| AD Number | 85-12-10 | Status | Active |
| Effective Date | July 22, 1985 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-5079 |
| Product Type | ["Aircraft"] | Product Subtype | ["Glider"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Slingsby Aviation Ltd. |
| Model(s) | Type T.53.B. |
85-12-10 SLINGSBY SAILPLANES: Amendment 39-5079. Applies to Slingsby T.53.B gliders certificated in all categories.
Compliance is required as indicated unless already accomplished.
To prevent structural failure due to fatigue cracks, accomplish the following:
(a) Within the next 10 hours time in service after the effective date of this AD, install a placard on the instrument panel in full view of the pilot reading: "CLOUD FLYING AND AEROBATIC MANEUVERS PROHIBITED."
(b) (1) Within the next 10 hours time in service after the effective date of this AD, and thereafter at intervals not to exceed 5 hours time in service from the last inspection, visually inspect the welded frame P/N T53B-1079, which joins the forward spar member with the rear spar member of the fuselage center section, for cracks at the forward extremity of the lower two tubes where they are welded to the thin vertical channels.
(2) Within the next 10 hours time in service after the effectivedate of this AD, and thereafter at intervals not to exceed 5 hours time in service from the last inspection, inspect the two aft brackets (welded brackets - P/N T53B-10-168, Issue 1-4; riveted brackets - P/N T53B-10-168, Issue 5) that attach the wing center section to fuselage frame No. 6 for fatigue cracks using the dye penetrant crack detection method in accordance with Slingsby Engineering Limited Technical Instruction No. 100/T53, Issue 1, dated October 20, 1981, or an FAA- approved equivalent.
(c) If cracks are found as a result of the inspections required by paragraph (b)(1), prior to further flight, modify the tubular structure in accordance with Slingsby Sailplanes Technical Instruction No. 68, dated August 14, 1974, or an FAA-approved equivalent.
(d) If cracks are found as a result of the inspections required by paragraph (b)(2), prior to further flight, replace the aft two brackets in accordance with Slingsby Sailplanes Technical Instruction No. 70, dated September11, 1974, or an FAA-approved equivalent, and Slingsby Engineering Limited Technical Instruction No. 100/T53, Issue 1, dated October 20, 1981, or an FAA-approved equivalent.
(e) The placard required by paragraph (a) may be removed, and the inspections required by paragraph (b) may be discontinued, after the modification of the tubular structure, in accordance with Slingsby Sailplanes Technical Instruction No. 68, dated August 14, 1974, or an FAA-approved equivalent, has been accomplished, and when the aft two brackets have been replaced in accordance with Slingsby Sailplanes Technical Instruction No. 70, dated September 11, 1974, or an FAA-approved equivalent, and Slingsby Engineering Limited Technical Instruction No. 100/T53, Issue 1, dated October 20, 1981, or an FAA-approved equivalent.
(f) Within the next 25 hours time in service after the effective date of this AD, unless already accomplished within the past 75 hours time in service, and thereafter at intervals not to exceed 100 hours time in service from the last inspection, comply with the following:
(1) Dye penetrant inspect the metal lugs P/N T53B-10-115, and channel section P/N T53B-10-118, on fuselage frame No. 6, in accordance with Slingsby Engineering Limited Technical Instruction No. 100/T53, Issue 1, dated October 20, 1981, or an FAA- approved equivalent.
(2) If cracks are found as a result of the inspections required by paragraph (f)(1) of this AD, prior to further flight, replace the metal lugs and/or channel section in accordance with Slingsby Engineering Limited Technical Instruction No. 100/T53, Issue 1, dated October 20, 1981, or FAA-approved equivalent.
Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Brussels Aircraft Certification Office, AEU-100, Europe, Africa, and Middle East Office, FAA, c/o American Embassy, 1000 Brussels, Belgium, telephone 513.38.30 ext. 2710.
Slingsby Sailplane Technical Instruction No. 70 dated September 11, 1974, Slingsby Sailplane Technical Instruction No. 68 dated August 14, 1974, and Slingsby Engineering Limited Technical Instruction dated October 20, 1981, are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Slingsby Engineering Limited, Ings Lane, Kirbymoorside, York, Y06, 6EZ, England. These documents also may be examined at the Office of the Regional Counsel, 12 New England Executive Park, Burlington, Massachusetts 01803.
This AD supersedes Amendment 39-2308 (40 FR 32318), AD 75-17-07.
This Amendment 39-5079 becomes effective on July 22, 1985.