AD 2000-22-51

[Federal Register Volume 65, Number 238 (Monday, December 11, 2000)]
[Rules and Regulations]
[Pages 77263-77282]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-31012]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-42-AD; Amendment 39-12034; AD 2000-22-51]
RIN 2120-AA64


Airworthiness Directives; Model HH-1K, TH-1F, TH-1L, UH-1A, UH-
1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida 
Aviation SW204, SW204HP, SW205, and SW205A-1 Helicopters Manufactured 
by Bell Helicopter Textron Inc. for the Armed Forces of the United 
States

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting superseding Airworthiness Directive (AD) 2000-22-51, which was 
sent previously by individual letters to all known U.S. owners and 
operators of Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-
1H, UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, 
SW205, and SW205A-1 helicopters manufactured by Bell Helicopter Textron 
Inc. (BHTI) for the Armed Forces of the United States. This AD requires 
establishing a retirement life for certain main rotor masts, creating a 
component history card or equivalent record, and identifying certain 
masts as unairworthy. This AD also requires removing the hub spring, if 
installed, and determining whether a main rotor mast (mast) has ever 
been installed on a helicopter while operated with a hub spring. 
Conducting certain inspections based on the retirement index number 
(RIN) and on whether the helicopter was ever operated with a hub spring 
is also required. Replacing any mast that has inadequate radius or a 
burr in the damper clamp splined area is also required. Finally, this 
AD requires sending information concerning the mast to the FAA. This 
amendment is prompted by the discovery of a crack in a mast with a 
lower RIN value than the established life limit. This action is 
necessary to preclude the occurrence of a fatigue crack in the damper 
clamp splined area of a mast. This condition, if not corrected, could 
result in failure of a mast or main rotor trunnion (trunnion), 
separation of the main rotor system, and subsequent loss of control of 
the helicopter.

DATES: Effective December 26, 2000, to all persons except those persons 
to whom it was made immediately effective by Emergency AD 2000-22-51, 
issued on November 2, 2000, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before February 9, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2000-SW-42-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: <a href="/cdn-cgi/l/email-protection#6d54400c1e1a400c090e0200000803191e2d0b0c0c430a021b"><span class="__cf_email__" data-cfemail="6b52460a181c460a0f080406060e051f182b0d0a0a450c041d">[email&#160;protected]</span></a>.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aviation Safety 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-
5783.

SUPPLEMENTARY INFORMATION: The FAA issued Emergency AD 2000-08-53 
(Docket No. 2000-SW-08-AD) on April 26, 2000, which superseded AD 89-
17-03, Amendment 39-6251, Docket No. 88-ASW-33 (54 FR 31935, August 3, 
1989), which established RIN counting procedures for the mast 
assemblies installed on H-1 series surplus military helicopters. AD 
2000-08-53 also incorporated life-hour adjustments for mast hub spring 
and helicopter usage. Since issuing AD 2000-08-53, the FAA has issued 
AD 2000-15-21, Amendment 39-11854, Docket 2000-SW-01-AD (65 FR 48605, 
August 9, 2000) to require removing masts, part number (P/N) 204-011-
450-001 and -005, from service. The FAA also issued Emergency AD 2000-
15-52, Docket No. 2000-SW-28-AD, on July 25, 2000, for the BHTI Model 
204B, 205A, 205A-1, 205B, and 212 helicopters, which was prompted by a 
report of another cracked mast, similar to the masts installed on H-1 
series helicopters. Metallurgical inspection revealed that the mast 
cracked as a result of fatigue in snap ring groove radii that were 
smaller than the 0.020-inch minimum allowable dimension. Detailed 
takeoff and lift event data for the entire life of the mast confirm 
that the accumulated RIN count at the time the fatigue crack was 
detected was approximately 68,000 when calculated in accordance with 
the RIN counting procedures in effect at the time of the failure.
    U.S. Army Safety of Flight Message UH-1-10, dated July 19, 2000, 
required inspecting masts for a minimum radius of 0.020 inch or for a 
burr around the

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circumference of the snap ring groove and removing defective masts from 
service. Based on that message and a review of fatigue data and 
previously issued AD's, the FAA has concluded that several corrections 
to the RIN counting procedures are required as follows:
    <bullet> Recalculating the accumulated RIN and revised hours TIS to 
date for certain masts to correct the inadequate factors provided in AD 
2000-08-53. New RIN and frequency of event per hour factors are 
required to calculate the accumulated RIN and revised hours TIS to 
properly reflect the actual level of torque (horsepower rating of 
helicopter) applied to the mast when it is installed on the different 
helicopter models affected by this AD.
    <bullet> Using the new RIN factors for each takeoff and external 
load lift to continue the calculations for the accumulated RIN as 
installed on the different helicopter models affected by this AD and 
changing the definition for external load lift.
    <bullet> Expanding the serial number (S/N) applicability for a one-
time special inspection to detect inadequate radii and burrs in the 
snap ring grooves to include masts with S/N 00000 through 52720, 61433 
through 61444, or 61457 through 61465, regardless of prefix. This 
action was required based on inadequate radius and burrs detected 
outside the S/N applicability of the previous AD.
    <bullet> Reducing the compliance time to 100,000 accumulated RIN 
for any affected mast for a one-time special inspection to detect burrs 
in the snap ring grooves.
    <bullet> Adding a one-time special inspection to detect inadequate 
radii and burrs in the snap ring grooves for any mast that has been 
previously installed with a hub spring.
    Since the unsafe condition described is likely to exist or develop 
on other Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, 
UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, 
and SW205A-1 helicopters manufactured by BHTI for the Armed Forces of 
the United States, the FAA issued Emergency AD 2000-22-51 to prevent 
failure of a mast or trunnion, separation of the main rotor system, and 
subsequent loss of control of the helicopter. The AD requires the 
following:
    <bullet> Within 10 hours TIS, create a component history card or 
equivalent record.
    <bullet> Within 10 hours TIS, determine and record the accumulated 
RIN and revised hours TIS.
    <bullet> Establish a retirement life for any mast, P/N 204-011-450-
007, -105, or -109, and replace any mast that has accumulated 265,000 
RIN or 15,000 or more revised hours TIS and identify the removed mast 
as unairworthy.
    <bullet> Within 25 hours TIS, remove any hub spring.
    <bullet> Determine if the mast has ever been operated with a hub 
spring.
    <bullet> Before reaching 100,000 RIN for a mast that has never been 
on a helicopter operated with a hub spring:
    <bullet> Inspect the upper and lower snap ring groove in the damper 
clamp splined area for an inadequate radius and for a burr.
    <bullet> Remove the mast before exceeding 100,000 RIN if any radius 
is inadequate or before exceeding 170,000 RIN if a burr is found, and 
identify such masts as unairworthy.
    <bullet> Before reaching 100,000 RIN or 400 unfactored flight 
hours, whichever occurs first, on a mast that was installed on a 
helicopter with a hub spring or if the history of a hub spring 
installation is unknown:
    <bullet> Inspect each snap ring groove for an inadequate radius or 
for a burr.
    <bullet> Remove any mast before further flight if any groove radius 
is inadequate or if a burr is found, and identify such masts as 
unairworthy.
    <bullet> After completing the inspections, send the requested 
information to the FAA. The requirements for retirement life hours for 
the trunnion remain the same as required in superseded AD 2000-08-53, 
Docket 2000-SW-08-AD. The short compliance time involved is required 
because the previously described critical unsafe condition can 
adversely affect the structural integrity and controllability of the 
helicopter. Therefore, the actions listed previously are required at 
the specified time intervals, and this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on November 2, 2000, to all known U.S. owners and operators of 
Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, 
and UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, and 
SW205A-1 helicopters manufactured by BHTI for the Armed Forces of the 
United States. These conditions still exist, and the AD is hereby 
published in the Federal Register as an amendment to section 39.13 of 
the Federal Aviation Regulations (14 CFR 39.13) to make it effective to 
all persons.
    The FAA estimates that 75 helicopters of U.S. registry will be 
affected by this AD. It will take approximately 10 work hours per 
helicopter to remove and replace the mast, if necessary; 6 work hours 
to remove any hub spring; and 10 work hours to inspect the mast for 
proper radius or a burr. The approximate time necessary for calculating 
the accumulated RIN and for providing the requested information to the 
FAA is 15 work hours per helicopter. The average labor rate is $60 per 
work hour. Required parts will cost approximately $9,538 to replace a 
mast, if necessary. Based on these figures, the total cost impact of 
the AD on U.S. operators is estimated to be $899,850 ($11,998 per 
helicopter, assuming inspecting 1 mast, removing 1 hub spring, 
replacing 1 mast, determining the RIN calculations, and providing the 
requested information to the FAA).

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 mailed 
comments submitted in response to this rule must submit a self-
addressed, stamped postcard on which the following statement is made:

[[Page 77265]]

``Comments to Docket No. 2000-SW-42-AD.'' The postcard will be date 
stamped and returned to the commenter.
    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it 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 removing Amendment 39-6251 (54 FR 
31935, August 3, 1989) and by adding a new airworthiness directive to 
read as follows:

2000-22-51  Firefly Aviation Helicopter Services (Previously 
Erickson Air-Crane Co.); Garlick Helicopters, Inc.; Hawkins and 
Powers Aviation, Inc.; International Helicopters, Inc.; Tamarack 
Helicopters, Inc. (Previously Ranger Helicopter Services, Inc.); 
Robinson Air Crane, Inc.; Williams Helicopter Corporation 
(Previously Scott Paper Co.); Smith Helicopters; Southern 
Helicopter, Inc.; Southwest Florida Aviation; Arrow Falcon 
Exporters, Inc. (Previously Utah State University); U.S. Helicopter, 
Inc.; and Western International Aviation, Inc.: Amendment 39-12034. 
Docket No. 2000-SW-42-AD. Supersedes Emergency AD 2000-08-53, Docket 
No. 2000-SW-08-AD and AD 89-17-03, Amendment 39-6251, Docket No. 88-
ASW-33.

    Applicability: Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, 
UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida Aviation 
SW204, SW204HP, SW205, and SW205A-1 helicopters, manufactured by 
Bell Helicopter Textron Inc. (BHTI) for the Armed Forces of the 
United States, with main rotor mast (mast), part number (P/N) 204-
011-450-007, -105, or -109, or main rotor trunnion (trunnion), P/N 
204-011-105-001, installed, certificated in any category.

    Note 1: This AD applies to each helicopter identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For helicopters 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 (c) 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.

    Note 2: This AD requires using new factors to recalculate the 
FACTORED flight hours and the accumulated Retirement Index Number 
(RIN) for masts installed on certain helicopter models. This AD also 
expands the serial number (S/N) applicability for the one-time 
special inspection of the mast.

    To prevent failure of a mast or trunnion, separation of the main 
rotor system, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) For the mast, P/N 204-011-450-007, -105, or -109:

    Note 3: The next higher assembly level for the affected P/N's 
are the 204-040-366 mast assemblies. Check the aircraft records for 
the appropriate P/N and assembly level.

    (1) Within 10 hours time-in-service (TIS), create a component 
history card or equivalent record for the mast.
    (2) Within 10 hours TIS, determine and record the accumulated 
RIN and revised hours TIS for the mast as follows:
    (i) Review the aircraft maintenance records for the mast. If the 
helicopter model installation history or hours TIS of the mast is 
unknown, remove the mast from service, identify the mast as 
unairworthy, and replace it with an airworthy mast before further 
flight.
    (ii) Determine the accumulated RIN and the revised hours TIS in 
accordance with the Instructions in Appendix 1. For those hours TIS 
the mast has been installed on a BHTI Model 204B, 205A, 205A-1, 
205B, or 212 helicopter, determine the accumulated RIN in accordance 
with the AD's issued for those helicopters.
    (iii) Record the accumulated RIN and revised hours TIS for the 
mast on the component history card or equivalent record. Use the 
revised hours TIS as the new hours TIS for the mast.
    (3) Before further flight after accomplishing the requirements 
of paragraph (a)(2) of this AD, remove from service any mast that 
has accumulated 265,000 or more RIN or 15,000 or more revised hours 
TIS and identify the mast as unairworthy. Replace the mast with an 
airworthy mast.
    (4) Within 25 hours TIS, remove any hub spring installed on any 
affected helicopter.

    Note 4: U.S. Army Modification Work Order (MWO) 55-1520-242-50-1 
pertains to the removal of the hub spring and replacement of any 
required parts. U.S. Army Safety of Flight Message UH-1-00-10 dated 
July 19, 2000, also pertains to the subject of this AD.

    (5) Determine whether a mast with S/N 00000 through 52720, 61433 
through 61444, or 61457 through 61465 (regardless of prefix), has 
ever been installed on a helicopter while operated with a hub 
spring.
    (i) If a mast has never been installed on a helicopter while 
operated with a hub spring, before reaching 100,000 RIN, inspect the 
upper and lower snap ring grooves in the damper clamp splined area 
for:
    (A) A minimum radius of 0.020 inch around the entire 
circumference (see Figures 1 and 2), using a 100  x  or higher 
magnification. If any snap ring groove radius is less than 0.020 
inch, identify the mast as unairworthy and replace it with an 
airworthy mast before exceeding 100,000 RIN.
    (B) A burr (see Figures 1 through 3), using a 200  x  or higher 
magnification. If a burr is found in any snap ring groove/spline 
intersection, identify the mast as unairworthy and replace it with 
an airworthy mast before exceeding 170,000 RIN.
    (ii) If a mast has ever been installed on a helicopter while 
operated with a hub spring or if the history of a hub spring 
installation is unknown, before reaching 100,000 RIN or 400 
unfactored flight hours, whichever occurs first, inspect the upper 
and lower snap ring grooves in the damper clamp splined area for:
    (A) A minimum radius of 0.020 inch around the entire 
circumference (see Figures 1 and 2), using a 100  x  or higher 
magnification. If any snap ring groove radius is less than 0.020 
inch, identify the mast as unairworthy and replace it with an 
airworthy mast before further flight.
    (B) A burr (see Figures 1 through 3), using a 200  x  or higher 
magnification. If a burr is found in any snap ring groove/spline 
intersection, identify the mast as unairworthy and replace it with 
an airworthy mast before further flight.
    (6) After accomplishing the requirements of paragraph (a)(2) of 
this AD, continue to calculate the accumulated RIN for the mast by 
multiplying all takeoff and external load lifts by the RIN factors 
defined in columns (D) and (G) of Table 1 of Appendix 1 of this AD.

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    (7) After accomplishing the requirements of paragraph (a)(2) of 
this AD, continue to count the hours TIS for the mast. Any hours TIS 
for the mast while installed on a helicopter operated with a hub 
spring or if the history of a hub spring installation is unknown 
must be factored in accordance with the instructions in Appendix 1 
of this AD.
    (8) This AD establishes a retirement life of 265,000 accumulated 
RIN or 15,000 hours TIS, whichever occurs first, for mast, P/N 204-
011-450-007, -105, and -109.
    (9) Within 10 days after completing the inspections required by 
paragraph (a)(5) of this AD, send the information contained on the 
AD compliance inspection report sample format contained in Appendix 
2 to the Manager, Rotorcraft Certification Office, Federal Aviation 
Administration, Fort Worth, Texas 76193-0170, USA. Reporting 
requirements have been approved by the Office of Management and 
Budget and assigned OMB control number 2120-0056.

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    (b) For the trunnion, P/N 204-011-105-001:
    (1) Within 10 days, create a component history card or 
equivalent record for the trunnion and record the hours TIS 
accumulated on the trunnion. If the TIS cannot be determined, enter 
900 hours for each year from the date the trunnion was installed.
    (2) Remove any trunnion with 14,900 or more hours TIS from 
service within the next 100 hours TIS.
    (3) Remove any trunnion with less than 14,900 hours TIS from 
service at or before 15,000 hours TIS.

    Note 5: Paragraph (b) of this AD continues the requirements of 
the superseded AD for the trunnion.

    (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, Rotorcraft Certification Office, 
FAA. Operators shall submit their request through an FAA Principal 
Maintenance Inspector, who may concur or comment and then send it to 
the Manager, Rotorcraft Certification Office.

    Note 6: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Manager, Rotorcraft Certification Office.

    (d) Special flight permits may be issued in accordance with 14 
CFR 21.197 and 21.199 to operate the helicopter to a location where 
the requirements of this AD can be accomplished.
    (e) This amendment becomes effective on December 26, 2000, to 
all persons except those persons to whom it was made immediately 
effective by Emergency AD 2000-22-51, issued November 2, 2000, which 
contained the requirements of this amendment.

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APPENDIX 1
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Appendix 2

Appendix 2 to AD 2000-22-51

AD Compliance Inspection Report (Sample Format) P/N 204-011-450-007/-
105/-109 Main Rotor Mast

    Provide the following information and mail or fax it to: 
Manager, Rotorcraft Certification Office, Federal Aviation 
Administration, Fort Worth, Texas 76193-0170, USA, Fax: 817-222-
5783.
    Aircraft Registration No:
    Helicopter Model:
    Helicopter S/N:
    Mast P/N:
    Mast S/N:
    Mast RIN:
    Mast Total TIS:

Inspection Results

    Were any radii during inspection of this mast determined to be 
less than 0.020 inch?
    If yes, what was the dimension measured?
    Was a burr found in the inspected snap ring grooves?
    Were cracks noted during the inspection?
    Who performed this inspection?
    Provide any other comments?

    Issued in Fort Worth, Texas, on November 30, 2000.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-31012 Filed 12-8-00; 8:45 am]
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