AD 98-12-03

This amendment adopts a new airworthiness directive (AD) that applies to certain Alexander Schleicher Segelflugzeugbau (Alexander Schleicher) Models ASW-19 and ASK 21 sailplanes. This AD requires: modifying the rudder surface panels; replacing the airbrake bellcrank; and modifying the rear canopy hinge structure. 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 loss of the canopy caused by design deficiency, airbrake failure caused by cracking, and rudder panel flutter caused by high density altitude conditions, all of which could result in reduced sailplane controllability.

Final rule

98-12-03 ALEXANDER SCHLEICHER SEGELFLUGZEUGBAU: Amendment 39-10560; Docket No. 97-CE-102-AD.

Applicability: Model ASW-19 sailplanes (serial numbers 19019 through 19037, 19040, and 19042 through 19044), and Model ASK 21 sailplanes (serial numbers 21001 through 21345), certificated in any category.

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 (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 in the body of this AD, unless already accomplished.

To prevent loss of the canopy caused by design deficiency, airbrake failure caused by cracking, and rudder panel flutter caused by high density altitude conditions, all of which could result in reduced sailplane controllability, accomplish the following:

(a) Within the next 3 calendar months after the effective date of this AD, accomplish the following:

(1) For Alexander Schleicher Model ASW-19 sailplanes, modify the rudder panel in accordance with the Instructions section in Alexander Schleicher ASW 19 Technical Note No. 2, dated September 6, 1976.

(2) For Alexander Schleicher Model ASK 21 sailplanes, replace the airbrake bellcrank with an airbrake bellcrank of improved design in accordance with the Action section, paragraphs 3.1, 3.2, and 3.3 in Alexander Schleicher ASW 21 Technical Note No. 20, dated October 16, 1987.

(3) For Alexander Schleicher Model ASK 21 sailplanes, modify the rear canopy hinge in accordance with the Action section, paragraph 4.2, in Alexander Schleicher ASW 21 Technical Note No. 20, dated October 16, 1987.

(b) 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.

(c) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, Aircraft Certification Service, 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.

(d) Questions or technical information related to the service information referenced in this AD, should be directed to Alexander Schleicher Segelflugzeugbau, 6416 Poppenhausen, Wasserkuppe, Federal Republic of Germany. 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.

(e) The modifications and replacement required by this AD shall be done in accordance with Alexander Schleicher ASW 19 Technical Note 2, dated September 6, 1976, and Alexander Schleicher ASK 21 Technical Note 20, dated October 16, 1987. 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 No. 76-258, dated September 3, 1976, for the rudder panel condition; and German AD No.88-2, dated January 1, 1988, for the airbrake bellcrank and the rear canopy hinge conditions.

(f) This amendment becomes effective on July 14, 1998.

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 certain Alexander Schleicher Model ASW-19 and ASK 21 sailplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 17, 1998 (63 FR 13013). The NPRM proposed to require modifying the sailplanes rudder panel by stiffening the rudder panel, reinforcing the rear canopy hinge, and replacing the airbrake bellcrank. Accomplishment of the proposed actions as specified in the NPRM would be in accordance with Alexander Schleicher ASW 19 Technical Note 2, dated September 6, 1976, and Alexander Schleicher ASK 21 Technical Note 20, dated October 16, 1987.

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.

Compliance Time of This AD
The compliance time of this AD is presented in calendar time instead of hours time-in-service (TIS) because of the typical usage of the affected gliders. For example, an operator of an affected glider may only utilize the glider 50 hours TIS in a year, while another operator may utilize an affected glider 50 hours TIS in one month. The FAA has determined that a compliance based on calendar time should be utilized in this AD in order to assure that the unsafe condition is addressed on all gliders in a reasonable time period.

Cost Impact
The FAA estimates that 5 sailplanes in the U.S. registry will be affected by the rudder panel portion of this AD, that it will take approximately 10 workhours per sailplane to accomplish the rudder panel portion of this AD, and that the average labor rate is approximately $60 an hour. Parts cost approximately $50 per sailplane. Based on these figures, the total cost impact of the rudder panel portion of this AD on U.S. operators is estimated to be $3,250, or $650 per sailplane.

The FAA estimates that 30 sailplanes in the U.S. registry will be affected by the airbrake bellcrank portion of this AD, that it will take approximately 6 workhours per sailplane to accomplish the rudder panel portion of this AD, and that the average labor rate is approximately $60 an hour. Parts cost approximately $200 per sailplane. Based on these figures, the total cost impact of the airbrake bellcrank portion of this AD on U.S. operators is estimated to be $16,800, or $560 per sailplane.

The FAA estimates that 30 sailplanes in the U.S. registry will be affected by the rear canopy hinge portion of this AD, that it will take approximately 11 workhours per sailplane to accomplish the rear canopy hinge portion of this AD, and that the average labor rate is approximately $60 an hour. Parts cost approximately $15 per sailplane. Based on these figures, the total cost impact of the rear canopy hinge portion proposed AD on U.S. operators is estimated to be $20,250, or $675 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 adding a new airworthiness directive (AD) to read as follows: