AD 96-06-04

This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, A Division of Textron Canada, Ltd., (BHTC) Model 206A and 206B helicopters, that currently requires an inspection of the main transmission input driveshaft assembly (driveshaft) at intervals of 300 hours time-in-service (TIS); the application of a zinc chromate primer inspection visual aid; and, daily visual checks of the driveshaft. This amendment requires inspections of the driveshaft at intervals of 300 hours TIS; the application of a self-adhesive temperature indicator visual inspection aid ; and, preflight visual owner/operator (pilot) checks of the driveshaft. This amendment is prompted by recent studies that indicate self-adhesive temperature indicators are a more reliable means of detecting overheat conditions on grease-lubricated couplings than the zinc chromate primers currently in use. The actions specified by this AD are intended to prevent failure of the driveshaft due to coupling wear or overheating, which could result in loss of power to the main rotor and a subsequent forced emergency landing.

Final rule

96-06-04 BELL HELICOPTER TEXTRON, A DIVISION OF TEXTRON CANADA, LTD.: Amendment 39-9541, Docket No. 94-SW-16-AD. Supersedes AD 81-04-08, Amendment 39-4037.

Applicability: Model 206A and 206B 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 conditionaddressed 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 as indicated, unless accomplished previously.

To prevent failure of the main transmission input driveshaft assembly (driveshaft) due to coupling wear or overheating, which could result in loss of power to the main rotor and a subsequent forced emergency landing, accomplish the following:

(a) Before the first flight of each day after the effective date of this AD, visually check the driveshaft, part number (P/N) 206-040-100-13, for: (1) grease leakage from the driveshaft couplings, P/N 206-040-108-005; and (2) visual damage and security of the clamps and bolts used to attach the driveshaft to the transmission and engine couplings. After compliance with paragraph (d) of this AD, also check the self-adhesive over-temperature indicators (over-temperature indicators) for overheating, deterioration, debonding, or discoloration. The visual checks may be performed by an owner/operator (pilot) holding at least a private pilot certificate, and must be entered into the aircraft records showing compliance with the visual check of this AD in accordance with sections 43.11 and 91.417(a)(2)(v) of the Federal Aviation Regulations.

(b) If any discrepancies are discovered as a result of the visual check performed in paragraph (a), accomplish the following before further flight:

(1) If there is any grease leakage or any indications of overheating, disassemble and inspect the driveshaft in accordance with the applicable maintenance manual and replace the over-temperature indicators in accordance with Part III of the Accomplishment Instructions of Alert Service Bulletin (ASB) No. 206-93-76, Revision B, dated September 6, 1994.

(2) If any "dot" on an over-temperature indicator has changed color to black, accomplish the corrective action in accordance with TABLE I and the accompanying Notes in ASB No. 206-93-76, Revision B, dated September 6, 1994.

(3) If there are any deteriorated, debonded, or discolored over-temperature indicator(s) that would prevent interpretation of the indicating "dots", replace those over- temperature indicator(s) in accordance with Part III of the Accomplishment Instructions of ASB No. 206-93-76, Revision B, dated September 6, 1994. If only one over-temperature indicator is missing, and no "dot" on any other over-temperature indicator on the same coupling is discolored or shows mechanical damage or degradation of the epoxy overcoating, the helicopter may be returned to service.

(4) If there are any loose or damaged clamps or bolts, secure the loose clamps or bolts and replace the damaged clamps or bolts in accordance with the applicable maintenance manual.

(c) Inspect and lubricate the driveshaft assembly, P/N 206-040-100-13, and driveshaft couplings, P/N 206-040-108-005, in accordance with the helicopter's maintenancemanual and according to the compliance schedule that follows, and thereafter, inspect and lubricate at intervals not to exceed 300 hours time-in-service (TIS):

(1) For helicopters with 250 hours TIS or more, compliance is required within the next 50 hours TIS; or,

(2) For helicopters with less than 250 hours TIS, compliance is required prior to attaining 300 hours TIS.

(d) Install the over-temperature indicators at the next 300 hours TIS driveshaft coupling inspection and lubrication in accordance with Part I of the Accomplishment Instructions of ASB No. 206-93-76, Revision B, dated September 6, 1994.

(e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(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) The inspections, maintenance and installation of over-temperature indicators shall be done in accordance with Alert Service Bulletin No. 206-93-76, Revision B, dated September 6, 1994. 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, A Division of Textron Canada, Ltd., 12,800 Rue L'Avenir, Mirabel, Quebec, Canada J7J1R4, ATTN: Product Support Engineering Light Helicopters. Copiesmay be inspected at the FAA, Office of the Assistant Chief Counsel, 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.

(h) This amendment becomes effective on April 25, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 81-04-08, Amendment 39-4037 (46 FR 12469, February 17, 1981), which is applicable to BHTC Model 206A and 206B helicopters, was published in the Federal Register on September 8, 1995 (60 FR 46790). That action proposed to require inspections of the driveshaft at intervals of 300 hours TIS; the application of a self-adhesive visual over-temperature indicator; and, preflight visual checks of the driveshaft. The checks described in the proposal (before the first flight of each day) may be performed by an owner/operator (pilot), but must be entered into the aircraft records showing compliance with the preflight check requirements of this AD in accordance with sections 43.11 and 91.417(a)(2)(v) of the Federal Aviation Regulations. The notice proposed to allow a pilot to perform these checks because they involve only a visual check for grease leakage, overheating, and security of the clamps and bolts used to attach the driveshaft to transmission and engine couplings. These checks can be performed equally well by a pilot or a mechanic. They involve checking items similar to those items that a pilot checks during a preflight check. The notice proposed that a mechanic inspect the driveshaft and driveshaft couplings at intervals of 300 hours TIS.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposal or the FAA's determination of the cost to the public. However, the FAA has reorganized paragraphs (a) and (b) to separate the requirements of the visual checks that may be performed by the pilot from the required corrective actions that must be performed by a mechanic if certain conditions are discovered during the visual check. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed with the exception oforganizational changes noted and various editorial changes. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 4,312 helicopters of U.S. registry will be affected by this AD, that it will take approximately one and one-half work hours per helicopter to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be provided by the manufacturer at no charge, but installation materials will cost approximately $10 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $431,200.

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.

For the reasons discussed above, I certify that this action (1) is not a " significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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 USC App. 106(g), 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by removing Amendment 39-4037 (46 FR 12469, February 17, 1981), and by adding a new airworthiness directive (AD), Amendment 39-9541, to read as follows: