AD 98-23-10

This amendment adopts a new airworthiness directive (AD) that applies to all Burkhart GROB Luft-und Raumfahrt GmbH (Grob) Model G 109B gliders. This AD requires inspecting the engine mounting frame for paint scratches and damage (abrasions, notches, or chafing); and repairing any paint scratches, and repairing or replacing any engine mounting frame that is found damaged. 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 detect and correct damage to the engine mounting frame, which could result in failure of the engine mount structure with consequent loss of the engine.

Final rule

98-23-10 BURKHART GROB LUFT-UND RAUMFAHRT GMBH: Amendment 39-10876; Docket No. 98-CE-72-AD.

Applicability: Model G 109B 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 (g) 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 alreadyaccomplished.

To detect and correct damage to the engine mounting frame, which could result in failure of the engine mount structure with consequent loss of the engine, accomplish the following:

(a) Within the next 3 calendar months after the effective date of this AD, inspect the engine mounting frame for paint scratches and damage (abrasions, notches, or chafing) in accordance with the Action section of Grob Service Bulletin TM 817-45, dated July 27, 1995.

(b) If a paint scratch(es), but no damage, is found during the inspection required by paragraph (a) of this AD, prior to further flight, remove all flakes and dust from the area, degrease the tube and apply a protective anti-corrosion coat, and shorten the warm air duct or replace it if damaged. Accomplish the warm air duct modification or replacement in accordance with the maintenance manual.

(c) If a paint scratch(es) and damage are both found during the inspection required by paragraph (a) of this AD, accomplish the following:

(1) Prior to further flight, remove all flakes and dust from the area; and

(2) Perform the actions specified in paragraph (d) or (e) of this AD, as applicable. Accomplish these actions at the compliance times specified in the applicable paragraphs.

(d) If damage (abrasions, notches, or chafing) is found during the inspection required by paragraph (a) of this AD, and the damage is 0.7 millimeters (mm) or less in depth as specified in paragraph 3(b) of the Action section of Grob Service Bulletin TM 817-45, dated July 27, 1995, prior to further flight, degrease the tube and apply a protective anti-corrosion coat, and shorten the warm air duct or replace it if damaged. Accomplish the warm air duct modification or replacement in accordance with the maintenance manual. Within 6 calendar months after the inspection required by paragraph (a) of this AD, accomplish one of the following:

(1) Send the engine mounting frame to the manufacturer for repair at the address specified in paragraph (h) of this AD and accomplish the warm air duct modification or replacement specified in paragraph (b) of this AD. Do not operate the glider until the part is repaired, sent back, and re-installed on the glider; or

(2) Replace the engine mounting frame with a new part of the same design, or an FAA-approved part that has been inspected in accordance with the requirements of paragraph (a) of this AD and is found free of damage.

(e) If damage (abrasions, notches, or chafing) is found during the inspection required by paragraph (a) of this AD, and the damage is more than 0.7 mm in depth as specified in paragraph 3(c) of the Action section of Grob Service Bulletin TM 817-45, dated July 27, 1995, prior to further flight, accomplish one of the following:

(1) Send the engine mounting frame to the manufacturer for repair at the address specified in paragraph (h) of this AD and accomplish the warm air duct modification or replacement specified in paragraph (b) of this AD. Do not operate the glider until the part is repaired, sent back, and re-installed on the glider; or

(2) Replace the engine mounting frame with a new part of the same design, or an FAA-approved part that has been inspected in accordance with the requirements of paragraph (a) of this AD and is found free of damage. Accomplish the warm air duct modification or replacement specified in paragraph (b) of this AD.

(f) 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.

(g) 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, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAAMaintenance 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.

(h) Questions or technical information related to Grob Service Bulletin TM 817-45, dated July 27, 1995, should be directed to Grob-Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen, 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.

(i) The inspection required by this AD shall be done in accordance with Grob Service Bulletin TM 817-45, dated July 27, 1995. 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-Werke GmbH & Co. KG, Unternehmensbereich, Burkhart Grob Flugzeugbau, Flugplatz Mattsies, 86874 Tussenhausen, 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 95-362 Grob, dated September 27, 1995.

(j) This amendment becomes effective December 17, 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 Grob Model G 109B gliders was published in the Federal Register as a notice of proposed rulemaking (NPRM) on September 2, 1998 (63 FR 46714). The NPRM proposed to require inspecting the engine mounting frame for paint scratches and damage (abrasions, notches, or chafing); and repairing any paint scratches, and repairing or replacing any engine mounting frame that is found damaged. Accomplishment of the proposed action as specified in the NPRM would be in accordance with Grob Service Bulletin TM 817-45, dated July 27, 1995.

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.

Cost Impact
The FAA estimates that 29 gliders in the U.S. registry will be affected by the inspection, that it will take approximately 2 workhours per glider to accomplish the inspection, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the inspection on U.S. operators is estimated to be $3,480, or $120 per glider.

If damage is found on the engine mounting frame that is beyond certain limits specified in the service information, the FAA estimates that it will take approximately 13 workhours per glider to accomplish the repair or replacement, at an average labor rate of approximately $60 an hour. Parts cost $200 for repair and $750 for replacement. Based on these figures, the total cost impact of the repair, if necessary, is estimated to be $980 per glider. The total cost impact of the replacement, if necessary, is estimated to be $1,530 per glider.

Compliance Time of This AD
Although damage to the engine mounting frame occurs during flight, this unsafe condition is not a result of the number of times the glider is operated. The chance of this situation occurring is the same for a glider with 10 hours
time-in-service (TIS) as it will be 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 onall gliders in a reasonable time period.

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 actionis 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: