AD 96-23-17

This amendment adopts a new airworthiness directive (AD), applicable to certain de Havilland Model DHC-8-102 and -103 series airplanes, that requires repetitive external inspections to detect cracks in the skin exterior of the fuselage at floor level, and repair, if necessary. This amendment also requires repetitive internal inspections to detect cracks of the subject area, which terminates the repetitive external inspections. This amendment is prompted by a report that one of the tasks in the Maintenance Program Airworthiness Limitations List inadvertently excluded certain airplanes from the instructions for the inspections. The actions specified by this AD are intended to prevent undetected cracking of the frames and skin panels of the fuselage, which could result in reduced structural integrity of the airplane.

Final rule

96-23-17 DE HAVILLAND, INC.: Amendment 39-9822. Docket 95-NM-163-AD.
Applicability: Model DHC-8-102 and-103 series airplanes having serial numbers 101 through 180, inclusive; on which de Havilland Modification 8/0427 has been installed, and on which Maintenance Program Manual PSM 1-8-7, Task 5310/30C (Section 3-53, page 12, dated August 10, 1993) has not been accomplished; certificated in any category.

NOTE 1: This AD applies to each airplane 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 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 (c) 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 undetected cracking of the frames and skin panels of the fuselage, which could result in reduced structural integrity of the airplane, accomplish the following:

(a) Prior to the accumulation of 15,343 total flight cycles, or within 200 landings after the effective date of this AD, whichever occurs later, perform an external detailed visual inspection to detect cracks in the left-and right-hand skin exterior of the fuselage at floor level, in accordance with paragraph III, External Inspection, of the Accomplishment Instructions of de Havilland Service Bulletin S.B. 8-53-48, dated August 26, 1994.

(1) If no crack is detected, repeat the external detailed visual inspection thereafter at intervals not to exceed 750 landings.(2) If any crack is detected, prior to further flight, perform an internal visual inspection to detect cracks of the fuselage frames in accordance with the service bulletin. Accomplishment of this internal visual inspection constitutes terminating action for the repetitive external detailed visual inspections required by of paragraph (a)(1) of this AD.

(i) If no crack is detected during the internal inspection, prior to further flight, repair the cracked area(s) found during the external inspection, in accordance with the de Havilland DHC-8 Structural Repair Manual; or in accordance with a method approved by Transport Canada; or in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Repeat the internal inspection thereafter at intervals specified in accordance with the Dash 8 Maintenance Program Manual.

(ii) If any crack is detected during the internal inspection, prior to further flight,repair all cracks found during both the external and internal inspections, in accordance with the de Havilland DHC-8 Structural Repair Manual, or in accordance with a method approved by Transport Canada Aviation; or in accordance with a method approved by the Manager, New York ACO, FAA, Engine and Propeller Directorate. Repeat the internal inspection thereafter at intervals specified in accordance with the Dash 8 Maintenance Program Manual.

(b) Prior to the accumulation of 31,000 flight cycles, or within 12 months after the effective date of this AD, whichever occurs later, perform an internal visual inspection to detect cracking of the fuselage frames, in accordance with de Havilland Service Bulletin S.B. 8-53-48, dated August 26, 1994. Accomplishment of the internal visual inspection constitutes terminating action for the repetitive external detailed visual inspections required by paragraph (a)(1) of this AD.

(1) If no cracking is detected during the internal inspection, repeat the internal inspection thereafter at intervals specified in accordance with the Dash 8 Maintenance Program Manual.

(2) If any cracking is detected during the internal inspection, prior to further flight, repair it in accordance with the de Havilland DHC-8 Structural Repair Manual, or in accordance with a method approved by Transport Canada Aviation; or in accordance with a method approved by the Manager, New York ACO, FAA, Engine and Propeller Directorate. Repeat the internal inspection thereafter at intervals specified in accordance with the Dash 8 Maintenance Program Manual.

(c) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

(d) 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.

(e) The inspections shall be done in accordance with de Havilland Service Bulletin S.B. 8-53-48, dated August 26, 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 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, New York Aircraft Certification Office, Engine and Propeller Directorate, 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.

(f) This amendment becomes effective on December 26, 1996.

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 de Havilland Model DHC-8-102 and -103 series airplanes was published in the Federal Register on August 30, 1996 (61 FR 45914). That action proposed to require repetitive external detailed visual inspections to detect cracks in the left-and right-hand skin exterior of the fuselage at the floor level. That action also proposed to require repetitive internal visual inspections to detect cracks of the fuselage frames; initiation of these inspections would constitute terminating action for the repetitive external inspection requirements.

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
The FAA estimates that 80 de Havilland Model DHC-8-102 and -103 series airplanes of U.S. registry will be affected by this AD.

The required external inspections will take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $4,800, or $60 per airplane, per inspection.

The required internal inspections will take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $14,400, or $180 per airplane, per inspection.

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.

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: