AD 99-15-13

This amendment supersedes Airworthiness Directive (AD) 98-09-09, which currently requires replacing the internal cooling air fan with a fan that incorporates a white impeller on all Alexander Schleicher Segelflugzeugbau (Alexander Schleicher) Model ASH 26E sailplanes. This AD requires inspecting the internal cooling air fan for damage, and replacing any fan that does not incorporate a black impeller with a fan that incorporates a black impeller either immediately or at a certain time period, depending on the results of the inspection. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany. The actions specified by this AD are intended to prevent failure of the internal cooling system air fan caused by a certain design configuration of the impeller, which could cause the engine to overheat with possible engine failure.

Final rule

99-15-13 ALEXANDER SCHLEICHER SEGELFLUGZEUGBAU: Amendment 39-11234; Docket No. 99-CE-06-AD; Supersedes AD 98-09-09; Amendment 39-10489.

Applicability: Model ASH 26E sailplanes, all serial numbers, certificated in any category; that are equipped with an internal cooling system air fan that does not incorporate a black impeller, part number (P/N) R1K074.

NOTE 1: This AD applies to each sailplane 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 sailplanes 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 (e) 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 in the body of this AD, unless already accomplished.

To prevent failure of the internal cooling system air fan caused by a certain design configuration of the impeller, which could cause the engine to overheat with possible engine failure, accomplish the following:

(a) Within the next 30 calendar days after the effective date of this AD, inspect the internal cooling air fan for damage in accordance with Alexander Schleicher Technical Note No. 5, dated July 23, 1998.

(b) Replace the internal cooling system air fan with a fan that incorporates a black impeller, P/N R1K074, at whichever of the compliance times below (paragraphs (b)(1) and (b)(2) of this AD) that applies. Accomplish this replacement in accordance with Mid-West Service Bulletin No. 002, dated November 13, 1997:

(1) Prior to further flight if damage is found in the internal cooling air fan during the inspection required by paragraph (a) of this AD; or

(2) Within the next 9 calendar months after the effective date of this AD if damage is not found during the inspection required by paragraph (a) of this AD.

(c) As of the effective date of this AD, no person may install, on any affected sailplane, an internal cooling system air fan that does not incorporate a black impeller, P/N R1K074, as specified in Mid-West Service Bulletin No. 002, dated November 13, 1997; and Alexander Schleicher Technical Note No. 5 , dated July 23, 1998.

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

(e) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(f) Questions or technical information related to Alexander Schleicher Technical Note No. 5 , dated July 23, 1998, and Mid-West Service Bulletin No. 002, dated November 13, 1997, should be directed to Alexander Schleicher Segelflugzeugbau, 6416 Poppenhausen, Wasserkuppe, Federal Republic of Germany; telephone: 49.6658.890 or 49.6658.8920; facsimile: 49.6658.8923 or 49.6658.8940. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

(g) The inspection required by this AD shall be done in accordance with Alexander Schleicher Technical Note No. 5, dated July 23, 1998. The replacement required by this AD shall be done in accordance with Mid-West Service Bulletin No. 002, dated November 13, 1997. 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 Alexander Schleicher Segelflugzeugbau, 6416 Poppenhausen, Wasserkuppe, Federal Republic of Germany. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, 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 German AD 1998-391, dated October 8, 1998.

(h) This amendment supersedes AD 98-09-09, Amendment 39-10489.

(i) This amendment becomes effective on September 13, 1999.

Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Alexander Schleicher Model ASH 26E sailplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on April 26, 1999 (64 FR 20231). The NPRM proposed to supersede AD 98-09-09, Amendment 39-10489 (63 FR 20308, April 24, 1998). AD 98-09-09 currently requires replacing the internal cooling air fan with a fan that incorporates a white impeller, part number (P/N) R1K059. The NPRM proposed to require inspecting the internal cooling air fan for damage, and replacing any fan that does not incorporate a black impeller, P/N R1K074, with a fan that incorporates a P/N R1K074 impeller. The replacement would be accomplished either immediately or at a certain time period, depending on the results of the inspection.

Accomplishment of the proposed actions as specified in the NPRM would be required in accordance with Alexander Schleicher Technical Note No. 5 , dated July 23, 1998, and Mid-West Service Bulletin No. 002, dated November 13, 1997.

The NPRM was the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Germany.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Differences Between the Service Bulletin, the German AD, and This AD
Alexander Schleicher Technical Note No. 5, dated July 23, 1998, specifies inspecting the internal air cooling air fan prior to further flight, and German AD 1998-391, dated October 8, 1998, requires the inspection prior to further flight on sailplanes registered in Germany.

The FAA does not have justification to require the inspection prior to further flight. The FAA is utilizing the inspection compliance time of "within the next 30 calendar days after the effective date of the AD." The FAA is utilizing the replacement compliance time of "within the next 9 calendar months after the effective date of the AD", or if damage is found during the inspection, "prior to further flight."

Compliance Time of This AD
Although a damaged impeller blade is only unsafe while the affected sailplanes are in flight, the condition could occur at any time. For example, damage could occur on one sailplane with 25 hours time-in-service (TIS) while not occurring on another until 250 hours TIS. This is due to different usage levels and the various ways sailplanes are operated and utilized. In addition, the average monthly usage of the affected sailplane ranges throughout the fleet. For example, one owner may operate the sailplane 25 hours TIS in one week, while another owner may operate the sailplane 25 hours TIS in one year. In order to assure that the unsafe condition is detected and corrected on all affected sailplanes in a timely manner without inadvertently grounding any affected sailplane, the FAA is utilizing compliance based on calendar time instead of hours TIS.

Cost Impact
The FAA estimates that 9 sailplanes in the U.S. registry will be affected by this AD, that it will take approximately 14 workhours per sailplane to accomplish this AD, and that the average labor rate is approximately $60 an hour. Parts are available from the manufacturer at no cost. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $7,560, or $840 per sailplane.

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 copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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 removing Airworthiness Directive (AD) 98-09-09, Amendment 39-10489 (63 FR 20308, April 24, 1998), and by adding a new airworthiness directive (AD) to read as follows: