# AD 55-24-01: Corrosion Inspection - Type: Airworthiness directive - Status: Current - Products: Don Luscombe Aviation History Foundation 8, 8A, 8B, 8C, 8D and 8E - Effective: May 22, 1973 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-1640 - Registered aircraft: 1,303 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B1CC8E4CFDA36CF586256CC4006B117D.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/55-24-01 ## The airworthiness directive 55-24-01 LUSCOMBE: Published in 21 FR 9540 on December 4, 1956, and as amended in 22 FR 2416 on April 11, 1957, is further amended by Amendment 39-1565 and 39-1640. Applies to All 8 Series Aircraft Except Model 8-F with Serial Numbers S-1 and Up. To be accomplished by March 1, 1956, and thereafter at intervals not to exceed 12 calendar months from last inspection. Extreme surface corrosion has been found to exist inside the fuselage spar carry through structures P/N 28018 and 28019 of Luscombe Series 8 aircraft, particularly in those airplanes which are located near coastal areas. If allowed to progress, such corrosion could deteriorate the spar carry through members until a structural failure occurred. This corrosion is internal and cannot be detected by an external inspection. Therefore, the inside surfaces of the spar carry through members must be inspected. This may be accomplished by either of the two following acceptable methods: (1) Remove wings from the airplane and also the wing attachment fittings. The ends of both the front and rear spar superstructures will then be open so that an internal inspection of these hat-section members can be made. (2) Use of this method of inspection will not require the removal of the wings from the airplane. One-half inch holes may be drilled through the top wing skin directly over each spar carry through member so that a visual inspection can be made directly into the bottom of the hat sections. The airframe structure had adequate margins of safety in this area so that the existence of the 1/2-inch inspection holes will not impair the structural integrity of the airplane. Five of these 1/2-inch holes should be drilled over each of the spar carry through hat sections, one hole at the middle of each spar carry through, one hole 5 inches from each outboard end of the wing attachment fittings and one hole approximately centrally located between this latter hole and the middle hole. Thiswill provide a distance of approximately 7 1/2 inches between holes and should render it possible to inspect all of the internal surface of the hat-section spar carry through members. After the inspection has been made, the 1/2-inch holes must be covered with a small patch of aircraft fabric doped to the surface of the wing skin or by the insertion of a rubber or neoprene seal plug, or equivalent. This method will also provide a ready means of rechecking the spar carry through members for corrosion during the time of subsequent inspections. If any evidence of corrosion is found to exist, the affected spar carry through member should be removed and replaced with an identical new part. The above inspections may be discontinued if both spar carry through structures are replaced with new parts that are identical to the original and properly anodized and painted to prevent corrosion, or if an equivalent modification is approved by the Chief, Engineering and Manufacturing Branch,FAA Southern Region. Amendment 39-1565 became effective December 2, 1972. This Amendment 39-1640 becomes effective May 22, 1973. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-694](https://openairdocs.org/tcds/A-694): Luscombe Aircraft Corporation; names 6 of 8 models: 8, 8D, 8A, 8B, 8E, 8C ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 1,303 (1,303 by airframe model, 0 by engine model) - Makers: Luscombe 1,301, Luscombe/Ranger Avia 1, Luscombe/Wilder 1 Models with the most aircraft: - [Luscombe 8A](https://openairdocs.org/model/luscombe-8a): 897 aircraft (airframe model) - [Luscombe 8E](https://openairdocs.org/model/luscombe-8e): 326 aircraft (airframe model) - [Luscombe 8C](https://openairdocs.org/model/luscombe-8c): 37 aircraft (airframe model) - [Luscombe 8B](https://openairdocs.org/model/luscombe-8b): 16 aircraft (airframe model) - [Luscombe 8D](https://openairdocs.org/model/luscombe-8d): 14 aircraft (airframe model) - [Luscombe 8](https://openairdocs.org/model/luscombe-8): 11 aircraft (airframe model) - [Luscombe/Wilder 8A](https://openairdocs.org/model/luscombe-wilder-8a): 1 aircraft (airframe model) - [Luscombe/Ranger Avia 8A](https://openairdocs.org/model/luscombe-ranger-avia-8a): 1 aircraft (airframe model) All 9 models: https://openairdocs.org/ad/55-24-01/models.md Every aircraft: https://openairdocs.org/ad/55-24-01/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.