AD 98-13-04

This amendment adopts a new airworthiness directive (AD) that applies to all Glaser-Dirks Flugzeugbau GmbH (Glaser-Dirks) Models DG-100 and DG-400 gliders. This AD requires repetitively inspecting the airbrakes to assure they retract at their outboard end first, and repairing the airbrakes if they do not retract at their outboard end first; and repetitively inspecting the airbrake torque tube in the fuselage for cracks or deformations, and reinforcing or replacing, as necessary, if cracks or deformations are found in the airbrake torque tube. 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 overloading of the airbrake control system caused by free play between the bellcrank and airbrake plate, which could result in failure of the operating lever of the airbrake torque tube in the fuselage.

Final rule

98-13-04 GLASER-DIRKS FLUGZEUGBAU GMBH: Amendment 39-10592; Docket No. 97-CE-133-AD. Applicability: Models DG-100 and DG-400 gliders, all serial numbers, certificated in any category.

NOTE 1: This AD applies to each glider 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 gliders 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 in the body of this AD, unless already accomplished.

To prevent overloading of the airbrake control system caused by free play between the bellcrank and airbrake plate, which could result in failure of the operating lever of the airbrake torque tube in the fuselage, accomplish the following:

(a) Within the next 3 calendar months after the effective date of this AD, and thereafter at intervals not to exceed 12 calendar months, inspect the airbrakes to assure they retract at their outboard end first in accordance with DG-Flugzeugbau GmbH Working instructions No. 1 for Technical Notes No. 301/18, 323/9, and 826/34, dated November 4, 1996. If the airbrakes do not retract at their outboard end first, prior to further flight, repair the airbrakes in accordance with the above-referenced working instructions.

(b) Within the next 30 calendar days after the effective date of this AD, and thereafter at intervals not to exceed 12 calendar months, inspect the airbrake torque tube in the fuselage for cracks or deformations in accordance with DG-Flugzeugbau GmbH Working instructions No. 2 for Technical Notes No. 301/18, 323/9, and 826/34, dated November 4, 1996. If cracks or deformations are found in the airbrake torque tube, prior to further flight, reinforce or replace, as necessary, in accordance with the above-referenced working instructions.

(c) 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 glider to a location where the requirements of this AD can be accomplished.

(d) An alternative method of compliance or adjustment of the initial or repetitive 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.

(e) Questions or technical information related to service information referenced in this AD should be directed to DG-Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, Germany; telephone: +49 7257-89-0; facsimile: +49 7257-8922. 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.

(f) The inspections, repair, reinforcement, and replacement required by this AD shall be done in accordance with DG-Flugzeugbau Working Instruction No. 1 and No. 2 for Technical Notes No. 301/18, No. 323/9, and No. 826/34, dated November 4, 1996. 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 DG-Flugzeugbau GmbH, Postfach 4120, D-76625 Bruchsal 4, 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 97-011, dated January 30, 1997.

(g) This amendment becomes effective on August 2, 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 all Glaser-Dirks Models DG-100 and DG-400 gliders airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on April 1, 1998 (63 FR 15793). The NPRM proposed to require repetitively inspecting the airbrakes to assure they retract at their outboard end first, and repairing the airbrakes if they do not retract at their outboard end first; and repetitively inspecting the airbrake torque tube in the fuselage for cracks or deformations, and reinforcing or replacing, as necessary, if cracks or deformations are found in the airbrake torque tube. Accomplishment of the proposed action as specified in the NPRM would be in accordance with DG-Flugzeugbau Technical Note No. 301/18, No. 323/9, and No. 826/34, dated November 4, 1996.

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
Although the problems identified with the airbrake control system will only be unsafe during flight, this condition is not a result of the number of times the glider is operated. The chance of this situation occurring isthe same for a glider with 10 hours time-in-service (TIS) as it is for a glider with 500 hours TIS. For this reason, 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 45 gliders in the U.S. registry will be affected by this AD, that it will take approximately 4 work hours per glider to accomplish these inspections, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $10,800, or $240 per glider.

These figures are based only on the initial inspections and do not take into account the costs of any repetitive inspections or reinforcements and modifications that will be needed based on the results of these inspections. The FAA has no way of determining the number of repetitive inspections each owner/operator of the affected airplanes will incur, or the number of airbrake control systems that will require modification, reinforcement, or repair.

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: