AD 2000-25-03

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Inc. (BHTI) Model 205A-1, 205B, 212, 412, and 412CF helicopters. This action requires inspecting the locking washer on each main rotor actuator (actuator) for twisting or damage to the tab and replacing any locking washer that has a twisted or damaged tab. Replacing certain locking washers, regardless of condition, is also required within a specified time period. Installing a certain airworthy locking device on each actuator constitutes terminating action for the requirements of this AD. This amendment is prompted by an incident in which a damaged locking washer allowed the rod end to detach from the collective actuator, causing loss of collective control of the main rotor. The current locking washer is subject to mechanical damage and failure, which allows the actuator piston to unthread itself from its rod end. This condition, if not corrected, could cause loss of control of the main rotor and subsequent loss of control of the helicopter.

Final rule; request for comments

2000-25-03 BELL HELICOPTER TEXTRON INC.: Amendment 39-12037. Docket No. 2000- SW-49-AD.
Applicability:
(a) Model 205A-1 helicopters with a hydraulic servo actuator (actuator), part number (P/N) 41105950, serial numbers with an "HR" prefix up to and including 490, installed, certificated in any category; and

(b) Model 205A-1, 205B, 212, 412, and 412CF helicopters with an actuator, P/N 41000470, serial numbers with an "HR" prefix up to and including 10010, installed, certificated in any category.

NOTE 1: P/N 41105950 is the P/N assigned by HR Textron, which is the actuator manufacturer. Bell Helicopter Textron, Inc. (BHTI) has assigned P/N 205-076-036 to this part when fitted with a support mount. P/N 41000470 is the P/N assigned by HR Textron; BHTI has assigned P/N 212-076-005 to this part when fitted with a support mount.

NOTE 2: 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 (d) 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 an actuator piston from unthreading from its rod end, loss of control of the main rotor, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 25 hours time-in-service (TIS), inspect the tab on the NAS513-6 locking washer on each actuator for any twisting or damage in accordance with the Accomplishment Instructions, paragraph A., of HR Textron Alert Service Bulletin (ASB) No. 41000470-67A-05, Revision 1, dated October 19, 2000 or HR Textron ASB No. 41105950-67A-01, Basic Issue, dated October 19, 2000, as applicable to the affected actuator P/N. Replace any twisted or damaged locking washer with an airworthy NAS1193K6C locking device before further flight.

(b) Within 100 hours TIS or at the next actuator overhaul, whichever occurs first, replace the NAS513-6 locking washer on each actuator with an airworthy NAS1193K6C locking device.

(c) Installation of an airworthy NAS1193K6C locking device on each of the three actuators constitutes terminating action for the requirements of this AD.

(d) 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, 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 Certification Office.

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

(e) 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.

(f) The inspections and modifications shall be done in accordance with the Accomplishment Instructions, paragraph A., of HR Textron Alert Service Bulletin No. 41000470-67A-05, Revision 1 or HR Textron ASB No. 41105950-67A-01, Basic Issue, both dated October 19, 2000, as applicable to the affected actuator P/N. 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 HR Textron, 25200 W. Rye Canyon Road, Santa Clarita, California 91355-1265, telephone (611) 294-6000, fax (661) 259-9622. 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.

NOTE 4: BHTI ASB No.'s 205-00-79, 205B-00-33, 212-00-109, 412-00-105, and 412CF-00- 12, all dated October 19, 2000, pertain to the subject of this AD and include the applicable HR Textron Alert Service Bulletins.

(g) This amendment becomes effective on December 28, 2000.

This amendment adopts a new AD for BHTI Model 205A-1, 205B, 212, 412, and 412CF helicopters. This AD requires, within 25 hours time-in-service (TIS), inspecting the tab on the NAS513-6 locking washer on all actuators, part number (P/N) 41105950, serial number with an "HR" prefix up to and including 490 and P/N 41000470, serial numbers with a prefix of "HR" up to and including 10010, for a twisted or damaged tab. P/N's 41105950 and 41000470 were assigned by the manufacturer; the BHTI P/N's are 205-076-036 and 212-076-005. Replacing any twisted or damaged locking washer with an airworthy NAS1193K6C locking device is required before further flight. Replacing any NAS513-6 locking washer with an airworthy NAS1193K6C locking device, regardless of the condition of the tab, is required within 100 hours TIS or at the next actuator overhaul, whichever occurs first. Installing an airworthy NAS 1193K6C locking device on all actuators constitutes terminating action for the requirements of this AD. This AD is prompted by the discovery of a damaged locking washer. The damage to the locking washer was discovered when an operator experienced a problem with a collective control while attempting to take off. The collective control could not be moved upward from the full down position. Further inspection revealed that the lower piston of the actuator had unthreaded and separated from the lower rod end, causing the piston to make contact with the rod end support assembly and lodge itself against the rod end shank at an angle limiting any movement of the collective control. The collective servo cylinder assembly is used to provide irreversible collective control of the main rotor. Because the actuator end locking washer failed, the servo lower piston could rotate inside the lower servo head assembly and unthread itself from the rod end. This condition, if not corrected, could cause loss of control of the main rotor and subsequent loss of controlof the helicopter.

The FAA has reviewed HR Textron Alert Service Bulletin (ASB) No. 41000470-67A-05, Revision 1 and HR Textron ASB No. 41105950-67A-01, Basic Issue, both dated October 19, 2000, which describe procedures for inspecting and replacing certain locking washers. BHTI has issued ASB No.'s 205-00-79, 205B-00-33, 212-00-109, 412-00-105, and 412CF-00-12, all dated October 19, 2000, which include the applicable HR Textron Alert Service Bulletins.

Since an unsafe condition has been identified that is likely to exist or develop on other BHTI Model 205A-1, 205B, 212, 412, and 412CF helicopters of the same type designs, this AD is being issued to prevent an actuator piston from unthreading itself from its rod end causing loss of collective control and subsequent loss of control of the helicopter. This AD requires inspecting the locking washers on all actuators for twisting or damage to the tab and replacing any locking washer that has a twisted or damaged tab. Replacingcertain locking washers, regardless of condition, is also required within 100 hours TIS or at the next actuator overhaul, whichever occurs first. Installing an airworthy NAS1193K6C locking device on all actuators constitutes terminating action for the requirements of this AD. The actions must be accomplished in accordance with the HR Textron service bulletins described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability of the helicopter. Therefore, the actions described previously are required at the specified time intervals, 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.

The FAA estimates that 500 helicopters will be affected by this AD. It will take approximately 1 work hour to inspect the locking washer, 6 work hours per helicopter to replace the three locking devices on each helicopter, and the average labor rate is $60 per work hour. Required parts will cost approximately $20 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $190,000, assuming all the locking devices on all the helicopters are replaced.

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 onor 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 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-49-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, 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 adding a new airworthiness directive to read as follows: