AD 99-17-14

This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model DHC-8 series airplanes, that requires a one-time inspection of the spring assemblies located in the rudder control feel unit to verify that dual rate configuration springs are installed; and revising the Airplane Flight Manual to prohibit airplane operation from runways less than 75 feet wide, if necessary. This amendment also requires eventual replacement of any single rate configuration springs with dual rate configuration springs, which terminates the requirement for the AFM revision. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent an asymmetric rudder force condition, which could result in reduced controllability of the airplane and consequent potential for center line deviation.

Final Rule

99-17-14 BOMBARDIER, INC. (Formerly deHavilland, Inc.): Amendment 39-11262. Docket 99-NM-55-AD.

Applicability: Model DHC-8 series airplanes, as listed in Bombardier Alert Service Bulletin S.B. A8-27-82, dated July 10, 1998; certificated in any category.

NOTE 1: This AD applies to each airplane 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 airplanes 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 asymmetric rudder force condition, which could result in reduced controllability of the airplane and consequent potential for center line deviation, accomplish the following:

General Visual Inspection

(a) Within 100 flight hours or 14 days after the effective date of this AD, whichever occurs later: Perform a one-time visual inspection of the spring assemblies located in the rudder control feel unit to verify that dual rate configuration springs are installed, in accordance with Bombardier Alert Service Bulletin S.B. A8-27-82, dated July 10, 1998.

(1) If dual rate configuration springs are installed, no further action is required by this AD.

NOTE 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked."

AFM Revision

(2) If any single rate configuration springs are installed, prior to further flight: Revise the Limitations Section of the de Havilland Dash 8 Airplane Flight Manual (AFM) to include the following statement. This action may be accomplished by inserting a copy of this AD into the AFM.

"OPERATION FROM RUNWAYS LESS THAN 75 FEET WIDE IS PROHIBITED."

Terminating Action

(b) At the next scheduled maintenance visit, but no later than 36 months after the effective date of this AD: Replace any single rate configuration springs located in the rudder control feel unit with dual rate configuration springs, in accordance with Part C through Part H inclusive, of the Accomplishment Instructions of Bombardier Alert Service Bulletin S.B. A8-27- 82, dated July 10, 1998. Such replacement constitutes terminating action for the requirements of this AD. After the replacement has been accomplished, the AFM limitation required by paragraph (a)(2) of this AD may be removed from the AFM.

Spares Paragraph

(c) As of the effective date of this AD, no person shall install any spring assembly having part number 82760050-003 on any airplane.

Alternative Methods of Compliance

(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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

Special Flight Permits

(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 airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(f) Except as provided by paragraph (a)(2), the actions shall be done in accordance with Bombardier Alert Service Bulletin S.B. A8-27-82, dated July 10, 1998. 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, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in Canadian airworthiness directives CF- 98-39, dated October 23, 1998, and CF-98-39R1, dated December 31, 1998.

(g) This amendment becomes effective on September 24, 1999.

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 series airplanes was published in the Federal Register on June 22, 1999 (64 FR 33232). That action proposed to require a one-time inspection of the spring assemblies located in the rudder control feel unit to verify that dual rate configuration springs are installed; and revising the Airplane Flight Manual to prohibit airplane operation from runways less than 75 feet wide, if necessary. That proposal also would require eventual replacement of any single rate configuration springs with dual rate configuration springs, which would terminate the requirement for the AFM revision.

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 thecost to the public.

Explanation of Change Made to Proposal

The FAA has added a note to the final rule to clarify the definition of a general visual inspection.

Conclusion

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

Cost Impact

The FAA estimates that 235 airplanes of U.S. registry will be affected by this AD.

It will take approximately 1 work hour per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $14,100, or $60 per airplane.

It will take approximately 10 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be $141,000, or $600 per airplane.

If accomplished, it will take approximately 1 work hour per airplane to accomplish the AFM revision, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AFM revision on U.S. operators, if accomplished, is estimated to be $14,100, or $60 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

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

39.13 [Amended]

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