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Published 1999-02-03 · Federal Register document 99-2474

Airworthiness Directives; Textron Lycoming Model O-540-F1B5 Reciprocating Engines

Publication summary

This amendment adopts a new airworthiness directive (AD) that is applicable to Textron Lycoming Model O-540-F1B5 reciprocating engines. This action requires the removal and replacement of the crankshaft gear retaining bolts. This amendment is prompted by 2 reported failures of the crankshaft gear retaining bolts. The actions specified in this AD are intended to prevent failure of the crankshaft gear retaining bolts, which can result in engine failure and subsequent autorotation and forced landing.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:22:57.343810+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_1999-e9a7378e7e7d30d5
Source row
results[52]
Raw source SHA-256
e9a7378e7e7d30d51578560dc0677c56bb1fef0a9323224e2a0afe1544919217

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
99-03-05
Effective date printed in this edition
1999-02-18

Some source clauses remain unstructured. Read the complete publication for conditions that have not been interpreted here.

Read 2 complete recorded clauses
Applicability wording · Applicability
    Applicability: Textron Lycoming Model O-540-F1B5 reciprocating 
engines, with the following Textron Lycoming Engine Serial Numbers, 
installed on but not limited to Robinson Helicopters Co. Model R-44 
rotorcraft.

L-24545-40A        L-24628-40A
L-24766-40A        L-24772-40A
L-25050-40A        L-25052-40A
L-25053-40A        L-25054-40A
L-25063-40A        L-25064-40A
L-25065-40A        L-25066-40A
L-25067-40A        L-25068-40A
L-25069-40A        L-25070-40A
L-25071-40A        L-25072-40A
L-25073-40A        L-25074-40A
L-25075-40A        L-25076-40A
L-25077-40A        L-25078-40A
L-25080-40A        L-25081-40A
L-25083-40A        L-25084-40A
L-25085-40A        L-25086-40A
L-25087-40A        L-25088-40A
L-25089-40A        L-25090-40A
L-25091-40A        L-25092-40A
L-25093-40A        L-25094-40A
L-25095-40A        L-25096-40A
L-25097-40A        L-25098-40A
L-25099-40A        L-25100-40A
L-25101-40A        L-25102-40A
L-25103-40A        L-25104-40A
L-25105-40A        L-25106-40A
L-25116-40A        L-25117-40A
L-25118-40A        L-25119-40A
L-25120-40A        L-25121-40A
L-25122-40A        L-25123-40A
L-25124-40A        L-25125-40A
L-25126-40A        L-25127-40A
L-25128-40A        L-25129-40A
L-25130-40A        L-25131-40A
L-25132-40A        L-25133-40A
L-25134-40A        L-25135-40A
L-25136-40A        L-25137-40A
L-25138-40A        L-25139-40A
L-25140-40A        L-25141-40A
L-25142-40A        L-25143-40A
L-25144-40A        L-25145-40A
L-25146-40A        L-25149-40A
L-25150-40A        L-25154-40A
L-25155-40A        L-25156-40A
L-25157-40A        L-25158-40A
L-25159-40A        L-25160-40A
L-25161-40A        L-25162-40A
L-25164-40A        L-25166-40A
L-25167-40A        L-25168-40A
L-25169-40A        L-25170-40A
L-25171-40A        L-25172-40A
L-25173-40A        L-25174-40A
L-25175-40A        L-25176-40A
L-25177-40A        L-25178-40A
L-25179-40A        L-25180-40A
L-25181-40A        L-25182-40A
L-25183-40A        L-25184-40A
L-25185-40A        L-25186-40A
L-25188-40A        L-25189-40A
L-25190-40A        L-25191-40A
L-25192-40A        L-25193-40A
L-25198-40A        L-25200-40A
L-25201-40A        L-25202-40A
L-25204-40A        L-25206-40A
L-25207-40A        L-25208-40A
L-25211-40A        L-25212-40A
L-25213-40A        L-25214-40A
L-25216-40A        L-25217-40A
L-25218-40A        L-25219-40A
L-25221-40A        L-25222-40A
L-25223-40A        L-25228-40A
L-25229-40A        L-25230-40A
L-25231-40A        L-25232-40A
L-25233-40A        L-25234-40A
L-25235-40A        L-25236-40A
L-25237-40A        L-25238-40A
L-25239-40A        L-25240-40A
L-25242-40A        L-25243-40A
L-25244-40A        L-25246-40A
L-25249-40A        L-25250-40A
L-25251-40A        L-25252-40A
L-25257-40A

    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 (b) 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.

Exact source excerpt. Text positions 8892–12373, end exclusive, in the original decoded publication. SHA-256: 5326d25e79e180e73449aef06865fbf5fcf05a12a7dbd807310210dd6a8bd002

Compliance and requirements
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the crankshaft gear retaining bolts, which 
can result in engine failure and subsequent autorotation and forced 
landing, accomplish the following:
    (a) Within 10 hours time in service, or 3 days after the 
effective date of this AD, whichever occurs first, have the 
crankshaft gear retaining bolt, part number STD-2209, replaced by 
Textron Lycoming or Robinson Helicopter Company.
    (b) 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, New York Aircraft Certification 
Office. Operators shall submit their requests through an appropriate 
FAA Principal Maintenance Inspector, who may add comments and then 
send it to the Manager, New York Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the New York Aircraft Certification 
Office.

    (c) 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.
    (d) This amendment becomes effective on February 18, 1999.

Exact source excerpt. Text positions 12373–13781, end exclusive, in the original decoded publication. SHA-256: 65e4613d6585dba7a25f0b335bdf9e45a8aa5fcca2021368b9d1083861802df1

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 99-03-05 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: a2412eabe8b0333c3efb1755169098d5e1f80aa0b3fa6a1fc2eaacd5fa88a6a2. Source manifest: 87e26990eb8e26eee4c66664079b6955756bf605a96a8ae690a4c04bf8ba2f9d.

Official source · 1999-02-03

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 64, Number 22 (Wednesday, February 3, 1999)]
[Rules and Regulations]
[Pages 5149-5150]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-2474]



========================================================================
Rules and Regulations
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
to and codified in the Code of Federal Regulations, which is published 
under 50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. 
Prices of new books are listed in the first FEDERAL REGISTER issue of each 
week.

========================================================================


Federal Register / Vol. 64, No. 22 / Wednesday, February 3, 1999 / 
Rules and Regulations

[[Page 5149]]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-73-AD; Amendment 39-11019; AD 99-03-05]
RIN 2120-AA64


Airworthiness Directives; Textron Lycoming Model O-540-F1B5 
Reciprocating 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 Textron Lycoming Model O-540-F1B5 reciprocating 
engines. This action requires the removal and replacement of the 
crankshaft gear retaining bolts. This amendment is prompted by 2 
reported failures of the crankshaft gear retaining bolts. The actions 
specified in this AD are intended to prevent failure of the crankshaft 
gear retaining bolts, which can result in engine failure and subsequent 
autorotation and forced landing.

DATES: Effective February 18, 1999.
    Comments for inclusion in the Rules Docket must be received on or 
before April 5, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-73-AD, 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.
    Information regarding this AD may be examined at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Rocco Viselli, Aerospace Engineer, New 
York Aircraft Certification Office, FAA, Engine and Propeller 
Directorate, 10 Fifth St., 3rd Floor, Valley Stream, NY 11581-1200; 
telephone (516) 256-7531, fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA) 
has received reports of 2 failures of the crankshaft gear retaining 
bolts on Textron Lycoming Model O-540-F1B5 reciprocating engines, 
installed on Robinson R44 series rotorcraft. The investigation revealed 
that the head of the retaining bolts sheared off allowing the 
crankshaft gear to disengage. The crankshaft gear drives both magnetos 
and the camshaft. Failure of the retaining bolt results in total loss 
of power without prior warning. The FAA has determined that the 2 
crankshaft gear bolts to fail in service failed from a condition known 
as hydrogen embrittlement. This condition results from the underbaking 
process during manufacturing, which leads to incomplete hydrogen 
relief, and as such, the bolts can be susceptible to hydrogen 
embrittlement. Therefore, the FAA has determined that this condition 
affects only a specific population of retaining bolts, and has 
identified by serial number the specific engines that require 
replacement of the suspect bolts. This condition, if not corrected, 
could result in failure of the crankshaft gear retaining bolts, which 
can result in engine failure and subsequent autorotation and forced 
landing.
    The suspect crankshaft gear retaining bolts must be replaced by 
either Textron Lycoming or Robinson Helicopter company maintenance 
personnel. In order to allow the removal and replacement of the suspect 
bolts without removing the engine from the helicopter, a complex 
procedure is required. This procedure requires removal of the accessory 
gear case without removal of the oil sump, which is beyond the scope of 
current engine service instructions.
    Since an unsafe condition has been identified that is likely to 
exist or develop on engines of the same type design, this AD is being 
issued to prevent crankshaft gear retaining bolt failure. This AD 
requires removal and replacement of the crankshaft gear retaining 
bolts. The actions are required to be accomplished in accordance with 
the service documents 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 98-ANE-73-AD.'' 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

[[Page 5150]]

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, 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

99-03-05  Textron Lycoming: Amendment 39-11019. Docket 98-ANE-73-AD.

    Applicability: Textron Lycoming Model O-540-F1B5 reciprocating 
engines, with the following Textron Lycoming Engine Serial Numbers, 
installed on but not limited to Robinson Helicopters Co. Model R-44 
rotorcraft.

L-24545-40A        L-24628-40A
L-24766-40A        L-24772-40A
L-25050-40A        L-25052-40A
L-25053-40A        L-25054-40A
L-25063-40A        L-25064-40A
L-25065-40A        L-25066-40A
L-25067-40A        L-25068-40A
L-25069-40A        L-25070-40A
L-25071-40A        L-25072-40A
L-25073-40A        L-25074-40A
L-25075-40A        L-25076-40A
L-25077-40A        L-25078-40A
L-25080-40A        L-25081-40A
L-25083-40A        L-25084-40A
L-25085-40A        L-25086-40A
L-25087-40A        L-25088-40A
L-25089-40A        L-25090-40A
L-25091-40A        L-25092-40A
L-25093-40A        L-25094-40A
L-25095-40A        L-25096-40A
L-25097-40A        L-25098-40A
L-25099-40A        L-25100-40A
L-25101-40A        L-25102-40A
L-25103-40A        L-25104-40A
L-25105-40A        L-25106-40A
L-25116-40A        L-25117-40A
L-25118-40A        L-25119-40A
L-25120-40A        L-25121-40A
L-25122-40A        L-25123-40A
L-25124-40A        L-25125-40A
L-25126-40A        L-25127-40A
L-25128-40A        L-25129-40A
L-25130-40A        L-25131-40A
L-25132-40A        L-25133-40A
L-25134-40A        L-25135-40A
L-25136-40A        L-25137-40A
L-25138-40A        L-25139-40A
L-25140-40A        L-25141-40A
L-25142-40A        L-25143-40A
L-25144-40A        L-25145-40A
L-25146-40A        L-25149-40A
L-25150-40A        L-25154-40A
L-25155-40A        L-25156-40A
L-25157-40A        L-25158-40A
L-25159-40A        L-25160-40A
L-25161-40A        L-25162-40A
L-25164-40A        L-25166-40A
L-25167-40A        L-25168-40A
L-25169-40A        L-25170-40A
L-25171-40A        L-25172-40A
L-25173-40A        L-25174-40A
L-25175-40A        L-25176-40A
L-25177-40A        L-25178-40A
L-25179-40A        L-25180-40A
L-25181-40A        L-25182-40A
L-25183-40A        L-25184-40A
L-25185-40A        L-25186-40A
L-25188-40A        L-25189-40A
L-25190-40A        L-25191-40A
L-25192-40A        L-25193-40A
L-25198-40A        L-25200-40A
L-25201-40A        L-25202-40A
L-25204-40A        L-25206-40A
L-25207-40A        L-25208-40A
L-25211-40A        L-25212-40A
L-25213-40A        L-25214-40A
L-25216-40A        L-25217-40A
L-25218-40A        L-25219-40A
L-25221-40A        L-25222-40A
L-25223-40A        L-25228-40A
L-25229-40A        L-25230-40A
L-25231-40A        L-25232-40A
L-25233-40A        L-25234-40A
L-25235-40A        L-25236-40A
L-25237-40A        L-25238-40A
L-25239-40A        L-25240-40A
L-25242-40A        L-25243-40A
L-25244-40A        L-25246-40A
L-25249-40A        L-25250-40A
L-25251-40A        L-25252-40A
L-25257-40A

    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 (b) 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 failure of the crankshaft gear retaining bolts, which 
can result in engine failure and subsequent autorotation and forced 
landing, accomplish the following:
    (a) Within 10 hours time in service, or 3 days after the 
effective date of this AD, whichever occurs first, have the 
crankshaft gear retaining bolt, part number STD-2209, replaced by 
Textron Lycoming or Robinson Helicopter Company.
    (b) 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, New York Aircraft Certification 
Office. Operators shall submit their requests through an appropriate 
FAA Principal Maintenance Inspector, who may add comments and then 
send it to the Manager, New York Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the New York Aircraft Certification 
Office.

    (c) 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.
    (d) This amendment becomes effective on February 18, 1999.

    Issued in Burlington, Massachusetts, on January 27, 1999.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 99-2474 Filed 2-2-99; 8:45 am]
BILLING CODE 4910-13-P


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These are dated publication metadata, recorded clauses and literal source observations. Word, model-label, header and reference matches do not establish current legal effect, manufacturer/model identity, aircraft applicability, installed configuration or compliance.

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