# AD 94-17-06: Airbrake Stops Inspection

- Type: Airworthiness directive
- Status: Current
- Products: Burkhart Grob Luft-Und G 103 C Twin III SL, G103 Twin Astir, G103 Twin II, G103A Twin II Acro, G103C Twin III Acro, GROB G 109, GROB G 109B, G102 ASTIR CS, G102 CLUB ASTIR III, G102 CLUB ASTIR IIIb and G102 Standard Astir III
- Effective: September 30, 1994
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Glider
- Amendment: 39-9002
- Docket: 93-CE-16-AD
- Registered aircraft: 156 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/412C6A188881D37386256A4D006DF5E4.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/94-17-06

## Summary

This amendment adopts a new airworthiness directive (AD) that applies to GROB Luft und Raumfahrt (Grob) Models G102, G103, G109, and G109B gliders. This action requires inspecting (one-time) the airbrake stops for cracks in the surrounding gelcoat and to ensure that the outer airbrake swivel levers are in contact with the stops during operation, and repairing any gelcoat cracks or any airbrake stops not in contact with the swivel levers. Excessive wear caused the airbrake fence to jam on the upper shell of the wing on one of the affected gliders, resulting in an accident. The actions specified by this AD are intended to prevent airbrake failure caused by jamming of the airbrake fence, which could result in loss of control of the glider.

## The airworthiness directive

94-17-06 GROB LUFT UND RAUMFAHRT: Amendment 39-9002; Docket No. 93-CE-16- AD.

Applicability: Models G102, G103, G109, and G109B gliders (all serial numbers), certificated in any category.

Compliance: Required within the next 60 calendar days after the effective date of this AD, unless already accomplished.

To prevent airbrake failure caused by jamming of the airbrake fence, which could result in loss of control of the glider, accomplish the following:

  (a) Inspect the airbrake stops for cracks in the surrounding gelcoat and to ensure that the outer airbrake swivel levers are in contact with stops during operation in accordance with the instructions in Grob Service Bulletin TM 306-31, TM 315-49, TM 320-6, and TM 817-36 (one document), dated September 14, 1992.

  (b) Prior to further flight, repair any gelcoat cracks or any airbrake stops not in contact with the swivel levers in accordance with the instructions in Grob Service Bulletin TM 306-31, TM 315-49, TM320-6, and TM 817-36 (one document), dated September 14, 1992.

  (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, Brussels Aircraft Certification Office (ACO), FAA, Europe, Africa, and Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Brussels ACO.

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

  (d) The inspection required by this AD shall be done in accordance with Grob Service Bulletin TM 306-31, TM 315-49, TM 320-6, and TM 817-36 (one document), dated September 14, 1992. 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 GROB Luft und Raumfahrt GmbH, D-8939 Mattsies, Federal Republic of Germany. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief 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.

  (e) This amendment becomes effective on September 30, 1994.

## Rule preamble

### Supplementary information

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to GROB Luft und Raumfahrt Models G102, G103, G109, and G109B gliders was published in the Federal Register on March 15, 1993 (58 FR 13710). The action proposed to require inspecting (one-time) the airbrake stops for cracks in the surrounding gelcoat and to ensure that the outer airbrake swivel levers are in contact with stops during operation, and repairing any gelcoat cracks or any airbrake stops not in contact with the swivel levers. The proposed actions would be accomplished in accordance with Grob Service Bulletin TM 306-31, TM 315-49, TM 320-6, and TM 817-36 (one document), dated September 14, 1992.

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.

After careful review of all available information, 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 nor add any additional burden upon the public than was already proposed.

The FAA estimates that 282 gliders in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per glider to accomplish the required action, and that the average labor rate is approximately $55 an hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $15,510. This figure is based on the assumption that no affected glider owner/operator has accomplished the required action.

The FAA has determined that calendar time is the most desirable method of compliance for this AD because yearly operational times vary greatly throughout the fleet. For example, one glider operator might utilize the glider 10 hours time-in-service (TIS) in one month, while another may not utilize the glider 10 hours TIS in one year. Therefore, to maintain continuity and avoid inadvertent grounding of the affected gliders, compliance based upon calendar time is utilized.

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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

Section 39.13 - [AMENDED] 2. Section 39.13 is amended by adding a new AD to read as follows:

## Affected data sheets (4) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS G33EU](https://openairdocs.org/tcds/G33EU): Fiberglas-Technik Rudolf Lindner GmbH & Co. KG; names 4 of 4 models: G102 Standard Astir III, G102 CLUB ASTIR III, G102 CLUB ASTIR IIIb, G102 ASTIR CS
- [TCDS G39EU](https://openairdocs.org/tcds/G39EU): Fiberglas-Technik Rudolf Lindner GmbH & Co. KG; names 4 of 4 models: G103 Twin Astir, G103C Twin III Acro, G103A Twin II Acro, G103 Twin II
- [TCDS G43EU](https://openairdocs.org/tcds/G43EU): GROB Aircraft AG; names 2 of 2 models: GROB G 109B, GROB G 109
- [TCDS G57EU](https://openairdocs.org/tcds/G57EU): Fiberglas-Technik Rudolf Lindner GmbH & Co. KG; names 1 of 1 models: G 103 C Twin III SL

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 156 (156 by airframe model, 0 by engine model)
- Makers: Burkhart Grob Flugzeugbau 84, Burkhart Grob 71, Burkhart Grob Luft-Und Raumfah 1

Models with the most aircraft:

- [Burkhart Grob Flugzeugbau G102 ASTIR CS](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g102-astir-cs): 38 aircraft (airframe model)
- [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir): 35 aircraft (airframe model)
- [Burkhart Grob G 103 TWIN II](https://openairdocs.org/model/burkhart-grob-g-103-twin-ii): 30 aircraft (airframe model)
- [Burkhart Grob G-103A TWIN II ACRO](https://openairdocs.org/model/burkhart-grob-g-103a-twin-ii-acro): 26 aircraft (airframe model)
- [Burkhart Grob Flugzeugbau G102 CLUB ASTIR IIIB](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g102-club-astir-iiib): 10 aircraft (airframe model)
- [Burkhart Grob G103C TWIN III ACRO](https://openairdocs.org/model/burkhart-grob-g103c-twin-iii-acro): 7 aircraft (airframe model)
- [Burkhart Grob G103C TWIN III SL](https://openairdocs.org/model/burkhart-grob-g103c-twin-iii-sl): 4 aircraft (airframe model)
- [Burkhart Grob G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-g103-twin-astir): 4 aircraft (airframe model)
- [Burkhart Grob Flugzeugbau G102 CLUB ASTIR III](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g102-club-astir-iii): 1 aircraft (airframe model)
- [Burkhart Grob Luft-Und Raumfah G103C TWIN III ACRO](https://openairdocs.org/model/burkhart-grob-luft-und-raumfah-g103c-twin-iii-acro): 1 aircraft (airframe model)

All 10 models: https://openairdocs.org/ad/94-17-06/models.md
Every aircraft: https://openairdocs.org/ad/94-17-06/aircraft.md

Its text cites no advisory circulars or STCs.

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