AD 2003-02-06

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 407 helicopters. This action requires visually inspecting certain tailboom gearbox support castings (castings) for cracks and replacing the tailboom assembly if a crack is found. This amendment is prompted by an incident in which a crack was discovered on the casting that holds the tail rotor gearbox and vertical fin. The actions specified in this AD are intended to detect a crack in the casting and prevent failure of the casting, loss of the vertical fin and tail rotor, and subsequent loss of control of the helicopter.

Final rule; request for comments.

2003-02-06 Bell Helicopter Textron Canada Limited: Amendment 39- 13023. Docket No. 2002-SW-33-AD.

Applicability: Model 407 helicopters, serial numbers (S/N) 53000 through 53475, with tailboom assemblies, part numbers (P/Ns) 407- 030-801-105 or -107, or 407-530-014-103, having S/N 53390 through 53440, 53449, BP921, BP1014, and tail rotor gearbox support casting (casting), part number (P/N) 406-030-121-105, having S/N 980867/01- 2, 980867/01-3, 980867/01-4, 980867/01-5, 980867/01-8, 980867/01-9, and 980867/01-10, 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 (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 detect a crack in the casting, failure of the tail rotor, loss of the tailboom, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 10 hours time-in-service (TIS) or 7 days, whichever occurs first, determine if an affected tailboom is installed, and if so, determine if an affected casting is installed, in accordance with Part I of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. 407-02-53, dated June 5, 2002 (ASB), except reporting to the manufacturer is not required.

(b) If an affected tailboom and casting are installed, before further flight and thereafter at intervals not to exceed 25 hours TIS until replacement tailboom, P/N 407-030-801-203, is installed, visually inspect the casting for a crack in accordance with Part II, steps 3-5 and 8, of the Accomplishment Instructions of the ASB, except that reporting to the manufacturer is not required.

(1) If a crack is found, before further flight, replace the tailboom assembly with an airworthy tailboom assembly having a serial number other than those serial-numbered tailboom assemblies listed in the Applicability section of this AD.

(2) If a crack is found, report the following information within 7 days to the FAA, Rotorcraft Directorate, ASW-111, Attention: Sharon Miles, 2601 Meacham Blvd., Fort Worth, TX 76137; or via Email to: sharon.y.miles@faa.gov; or via FAX at (817) 222-5961: Tailboom P/N, S/N, number of hours TIS, crack location, and crack size. Information collection requirements contained in this AD have been approved by the Officeof Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

(c) Replacing the tailboom with a tailboom assembly having a serial number other than those listed in the Applicability section of this AD is a 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, Regulations Group, 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, Regulations Group.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(e) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199to operate the helicopter to a location where the requirements of this AD can be accomplished.

(f) Determining if affected parts are installed and visually inspecting for a crack shall be done in accordance with Bell Helicopter Textron Alert Service Bulletin, No. 407-02-53, dated June 5, 2002, Part I and Part II, Accomplishment Instructions. 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 Canada, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450) 437- 2862 or (800) 363-8023, fax (450) 433-0272. 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.

(g) This amendment becomes effective on February 10, 2003.

Note 3: The subject of this AD isaddressed in Transport Canada (Canada) AD CF-2002-32R1, dated July 31, 2002.

Transport Canada, the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on Bell Model 407 helicopters. Transport Canada advises that there has been one occurrence of a cracked tail rotor gearbox support casting that is part of the tailboom assembly. They state that the crack originated from a weld repair made during fabrication of the part and that Bell has identified other castings that have the same repair and potential for cracking.

Bell has issued Bell Helicopter Textron Alert Service Bulletin, No. 407-02-53, dated June 5, 2002, which specifies a procedure for determining if an affected tailboom and casting are installed, and specifies an initial and 25-hour time-in-service recurring visual inspections of the casting for cracks. Transport Canada classified this alert service bulletin as mandatory and issued AD No. CF-2002-32R1, dated July 31, 2002, to ensure the continued airworthiness of these helicopters in Canada.

This helicopter model is manufactured in Canada and is type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, Transport Canada has kept the FAA informed of the situation described above. The FAA has examined the findings of Transport Canada, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

This unsafe condition is likely to exist or develop on other helicopters of the same type design registered in the United States. Therefore, this AD is being issued to detect a crack in the casting and prevent failure of the casting, loss of the vertical fin and tail rotor, and subsequent loss of control of the helicopter. This AD requires determining if an affected tailboom assembly and casting are installed, and if so, visually inspecting the casting for a crack before further flight at intervals not to exceed 25 hours time-in- service (TIS). Replacing any tailboom assembly that has a cracked casting is also required before further flight. The actions must be accomplished in accordance with the alert service bulletin described previously. Replacing the tailboom with a tailboom assembly having a serial number other than those listed in the Applicability section of this AD is a terminating action for the requirements of this AD. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability and structural integrity of the helicopter. Therefore, inspecting for a crack in affected castings is required within 10 hours TIS or 7 days, whichever occurs first, 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 284 helicopters will be affected by this AD and that it will take approximately 1.5 work hours to determine if an affected tailboom assembly and casting are installed and 25 work hours to replace a tailboom. There are seven helicopters that will require repetitively inspecting the affected casting; it will take approximately 1 work hour to conduct the visual inspection of the casting. The average labor rate is $60 per work hour. If a crack is found in the casting, required parts will cost approximately $64,578 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $573,786, assuming (1) a one-time inspection for 284 helicopters to determine if affected tailbooms and castings are installed; and (2) the tailboom is replaced on the seven helicopters after 204 repetitive inspections. The manufacturer states that they are offering a prorated warranty credit for replacement tailboom, P/N 407-030-801-203.

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 onthe 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. 2002-SW-33-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 implicationsunder 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: