[Federal Register Volume 65, Number 240 (Wednesday, December 13, 2000)]
[Rules and Regulations]
[Pages 77785-77811]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-31628]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-28-AD; Amendment 39-12042; AD 2000-15-52]
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
204B, 205A, 205A-1, 205B, and 212 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: This document publishes in the Federal Register an amendment 
adopting superseding Airworthiness Directive (AD) 2000-15-52, which was 
sent previously to all known U.S. owners and operators of Bell 
Helicopter Textron, Inc. Model (BHTI) Model 204B, 205A, 205A-1, 205B, 
and 212 helicopters by individual letters. This AD reduces the 
retirement index number (RIN) life limit for the main rotor mast 
(mast); increases the RIN factor for masts and main rotor trunnions 
(trunnions); applies standard RIN factors for all external load lifts; 
and requires a one-time inspection of the snap ring groove area of the 
mast. This AD also establishes RIN factors for masts and trunnions that 
have been previously installed on military or restricted category 
helicopters and removes from service those masts that have been 
previously installed with a hub spring. This amendment is prompted by 
an occurrence of a cracked mast at a lower value than the established 
RIN life limit. The actions specified by this AD are intended to 
preclude the occurrence of fatigue

[[Page 77786]]

cracks in the damper clamp splined area of a mast. A crack in the 
damper clamp splined area could result in failure of a mast or 
trunnion, separation of the main rotor system, and subsequent loss of 
control of the helicopter.

DATES: Effective December 28, 2000, to all persons except those persons 
to whom it was made immediately effective by Emergency AD 2000-15-52, 
issued on July 25, 2000, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before February 12, 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-28-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected].

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: On November 13, 1998, the FAA issued AD 98-
24-15 (Amendment 39-10900 (63 FR 64612, November 23, 1998), Docket No. 
97-SW-20-AD. That AD required establishing a RIN tracking system for 
mast and trunnion torque events; creating component history cards or 
equivalent records; converting accumulated factored flight hours to a 
baseline accumulated RIN count; establishing a system for tracking 
increases to the accumulated RIN; and establishing a maximum 
accumulated RIN for certain masts and trunnions. That action was 
prompted by an accident involving a BHTI Model 205A-1 helicopter in 
which a mast failure caused a separation of the main rotor from the 
helicopter. A subsequent metallurgical examination revealed that the 
mast had fractured as a result of fatigue. Analyses and fatigue testing 
conducted by the manufacturer and assessed by the FAA confirmed that 
the remaining lives of the mast and trunnion are more accurately 
assessed by monitoring the number of torque events and flight hours on 
the helicopter rather than by monitoring only flight hours.
    The FAA superseded AD 98-24-15 by issuing Emergency AD 2000-08-52 
(Docket No. 2000-SW-20) on April 21, 2000. AD 2000-08-52 required a 
one-time special inspection for certain serial-numbered masts to detect 
burrs or inadequate radii in the snap ring groove areas that can cause 
fatigue failure. That AD was issued as a result of an accident 
involving a BHTI Model 212 helicopter following in-flight separation of 
its main rotor system. The post-accident investigation revealed a 
fatigue failure in the damper clamp splined area of the mast, part 
number (P/N) 204-011-450-007. Also, operators reported at least five 
other failures in the damper clamp splined area of masts, P/N 204-011-
450-001, -007, and -105, in either the upper or lower snap ring 
grooves. That AD also reduced the maximum allowable RIN life for each 
affected mast and changed the RIN counting procedure to require 
application of a standard RIN factor for all external load lifts 
regardless of altitude change and the type of load lifted. The RIN 
factor assessed for each torque event was increased for masts installed 
on BHTI Model 204B and 205B helicopters. The requirements of AD 98-24-
15 pertaining to trunnions, P/N 204-011-105-001 and -103, were not 
changed by AD 2000-08-52.
    After issuing AD 2000-08-52, the FAA received a report of another 
cracked mast. 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 (1,249) 
and lift (16,339) event data for the entire life of the mast confirmed 
that the accumulated RIN count at the time the fatigue crack was 
detected was approximately 68,000 when calculated in accordance with 
the most recent RIN counting procedure as defined in AD 2000-08-52. The 
FAA concluded that several corrections to the RIN counting procedure 
are required based on a review of the fatigue data and previously 
issued AD's.
    On July 25, 2000, the FAA issued Emergency AD 2000-15-52 for BHTI 
Model 204B, 205A, 205A-1, 205B, and 212 helicopters. That Emergency AD 
reduces the RIN life limit for the mast and trunnion; increases the RIN 
factor for the masts and trunnions; applies standard RIN factors for 
all external load lifts; and requires a one-time inspection of the snap 
ring groove area of the mast. That Emergency AD also establishes RIN 
factors for masts and trunnions that have been previously installed on 
military or restricted category helicopters and removes from service 
those masts that have been previously installed with a hub spring. That 
action was prompted by an occurrence of a cracked mast at a lower value 
than the established RIN life limit. This condition, if not corrected, 
could result in failure of a mast or trunnion, separation of the main 
rotor system, and subsequent loss of control of the helicopter.
    Since the unsafe condition described is likely to exist or develop 
on other BHTI Model 204B, 205A, 205A-1, 205B, and 212 helicopters of 
the same type designs, the FAA issued Emergency AD 2000-15-52 to 
prevent failure of a mast or trunnion, separation of the main rotor 
system, and subsequent loss of control of the helicopter. The AD 
retains the following requirements from previously issued AD 2000-08-
52:
     Reduces the allowable RIN life limit established in AD 98-
24-15 for masts, P/N 204-011-450-001, -007, -105, -113, and -119;
     Increases the RIN factor assessed for each torque event 
for BHTI Model 204B and 205B helicopters;
     Applies a standard RIN factor for all external load lifts 
regardless of altitude change and type of load lifted; and
     Requires a one-time special inspection of certain S/N 
masts for inadequate radii and presence of burrs in the snap ring 
groove areas.
    The Emergency AD differs from AD 2000-08-52 in that it:
     Requires, before further flight, that the accumulated RIN 
for all mast and trunnion history prior to the implementation of RIN 
counting (required by AD 98-24-15) be corrected for inadequate factors 
used to calculate factored hours TIS and to convert factored flight 
hours to accumulated RIN;
     Increases the RIN factor for each takeoff and external 
load lift for masts and trunnions installed on BHTI Model 204B, 205A, 
and 205A-1 helicopters to properly reflect the actual level of torque 
(horsepower rating) applied to the mast when it is installed in these 
helicopter models;
     Expands the requirement for a one-time special inspection 
to detect inadequate radii and burrs in the snap ring grooves to 
include masts with S/N's 00000 through 52720, 61433 through 61444, and 
61457 through 61465, regardless of prefix;
     Establishes RIN factors for masts and trunnions that have 
been previously installed on military helicopters (BHTI-manufactured 
Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1C, UH-1D, UH-1E, UH-1F, 
UH-1G, UH-1H, UH-1L, UH-1M, UH-1N, and UH-1P; and Southwest Florida 
Aviation SW204, SW204HP, SW205, and SW205A-1) and restricted category 
helicopters (Firefly Aviation Helicopter Services (previously Erickson 
Air Crane Co.); Garlick Helicopters, Inc.; Hawkins and Powers Aviation, 
Inc.; International

[[Page 77787]]

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; Utah State 
University; Western International Aviation, Inc.; and U.S. Helicopter, 
Inc.).
     Requires the immediate removal from service of any mast 
that has been previously installed with a hub spring.
    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 previously stated 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 July 25, 2000 to all known U.S. owners and operators of BHTI 
Model 204B, 205A, 205A-1, 205B, and 212 helicopters. 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 147 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; 10 work hours 
to remove and replace the trunnion, if necessary; and 6 work hours to 
inspect the mast for proper radius or a burr. The approximate time 
necessary for calculating the accumulated RIN, revising the 
Airworthiness Limitations section of the maintenance manuals, and 
providing the information requested 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, and 
$5,300 to replace a trunnion, if necessary. Based on these figures, the 
total cost impact of the AD on U.S. operators is estimated to be 
$1,675,506 ($11,398 per helicopter, assuming one inspection, one mast 
replacement, not trunnion replacement, and that the helicopter's 
accumulated RIN is calculated, the maintenance manuals are revised, and 
the requested information is submitted 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: 
``Comments to Docket No. 2000-SW-28-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 39-10900 (63 FR 
64612, November 23, 1998) and by adding a new airworthiness directive 
to read as follows:

2000-15-52  Bell Helicopter Textron Inc.: Amendment 39-12042. Docket 
No. 2000-SW-28-AD. Supersedes Emergency AD 2000-08-52, Docket No. 
2000-SW-20-AD, and AD 98-24-15, Amendment 39-10900, Docket No. 97-
SW-20-AD.

    Applicability: Model 204B, 205A, 205A-1, 205B, and 212 
helicopters, with main rotor mast (mast), part number (P/N) 204-011-
450-001, -007, -105, -113, or -119, or main rotor trunnion 
(trunnion), P/N 204-011-105-001 or -103, 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 (i) 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 has new requirements which must be complied with 
even if AD's

[[Page 77788]]

98-24-15 and 2000-08-52 have already been accomplished. This AD 
requires the recalculation of accumulated mast and trunnion RIN and 
increases the RIN factors for masts and trunnions installed on 
certain helicopter models. This AD also expands the 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) Before further flight, determine the accumulated Retirement 
Index Number (RIN) in accordance with the Instructions in Appendix 1 
of this AD for the mast and Appendix 2 of this AD for the trunnion. 
If the helicopter model installation history or hours time-in-
service (TIS) of the mast or trunnion is unknown, remove the mast or 
trunnion from service and replace it with an airworthy mast or 
trunnion. If the mast has been installed on certain military 
helicopters (BHTI-manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-
1B, UH-1C, UH-1D, UH-1E, UH-1F, UH-1G, UH-1H, UH-1L, UH-1M, UH-1N, 
and UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, or 
SW205A-1) or restricted category helicopters (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; 
Utah State University; Western International Aviation, Inc.; and 
U.S. Helicopter, Inc.) and you cannot verify that hub springs have 
not been installed, remove the mast from service and replace it with 
an airworthy mast.
    (b) Before further flight, replace any mast, P/N 204-011-450-113 
or 119, that has accumulated 240,000 or more RIN with an airworthy 
mast. Before further flight, replace any mast, P/N 204-011-450-001, 
-007, or -105, that has accumulated 265,000 or more RIN with an 
airworthy mast.
    (c) Before further flight, replace any trunnion, P/N 204-011-
105-103, that has accumulated 240,000 or more RIN with an airworthy 
trunnion. Before further flight, replace any trunnion, P/N 204-011-
105-001, that has accumulated 265,000 or more RIN with an airworthy 
trunnion.
    (d) Before reaching 100,000 RIN, inspect the upper and lower 
snap ring grooves in the damper clamp splined area of any mast with 
serial number (S/N) 00000 through 52720, S/N 61433 through 61444, 
and S/N 61457 through S/N 61465 (regardless of prefix) for:
    (1) A minimum radius of 0.020 inches around the entire 
circumference (see Figures 1 through 3), using a 100x or higher 
magnification. If any snap ring groove radius is less than 0.020 
inches, replace the mast with an airworthy mast prior to exceeding 
100,000 RIN.
    (2) A burr, using a 200x or higher magnification. If a burr is 
found in any snap ring groove/spline intersection, replace the mast 
with an airworthy mast prior to exceeding 170,000 RIN.

BILLING CODE 4910-13-U

[[Page 77789]]

[GRAPHIC] [TIFF OMITTED] TR13DE00.000


[[Page 77790]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.001


[[Page 77791]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.002

    (e) 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.
    (f) Continue to calculate the accumulated RIN for the trunnion 
by multiplying all takeoff and external load lifts by the RIN 
factors defined in columns (D) and (G) of Table 1 of Appendix 2 of 
this AD.
    (g) Before further flight, revise the Airworthiness Limitations 
section of the maintenance manuals for the masts and trunnions in 
accordance with Figure 4.

                                                              Mast and Trunnion Life Limits
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Hours TIS life                                       Hours TIS life
                           Mast part No.                                  limit       RIN life limit   Trunnion part No.       limit      RIN life limit
--------------------------------------------------------------------------------------------------------------------------------------------------------
204-011-450-001....................................................           6,000         265,000      204-011-105-001          15,000         265,000
204-011-450-007....................................................          15,000         265,000      204-011-105-103          13,000         240,000
204-011-450-105....................................................          15,000         265,000
204-011-450-113....................................................          13,000         240,000
204-011-450-119....................................................          13,000         240,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (h) Within 10 days after completing the inspections required by 
this AD, provide the information contained on the AD inspection 
report, sample format, contained in Appendix 3 of this AD and send 
it 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.
    (i) 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 requests through an FAA Principal 
Maintenance Inspector, who may concur or comment and then send it to 
the Manager, Rotorcraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Manager, Rotorcraft Certification Office.

    (j) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR

[[Page 77792]]

21.197 and 21.199) to operate the helicopter to a location where the 
requirements of this AD can be accomplished.
    (k) This amendment becomes effective on December 28, 2000, to 
all persons except those persons to whom it was made immediately 
effective by Emergency AD 2000-15-52, issued July 25, 2000, which 
contained the requirements of this amendment.

[[Page 77793]]

APPENDIX 1
[GRAPHIC] [TIFF OMITTED] TR13DE00.003


[[Page 77794]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.004


[[Page 77795]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.005


[[Page 77796]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.006


[[Page 77797]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.007


[[Page 77798]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.008


[[Page 77799]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.009


[[Page 77800]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.010


[[Page 77801]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.011


[[Page 77802]]



APPENDIX 2
[GRAPHIC] [TIFF OMITTED] TR13DE00.012


[[Page 77803]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.013


[[Page 77804]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.014


[[Page 77805]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.015


[[Page 77806]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.016


[[Page 77807]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.017


[[Page 77808]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.018


[[Page 77809]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.019


[[Page 77810]]


[GRAPHIC] [TIFF OMITTED] TR13DE00.020

BILLING CODE 4910-13-U

[[Page 77811]]

Appendix 3--Ad Compliance Inspection Report

P/N 204-011-450-001/-007/-105/-113/-119 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

Operator Name:
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 inches? 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 December 5, 2000.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 00-31628 Filed 12-12-00; 8:45 am]
BILLING CODE 4910-13-U