AD 98-24-15

This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron Model 204B, 205A, 205A-1, and 212 helicopters, that currently establishes a retirement life for the main rotor masts (masts) and main rotor trunnions (trunnions) based on time-in-service (TIS) and types of operations. This amendment adds Model 205B helicopters to the applicability; requires creation of component history cards or equivalent records using a Retirement Index Number (RIN) system; establishes a system for tracking increases to the accumulated RIN; and establishes a maximum accumulated RIN for certain masts and trunnions. This amendment is prompted by an accident involving a Model 205A-1 helicopter, in which a mast failure caused a separation of the main rotor from the helicopter. The actions specified by this AD are intended to prevent fatigue failure of the mast or trunnion and subsequent loss of control of the helicopter.

Final rule; request for comments

98-24-15 BELL HELICOPTER TEXTRON: Amendment 39-10900. Docket No. 97-SW-20-AD. Supersedes AD 89-02-07, Amendment 39-6112, Docket No. 87-ASW-63; AD 89-02-07 R1, Amendment 39-6339, Docket No. 87-ASW-63; and priority letter AD 97-14-12, Docket No. 97-SW-20-AD.

Applicability: Model 204B, 205A, 205A-1, 205B, and 212 helicopters, certificated in any category.

NOTE 1: This AD applies to each helicopter 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 helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (e) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required before further flight, unless accomplished previously.

To prevent fatigue failure of the main rotor mast (mast) or main rotor trunnion (trunnion), and subsequent loss of control of the helicopter, accomplish the following:

(a) For Model 204B helicopters:

(1) Create component history cards or equivalent records for the mast, part number (P/N) 204-011-450-001, -007, or -105 and trunnion, P/N 204-011-105-001.

(2) Determine and record on the component history cards or equivalent records the accumulated RIN to-date on the mast and trunnion as follows:

(i) For mast, P/N 204-011-450-001, multiply the total time-in-service (TIS) on the mast to-date by 50 (if result contains a decimal point, round-off to the next higher whole number).

(ii) For mast, P/N 204-011-450-007 or -105, and trunnion, P/N 204-011-105-001, multiply the total TIS on the part to-date by 20 (if the result contains a decimal point, round-off to the next higher whole number).

(3) After complying with paragraphs (a)(1) and (a)(2) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs that were performed. At the end of each day's operations, increase the accumulated RIN on the component history cards or equivalent records as follows:

(i) Increase the RIN by 1 for each takeoff.

(ii) Increase the RIN by 1 for each external load lift, or increase the RIN by 2 for each external load lift operation in which the load is picked up at one elevation and released at another elevation, and the difference in elevation between the pickup point and the release point is 200 feet or greater.(4) Remove the mast, P/N 204-011-450-001, on or before attaining 6,000 hours TIS, or an accumulated RIN of 300,000, whichever occurs first.

(5) Remove the mast, P/N 204-011-450-007 or -105, or trunnion, P/N 204-011-105-001, on or before attaining 15,000 hours TIS, or an accumulated RIN of 300,000, whichever occurs first.

(b) For Model 205A and 205A-1 helicopters:

(1) Create component history cards or equivalent records for the mast, part numbers (P/N) 204-011-450-007, or -105 and trunnion, P/N 204-011-105-001.

(2) Determine and record on the component history cards or equivalent records the accumulated RIN to-date on the mast and trunnion. For mast, P/N 204-011-450-007 or -105, and trunnion, P/N 204-011-105-001, multiply the factored flight hour total to-date, determined in accordance with paragraphs 1, 2, or 3 of the Accomplishment Instructions of Bell Helicopter Textron Alert Service Bulletin No. 205-90-40, Revision A, dated March 21, 1991, by 20 (if theresult contains a decimal point, round-off to the next higher whole number).

(3) After complying with paragraphs (b)(1) and (b)(2) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs that were performed. At the end of each day's operations, increase the accumulated RIN on the component history cards or equivalent records as follows:

(i) Increase the RIN by 2 for each takeoff performed.

(ii) Increase the RIN by 2 for each external load lift, or increase the RIN by 4 for each external load lift operation in which the load is picked up at one elevation and released at another elevation, and the difference in the elevation between the pickup point and the release point is 200 feet or greater.

(4) Remove the mast, P/N 204-011-450-007 or -105, or trunnion, P/N 204-011-105-001, on or before attaining 15,000 hours TIS, or an accumulated RIN of 300,000, whichever occurs first.

(c)For Model 205B helicopters:

(1) Create component history cards or equivalent records for the mast, P/N 204-011-450-007, or -105 and trunnion, P/N 204-011-105-001.

(2) Determine and record on the component history cards or equivalent records the accumulated RIN to-date on the mast and trunnion. For mast, P/N 204-011-450-007 or -105, and trunnion, P/N 204-011-105-001, multiply the factored flight hour total to-date, determined in accordance with paragraph 1, 2, or 3 of the Accomplishment Instructions of Bell Helicopter Textron Alert Service Bulletin No. 205B-90-1, Revision A, dated March 21, 1991, by 20 (if the result contains a decimal point, round-off to the next higher whole number).

(3) After complying with paragraphs (c)(1) and (c)(2) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs performed, and at the end of each day's operations, increase the accumulated RIN on the component history card as follows:

(i) Increase the RIN by 5 for each takeoff performed.

(ii) Increase the RIN by 5 for each external load lift, or increase the RIN by 10 for each external load lift in which the load is picked up at one elevation and released at another elevation, and the difference in the elevation between the pickup point and the release point is 200 feet or greater.

(4) Remove the mast, P/N 204-011-450-007 or -105, or trunnion, P/N 204-011-105-001, on or before attaining 15,000 hours TIS, or an accumulated RIN of 300,000, whichever occurs first.

(d) For Model 212 helicopters:

(1) Create component history cards or equivalent records for the mast, P/N 204-011-450-007, -105, -113, or -119 and trunnion, P/N 204-011-105-001 or -103.

(2) Determine and record on the component history card or an equivalent record the accumulated RIN to-date on the mast and trunnion as follows:

(i) For mast, P/N 204-011-450-007 or -105, and trunnion, P/N 204-011-105-001, multiply the factored flight hour total to-date, determined in accordance with paragraphs 1, 2, and 3 of the Accomplishment Instructions of Bell Helicopter Textron Alert Service Bulletin No. 212-90-64, Revision B, dated March 11, 1992, by 20 (if the result contains a decimal point, round-off to the next higher whole number).

(ii) For mast, P/N 204-011-450-113 or -119, and trunnion, P/N 204-011-105-103, multiply the factored flight hour total to-date, determined in accordance with paragraphs 1, 2, or 3 of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. 212-90-64, Revision B, dated March 11, 1992, by 21.2 (if the result contains a decimal point, round-off to the next higher whole number).

(3) After complying with paragraphs (d)(1) and (d)(2) of this AD, during each operation thereafter, maintain a count of the number and type of external load lifts and the number of takeoffs performed. At the end of each day's operations, increase the accumulated RIN on the component history cards or equivalent records as follows:

(i) Increase the RIN by 5 for each takeoff performed.

(ii) Increase the RIN by 5 for each external load lift, or increase the RIN by 10 for each external load lift in which the load is picked up at one elevation and released at another elevation, and the difference in the elevation between the pickup point and the release point is 200 feet or greater.

(4) Remove the mast, P/N 204-011-450-007 or -105, or trunnion, P/N 204-011-105-001, on or before attaining 15,000 hours TIS, or an accumulated RIN of 300,000, whichever occurs first.

(5) Remove the mast, P/N 204-011-450-113 or -119, or trunnion, P/N 204-011-105-103, on or before attaining 13,000 hours TIS or an accumulated RIN of 275,000, whichever occurs first.

(e) 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 Standards Staff, Rotorcraft Directorate, 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 Standards Staff.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff.

(f) 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 helicopter to a location where the requirements of this AD can be accomplished.

(g) This AD revises the Airworthiness Limitations sections of the maintenance manuals by establishing a new retirement life for the affected masts and trunnions as follows:

P/N 204-011-450-001 -- 6,000 hours TIS or 300,000 RIN whichever occurs first.

P/N 204-011-450-007 or P/N 204-011-450-105 -- 15,000 hours TIS or 300,000 RIN, whichever occurs first.
Masts:
P/N 204-011-450-113 or P/N 204-011-450-119 -- 13,000 hours TIS or 275,000 RIN, whichever occurs first.

P/N 204-011-105-001 -- 15,000 hours TIS or 300,000 RIN, whichever occurs first.
Trunnions:
P/N 204-011-105-103 -- 13,000 hours TIS or 275,000 RIN, whichever occurs first.

(h) The actions shall be done in accordance with:

Bell Helicopter Textron Alert Service Bulletin No. 205-90-40, Revision A, dated March 21, 1991, which is applicable to Model 205A and 205A-1 helicopters;

Bell Helicopter Textron Alert Service Bulletin No. 205B-90-1, Revision A, dated March 21, 1991, which is applicable to Model 205B helicopters; and

Bell Helicopter Textron Alert Service Bulletin No. 212-90-64, Revision B, dated March 11, 1992, which is applicable to Model 212 helicopters.

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 Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, telephone (817) 280-3391, fax (817) 280-6466. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(i) This amendment becomes effective on December 8, 1998.

On December 28, 1988, the FAA issued AD 89-02-07, Amendment 39-6112 (54 FR 1338, January 13, 1989) and on September 19, 1989, issued revised AD 89-02-07 R1, Amendment 39-6339 (54 FR 40381, October 2, 1989), to establish a retirement life for certain masts and trunnions based on TIS and types of operations. Those actions were prompted by results of fatigue stress tests and fatigue analysis of the mast and trunnion under ground-air-ground (GAG) and repeated heavy lift (RHL) loading conditions. On June 27, 1997, the FAA issued priority letter AD 97-14-12 to supersede AD 89-02-07 as revised by AD 89-02-07 R1 to establish retirement lives for certain masts and trunnions that utilize a Retirement Index Number (RIN) system. Exceeding the retirement life of the mast or trunnion could result in fatigue failure of the mast or trunnion and subsequent loss of control of the helicopter.

Since the issuance of AD 89-02-07 and AD 89-02-07 R1, the manufacturer has issued the following service bulletins to establish retirement lives for certain masts and trunnions:

Bell Helicopter Textron Alert Service Bulletin No. 205-90-40, Revision A, dated March 21, 1991, which is applicable to Model 205A-1 helicopters;
Bell Helicopter Textron Alert Service Bulletin No. 205B-90-1, Revision A, dated March 21, 1991, which is applicable to Model 205B helicopters; and
Bell Helicopter Textron Alert Service Bulletin No. 212-90-64, Revision B, dated March 11, 1992, which is applicable to Model 212 helicopters.

Also, since the issuance of the earlier AD s, there has been one accident involving a Model 205A-1 helicopter, in which a mast failure caused a separation of the main rotor from the helicopter. The helicopter, which had been utilized in external load lift operations, was performing an external load lift operation at the time of the accident. A subsequent metallurgical examination revealed that the mast had fractured as a result of fatigue.Analyses and fatigue testing has confirmed that the retirement lives of the mast and trunnion are more accurately assessed by monitoring the number of torque events and time-in-service (TIS) incurred by the helicopter rather than by monitoring only TIS. Exceeding the retirement life of the mast or trunnion could result in fatigue failure of the mast or trunnion and subsequent loss of control of the helicopter. Additionally, the FAA has determined that Model 205B helicopters should be added to the applicability.

Since an unsafe condition has been identified that is likely to exist or develop on other Model 204B, 205A, 205A-1, 205B, and 212 helicopters of the same type design, this AD supersedes AD 89-02-07 as revised by AD 89-02-07 R1 and AD 97-14-12 to require, before further flight, creation of component history cards or equivalent records using a RIN system for certain masts and trunnions; to establish a system for tracking increases to the accumulated RIN; and to establish retirement lives for the mast and trunnion for each of the affected model helicopters. The actions are required to be accomplished in accordance with the service bulletins described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity of the aircraft. Therefore, the actions are required before further flight, and this AD must be issued immediately.

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 rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 97-SW-20-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 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 thatit 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 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]
2. Section 39.13 is amended by removing Amendment 39-6112 (54 FR 1338, January 13, 1989), Amendment 39-6339 (54 FR 40381, October 2, 1989) and by adding a new airworthiness directive (AD), Amendment 39-10900, to read as follows: