AD 2004-14-15

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-400 airplanes. That AD currently requires revising the Normal and Abnormal sections of the airplane flight manual (AFM) to include procedures that enable the flightcrew to determine if the main landing gear (MLG) is extended before landing, and to take appropriate actions if necessary. This amendment adds an airplane to the applicability, and requires replacing the existing MLG downlock proximity sensors with new, improved sensors. After the replacement, this action also requires removing from the AFM the revision to the Normal and Abnormal sections required by the existing AD. The actions specified by this AD are intended to prevent failure of the MLG downlock proximity sensors on the same MLG at the same time, which could result in the MLG's failure to extend during landing, and cause injury to flightcrew and passengers. This action is intended to address the identified unsafe condition.

Final rule.

2004-14-15 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 39-13724. Docket 2002-NM-234-AD. Supersedes AD 2001-11-10, Amendment 39-12253.

Applicability: Model DHC-8-400 airplanes, serial numbers 4001 through 4055 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the main landing gear (MLG) downlock proximity sensors on the same MLG at the same time, which could result in the MLG's failure to extend during landing, and cause injury to flightcrew and passengers, accomplish the following:

Restatement of the Requirements of AD 2001-11-10

Airplane Flight Manual (AFM) Revision

(a) Within 14 days after June 21, 2001 (the effective date of AD 2001-11-10, amendment 39-12253), revise the Normal and Abnormal sections of the airplane flight manual (AFM) by inserting the following into Section 4.21, opposite page 4.21.1. This may be accomplished by inserting a copy of this AD in the AFM.

Caution

If illumination of LEFT gear safe (green), and LEFT gear unsafe (red), and landing gear handle (amber) advisory lights with the landing gear handle in the up position.

Or

Illumination of RIGHT gear safe (green), and RIGHT gear unsafe (red), and landing gear handle (amber) advisory lights with the landing gear handle in the up position.

1. Perform an Alternate Landing Gear extension, See paragraph 4.21.

Warning

Selection of the gear down without following the Alternate Landing Gear Extension procedure may result in the affected gear being trapped inside the nacelle.

2. Visually inspect Main Landing Gear to confirm that it has been extended.

Warning

A down and locked indication of the affected main landing gear is not a valid indication of the gear position.

3. Insert hydraulic pump handle in socket and operate for a minimum of 12 full strokes and ensure resistance to pump handle movement.

4. Observe the LEFT gear safe (green) and RIGHT gear safe (green) advisory lights are illuminated and the LEFT gear unsafe (red) and RIGHT gear unsafe (red) and the landing handle (amber) advisory lights are extinguished."

New Requirements of This AD

Replacement

(b) Within 6 months after the effective date of this AD, replace the left-hand and right-hand MLG downlock proximity sensors with new, improved sensors having new part numbers, per the Accomplishment Instructions of Bombardier Service Bulletin 84-32-09, Revision A, dated November 20, 2001. Once the sensors have been replaced, the AFM revision required by paragraph (a) of this AD must be removed from the AFM.

Note 1: Bombardier Service Bulletin 84-32-09 references Menasco Aerospace Service Bulletin 46400-32-09, dated May 15, 2001, as an additional source of service information for accomplishment of the replacement. The Menasco service bulletin is included in the Bombardier service bulletin.

Replacements Accomplished per Previous Issue of Service Bulletin

(c) Replacements accomplished before the effective date of this AD per Bombardier Service Bulletin 84-32-09, dated May 18, 2001, are considered acceptable for compliance with the corresponding action specified in this AD.

Alternative Methods of Compliance

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

Incorporation by Reference

(e) Unless otherwise specified in this AD, the actions shall be done in accordance with Bombardier Service Bulletin 84-32-09, Revision A, dated November 20, 2001. 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, TransportAirplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

Note 2:
The subject of this AD is addressed in Canadian airworthiness directive CF-2001-16R1, dated June 3, 2002.

Effective Date

(f) This amendment becomes effective on August 13, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 2001-11-10, amendment 39-12253 (66 FR 30305, June 6, 2001), which is applicable to certain Bombardier Model DHC-8-400 series airplanes, was published in the Federal Register on May 7, 2004 (69 FR 25503). The action proposed to require revising the Normal and Abnormal sections of the airplane flight manual (AFM) to include procedures that enable the flightcrew to determine if the main landing gear (MLG) is extended before landing, and to take appropriate actions if necessary. That action also proposed to require adding an airplane to the applicability, and replacing the existing MLG downlock proximity sensors with new, improved sensors. After the replacement, that action also proposed to require removing from the AFM the revision to the Normal and Abnormal sections required by the existing AD.

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

There are approximately 15 airplanes of U.S. registry that will be affected by this AD.

The revision of the AFM that is currently required by AD 2001-11-10 takes approximately 1 work hour per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the previously required actions on U.S. operators is estimated to be $975, or $65 per airplane.

The replacement that is required by this new AD will take approximately 4 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts will be provided free of charge. Based on these figures, the cost impact of the new requirements of this AD 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.

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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-12253 (66 FR 30305, June 6, 2001), and by adding a new airworthiness directive (AD), amendment 39-13724, to read as follows: