AD 95-08-13

This amendment adopts a new airworthiness directive (AD) that applies to B. Grob Flugzeugbau (Grob) Model G109B gliders. This action requires replacing the elevator inner hinges with hinges of improved design. Two occurrences where the elevator inner hinges separated from the elevator prompted the required action. The actions specified by this AD are intended to prevent failure of these hinges because of delamination or corrosion, which, if not detected and corrected, could lead to loss of control of the glider.

Final rule

95-08-13 B. GROB FLUGZEUGBAU: Amendment 39-9202; Docket No. 94-CE-30-AD.

Applicability: Model G109B gliders, serial numbers 6200 through 6445, 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 use the authority provided in paragraph (c) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of anymodification, alteration, or repair remove any glider from the applicability of this AD.

Compliance: Required within the next 25 hours time-in-service after the effective date of this AD or within the next 6 calendar months after the effective date of this AD, whichever occurs first, unless already accomplished.

To prevent failure of the elevator inner hinges because of delamination or corrosion, which, if not detected and corrected, could lead to loss of control of the glider, accomplish the following:

(a) Replace the elevator inner hinges (2) with hinges of improved design, part number 109B-3550, in accordance with Grob Repair Instructions No. 817-25 for Service Bulletin TM 817-25, dated November 9, 1987.

NOTE 2: The service instructions of this AD call for "the execution of the instructions to be certified in the log-book by an authorized inspector class 3." This type of inspector is not applicable in the United States and the person accomplishing the AD is as outlined in part 43 of the Federal Aviation Regulations (14 CFR part 43). This is not a change over normal AD procedures.

(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 gliders 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, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(d) The replacement required by this AD shallbe done in accordance with Grob Repair Instructions No. 817-25 for Service Bulletin TM 817-25, dated November 9, 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 B. Grob Flugzeugbau, D-8939 Mattsies, 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 June 2, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to Grob Model G109B gliders was published in the Federal Register on January 10, 1995 (59 FR 2555). The action proposed to require replacing the elevator inner hinges with hinges of improved design. Accomplishment of the proposed action would be in accordance with Grob Repair Instructions No. 817-25 for Service Bulletin TM 817-25, dated November 9, 1987.

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 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 or add any additional burden upon the public than was already proposed.

The unsafe condition referenced in this AD is caused by both stress loads and corrosion. Stress loads are a direct result of glider usage. Corrosion can then develop regardless of whether the glider is utilized in flight or is on the ground. With this in mind, the FAA has determined that the compliance time of this AD should be in both calendar time and hours time-in-service (TIS).

The FAA estimates that 30 gliders in the U.S. registry will be affected by this proposed AD, that it will take approximately 8 workhours per glider to accomplish the required action, and that the average labor rate is approximately $60 an hour. Parts will be provided by the manufacturer at no cost to the operator. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $14,400. This figure is based on the assumption thatno affected glider owner/operator has accomplished the proposed replacement of the elevator inner hinges.

Grob has informed the FAA that approximately 20 of the affected gliders already have the required replacement incorporated. With this in mind, the cost impact upon the public of the required action would be reduced from $14,400 to $5,280.

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; 49U.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: