Airworthiness Directive · Amendment 39-17451 · Wing
Slingsby Sailplanes Ltd. Sailplanes
This AD applies to Slingsby Sailplanes Ltd. Models Dart T.51, Dart T.51/17, and Dart T.51/17R sailplanes, all serial numbers, that are:
(1) Equipped with aluminum alloy spar booms; and
(2) certificated in any category.
We are superseding an existing airworthiness directive (AD) for all Slingsby Sailplanes Ltd. Models Dart T.51, Dart T.51/17, and Dart T.51/17R sailplanes equipped with aluminum alloy spar booms. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as an incident of glue joint failure on a starboard wing caused by water entering the area of the airbrake box that resulted in delamination and corrosion in the area of the aluminum alloy spar booms and the wing attach fittings. We are issuing this AD to require actions to address the unsafe condition on these products.
Unless already done, do the following actions specified in paragraphs (f)(1) and (f)(2) of this AD:
(1) Within the next 6 calendar months after December 14, 1998 (the effective date retained from AD 98-22-15, Amendment 39-10863 (63 FR 58624, November 2, 1998)), inspect the aluminum alloy spar booms and the wing attach fittings for delamination or corrosion damage following the ACTION section of Slingsby Aviation Ltd. Technical Instruction T.I. No. 109/T51, Issue No. 2, dated October 7, 1997, or the ACTION section of Slingsby Aviation Ltd. Technical Instruction T.I. No. 109/T51, Issue 3, dated August 21, 2000.
Note 1 to paragraph (f)(1) of this AD: Slingsby Aviation Ltd. Technical Instruction T.I. No. 109/T51, Issue No. 2, dated October 7, 1997, and T.I. No. 109/T51, Issue 3, dated August 21, 2000, include guidance to determine whether an affected sailplane is equipped with aluminum alloy spar booms.
(2) If any corrosion or delamination damage is found during the inspection required by paragraph (f)(1) of this AD, before further flight, contact the manufacturer at the address specified in paragraph (j)(5) of this AD to obtain an FAA-approved repair scheme and incorporate the repair.
Unless already done, do the following actions specified in paragraphs (g)(1) and (g)(2) of this AD:
(1) Within 5 years after the last inspection required by AD 98-22-15, Amendment 39-10863 (63 FR 58624, November 2, 1998) and repetitively thereafter at intervals not to exceed 12 months, using an endoscope, inspect the aluminum alloy spar booms and the wing attach fittings for delamination or corrosion damage following paragraph 11 of the ACTION section of Slingsby Aviation Ltd. Technical Instruction T.I. No. 109/T51, Issue 3, dated August 21, 2000.
(2) If any corrosion or delamination damage is found during any inspection required by paragraph (g)(1) of this AD, before further flight, contact the manufacturer at the address specified in paragraph (j)(5) of this AD to obtain an FAA-approved repair scheme and incorporate the repair.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
