AD 96-19-07

96-19-07 BURKHART GROB LUFT-UND RAUMFAHRT: Priority Letter issued on September 6, 1996. Docket No. 96-CE-50-AD.

Applicability: Models G115C, G115C2, G115D, and G115D2 airplanes (all serial numbers), certificated in any category.

NOTE 1: This AD applies to each airplane 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 airplanes 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 (f) 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 prior to further flight after receipt of this priority letter AD, unless already accomplished.

To prevent loss of control of the airplane caused by excessive speed or aerobatic maneuvers, accomplish the following:

(a) Install, on the limitation placard at the left-hand cabin wall, the airspeed placard that is included with Grob Service Bulletin (SB) 1078-59/2, dated September 2, 1996. This placard reduces the maximum airspeed to 296 kilometers per hour (km/h); equal to 160 knots per hour.

(b) Modify the airspeed indicator glass by accomplishing the following:

(1) Place a red radial line on the indicator glass at 296 km/h (160 knots). The minimum dimensions for this radial line are 0.05 inches wide and 0.30 inches in length.

(2) Place a white 0.05 inch minimum width slippage index mark connecting both the instrument glass and bezel. Locate this slippage index mark so that it does not obscure any airspeed markings.

(c) Install, near the airspeed indicator,the red placard included with Grob SB 1078-59/2 that has the words: "Aerobatic maneuvers are prohibited."

(d) Insert a copy of this AD into the Limitations Section of the airplane flight manual.

(e) 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 airplane to a location where the requirements of this AD can be accomplished.

(f) 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 Division, 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 Aircraft Certification Division.

NOTE 2: Information concerning the existence of approved alternative methodsof compliance with this AD, if any, may be obtained from the Brussels Aircraft Certification Division.

(g) The service information and placards specified in this priority letter may be obtained from Burkhart Grob Luft-und Raumfahrt, D-8939 Mattsies, Germany. This information may also be examined at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

(h) Priority Letter AD 96-19-07, issued September 6, 1996, becomes effective immediately upon receipt.

96-19-07 Burkhart Grob

Events Leading to this Priority Letter
The Federal Aviation Administration (FAA) is currently involved with investigating an in-flight breakup of a Grob Model G115D airplane. Preliminary investigation of the accident reveals that the empennage separated from the airplane. Both crew members were killed in the accident. Involved in the on-going investigation are:

- the FAA;

- the National Transportation Safety Board (NTSB); and

- Grob (the manufacturer of the accident airplane).

Applicable Service Information
Grob has issued Service Bulletin (SB) 1078-59/2, dated September 2, 1996, which specifies (1) installing a placard that restricts the never exceed speed (Vne) of the affected airplanes from 184 knots to 160 knots; (2) installing on the airspeed indicator a red line at 296 km/h (160 knots); and (3) installing a placard that prohibits aerobatic maneuvers. The placards are included in this service bulletin.

The FAA's DeterminationAlthough the on-going investigation of the in-flight breakup of the Grob Model G115D airplane is not complete, the FAA has determined (1) that the actions specified in Grob SB 1078-59/2, dated September 2, 1996, should be accomplished by all owners/operators of Grob Models G115C, G115C2, G115D, and G115D2 airplanes; and (2) airworthiness directive (AD) action should be taken to prevent loss of control of the airplane caused by excessive speed or aerobatic maneuvers. Further rulemaking may be required when the results of the accident investigation are known.

These airplane models are manufactured in Germany and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for the Federal Republic of Germany, is preparing an AD in order to assure the continued airworthiness ofthese airplanes in Germany.

Explanation of the Provisions of this AD
Since an unsafe condition has been identified that is likely to exist or develop on other Grob Models G115C, G115C2, G115D, and G115D2 airplanes of the same type design that are registered for operation in the United States, the FAA has determined that priority letter AD action should be taken. This priority letter AD requires the following:

- installing a placard that restricts the never exceed speed (Vne) of the affected airplane models from 184 knots to 160 knots;

- installing on the airspeed indicator glass a red line at 296 km/h (160 knots);

- installing a placard that prohibits aerobatic maneuvers; and

- placing a copy of this AD in the Limitations Section of the airplane flight manual.

The placards are included with Grob SB 1078-59/2, dated September 2, 1996.

This rule is issued under 49 U.S.C. Section 44701 (formerly section 601 of the Federal Aviation Act of 1958), pursuantto the authority delegated to me by the Administrator, and is effective immediately upon receipt of this priority letter.