prior to further flight, remove 
from service oil filters exhibiting any leakage and replace with 
serviceable parts.
    (2) Thereafter, inspect the oil filter bypass valve for any 
leakage in accordance with Avco Lycoming Textron SB No. ALF 502R-79-
0162, Original, dated March 23, 1987, or Revision 1, dated May 26, 
1987, at intervals not to exceed 50 engine hours or 50 flights in 
service since last inspection, whichever occurs first, and 
accomplish the following:
    (i) Visually inspect engine chip detectors for metal 
contamination as follows:
    (A) Inspect the full flow chip detector for engines installed 
with a full flow chip detector.
    (B) Inspect the chip detectors located in the accessory gearbox, 
Number 2 bearing scavenge line, and Number 4/5 bearing scavenge 
line, for engines without a full flow chip detector installed.
    (ii) For engines with engine chip detectors exhibiting 
Conditions 2 or 3, and for engines with engine chip detectors 
exhibiting Condition 1 where the oil filter bypass indicator is 
extended, prior to further flight, remove oil filter bypass valves 
exhibiting any leakage and replace with a serviceable part.


[[Page 15380]]


    Note 2: Chip detector conditions are described in Avco Lycoming 
Textron SB No. ALF502R-72-0160, Revision 1, dated March 20, 1987, 
Figures 1, 2 and 3.

    (3) At the next engine shop visit, or within 2,500 engine hours 
after the effective date of this AD, whichever occurs first, conduct 
the oil filter bypass valve spring compression force check, in 
accordance with Avco Lycoming Textron SB No. ALF 502R-79-0162, 
Original, dated March 23, 1987. Oil filter bypass valves which do 
not comply with the spring compression force limits contained in 
Avco Lycoming Textron SB No. ALF 502R-79-0162, Original, dated March 
23, 1987, must be removed and replaced with oil filter bypass valve, 
P/N 2-303-432-02. Replacement of oil filter bypass valve, P/N 2-303-
432-01, with the improved oil filter bypass valve, P/N 2-303-432-02, 
constitutes terminating action for inspection requirements of 
paragraphs (a)(1) and (a)(2) of this AD.
    (4) For the purpose of this AD, an engine shop visit is defined 
as engine maintenance that entails any of the following:
    (i) Separation of a major engine flange (lettered or numbered) 
other than flanges mating with major sections of the nacelle 
reverser. Separation of flanges purely for purposes of shipment, 
without subsequent internal maintenance, is not a ``shop visit.''
    (ii) Removal of a disk, hub, or spool.
    (iii) Removal of the fuel nozzles.
    (b) For ALF 502R series engines equipped with the No. 4 and 5 
duplex bearing assembly numbers 2-141-930-01, or 2-141-930-02, or 2-
141-930-03, perform repetitive oil system maintenance and 
inspections in accordance with the intervals and procedures 
described in AlliedSignal Inc. SB No. ALF502R 79-9, Revision 1, 
dated November 27, 1996.
    (c) For ALF502L series engines equipped with the No. 4 and 5 
duplex bearing assembly numbers 2-141-930-01, or 2-141-930-02, or 2-
141-930-03, perform repetitive oil system maintenance and 
inspections in accordance with the intervals and procedures 
described in AlliedSignal Inc. SB No. ALF502L 79-071, Revision 1, 
dated November 27, 1996.
    (d) For LF507-1F series engines equipped with the No. 4 and 5 
duplex bearing assembly numbers 2-141-930-01, or 2-141-930-02, or 2-
141-930-03, perform repetitive oil system maintenance and 
inspections in accordance with the intervals and procedures 
described in AlliedSignal Inc. SB No. LF507-1F-79-5, Revision 1, 
dated November 27, 1996.
    (e) For LF507-1H series engines equipped with the No. 4 and 5 
duplex bearing assembly numbers 2-141-930-01, or 2-141-930-02, or 2-
141-930-03, perform repetitive oil system maintenance and 
inspections in accordance with the intervals and procedures 
described in AlliedSignal Inc. SB No. LF507-1H-79-5, Revision 1, 
dated November 27, 1996.
    (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, Los Angeles Aircraft 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, Los Angeles Aircraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Los Angeles Aircraft Certification 
Office.

    (g) Special flight permits may be issued in accordance with 
Secs. 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 
inspection requirements of this AD can be accomplished.
    (h) The actions required by this AD shall be done in accordance 
with the accomplishment instructions paragraphs of the following 
documents:

----------------------------------------------------------------------------------------------------------------
         Document No.                    Pages                 Revision                       Date              
----------------------------------------------------------------------------------------------------------------
 Avco Lycoming Textron SB No.   1-7...................  2.....................  May 26, 1987.                   
 ALF 502R-72-0160.                                                                                              
    Total Pages: 7.                                                                                             
Avco Lycoming Textron SB No.    1-7...................  1.....................  March 23, 1987.                 
 ALF 502R-72-0160.                                                                                              
    Total Pages: 7.                                                                                             
Avco Lycoming Textron SB No.    1-5...................  2.....................  September 8, 1987.              
 ALF 502R-79-0162.                                                                                              
    Total Pages: 5.                                                                                             
Avco Lycoming Textron SB No.    1-4...................  1.....................  May 26, 1987.                   
 ALF 502R-79-0162.                                                                                              
    Total Pages: 4.                                                                                             
Avco Lycoming Textron SB No.    1-6...................  Original..............  March 23, 1987.                 
 ALF 502R-79-0162.                                                                                              
    Total Pages: 6.                                                                                             
AlliedSignal Inc. SB No.        1.....................  1.....................  November 27, 1996.              
 ALF502R 79-9.                                                                                                  
                                2.....................  Original..............  June 29, 1995.                  
                                3-7...................  1.....................  November 27, 1996.              
                                8.....................  Original..............  June 29, 1995.                  
                                9-12..................  1.....................  November 27, 1996.              
                                13,14.................  Original..............  June 29, 1995.                  
    Total Pages: 14.                                                                                            
AlliedSignal Inc. SB No. LF507-                                                                                 
 1F.                                                                                                            
  79-5                          1.....................  1.....................  November 27, 1996.              
                                2.....................  Original..............  June 29, 1995.                  
                                3-7...................  1.....................  November 27, 1996.              
                                8.....................  Original..............  June 29, 1995.                  
                                9-12..................  1.....................  November 27, 1996.              
                                13,14.................  Original..............  June 29, 1995.                  
    Total Pages: 14.                                                                                            
AlliedSignal Inc. SB No. LF507- 1.....................  1.....................  November 27, 1996.              
 1H 79-5.                                                                                                       
                                2.....................  Original..............  June 29, 1995.                  
                                3-7...................  1.....................  November 27, 1996.              
                                8.....................  Original..............  June 29, 1995.                  
                                9-12..................  1.....................  November 27, 1996.              
                                13,14.................  Original..............  June 29, 1995.                  
    Total Pages: 14.                                                                                            
AlliedSignal Inc. SB ALF502L    1.....................  1.....................  November 27, 1996.              
 79-0171.                                                                                                       
                                2.....................  Original..............  November 3, 1995.               
                                3-7...................  1.....................  November 27, 1996.              
                                8.....................  Original..............  November 3, 1995.               
                                9-12..................  1.....................  November 27, 1996.              
                                13,14.................  Original..............  November 3, 1995.               
    Total Pages: 14.                                                                                            
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[[Page 15381]]

    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 AlliedSignal Aerospace, Attn: Data 
Distribution, M/S 64-3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-
9003; telephone (602) 365-2493, fax (602) 365-5577. 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.
    (i) This amendment becomes effective on April 16, 1997.

    Issued in Burlington, MA, on March 27, 1997.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 97-8427 Filed 3-28-97; 3:15 pm]
BILLING CODE 4910-13-U