AD 2004-02-05

This amendment adopts a new airworthiness directive (AD); applicable to certain Bombardier Model DHC-8-400, -401, and -402 airplanes; that requires replacing certain flight guidance modules with improved modules, and certain flight control electronic control units with improved units. This action is necessary to prevent loss of the autopilot or manual pitch trim, which may increase the workload of the flightcrew and, under certain conditions, could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

Final rule.

2004-02-05 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 39-13440. Docket 2002-NM-311-AD.

Applicability: Model DHC-8-400, -401, and -402 airplanes; certificated in any category; having serial numbers (S/Ns) 4001 through 4065 inclusive.

Compliance: Required as indicated, unless accomplished previously.

To prevent loss of the autopilot or manual pitch trim, which may increase the workload of the flightcrew and, under certain conditions, could result in reduced controllability of the airplane, accomplish the following:

Replacement of Flight Guidance Modules

(a) For airplanes with S/Ns 4001 through 4003 inclusive and 4005 through 4058 inclusive: Within 60 days after the effective date of this AD, replace flight guidance modules (FGMs) FGM1 and FGM2, part number (P/N) C12429AA06, with improved FGMs, P/N C12429AA07, and perform a Return-to-Service procedure, per Bombardier Service Bulletin 84-22-04, Revision 'B,' dated April 17, 2002.

Note 1: Bombardier Service Bulletin 84-22-04, Revision 'B,' refers to Thales Service Bulletin C12429A-22-003, dated November 29, 2001, as an additional source of service information for modifying FGMs from P/N C12429AA06 to P/N C12429AA07. The Thales service bulletin is included in the Bombardier service bulletin.

Replacement of Flight Control Electronic Control Units

(b) For all airplanes: Within 8 months after the effective date of this AD, replace flight control electronic control units (FCECUs), P/N 398500-1001 or -1003, with improved FCECUs, P/N 398500-1005, and perform a Return-to-Service procedure, per Bombardier Service Bulletin 84-27-14, Revision 'A,' dated April 2, 2002.

Note 2: Bombardier Service Bulletin 84-27-14, Revision 'A,' refers to Parker Service Bulletin 398500-27-235, dated January 9, 2002, as an additional source of service information for modifying FCECUs from P/N 398500-1001 or -1003 to P/N 398500-1005. The Parker service bulletin is included in the Bombardier service bulletin.

Alternative Methods of Compliance

(c) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(d) The actions shall be done in accordance with Bombardier Service Bulletin 84-22-04, Revision 'B,' dated April 17, 2002; and Bombardier Service Bulletin 84-27-14, Revision 'A,' dated April 2, 2002; as applicable. 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 Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Westbury, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 3: The subject of this AD is addressed in Canadian airworthiness directive CF-2002-25, dated April 25, 2002.

Effective Date

(e) This amendment becomes effective on March 5, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8- 400, -401, and -402 airplanes, was published in the Federal Register on November 18, 2003 (68 FR 65003). That action proposed to require replacing certain flight guidance modules (FGMs) with improved modules, and certain flight control electronic control units (FCECUs) with improved units.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

We estimate that 12 airplanes of U.S. registry will be affected by the required replacement of FGMs, that it will take approximately 1 work hour per airplane to accomplish this replacement, and that the average labor rate is $65 per work hour. Required parts will be provided at no charge. Based on these figures, the cost impact of this requirement on U.S. operators is estimated to be $780, or $65 per airplane.

We estimate that 15 airplanes of U.S. registry will be affected by the required replacement of the FCECUs, that it will take approximately 4 work hours per airplane to accomplish this required replacement, and that the average labor rate is $65 per work hour. Required parts will be provided at no charge. Based on these figures, the cost impact of this requirement on U.S. operators is estimated to be $3,900, or $260 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. The manufacturer may cover the cost of replacement parts associated with this AD, subject to warranty conditions. As a result, the costs attributable to the AD may be less than stated above.

Regulatory Impact

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.

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 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: