# AD 80-24-02: Aileron Mount Structures - Type: Airworthiness directive - Status: Current - Products: Viking Air DHC-2 Mk.I, DHC-2 Mk.II and DHC-2 Mk.III - Effective: November 20, 1980 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-3973 - Registered aircraft: 140 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F4CDEC139216173786256A4E0058147E.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/80-24-02 ## The airworthiness directive 80-24-02 DEHAVILLAND: Amendment 39-3973. Applies to all model DHC-2 aircraft. Compliance is required as indicated. To preclude wing/aileron flutter due to cracks and loose rivets in the aileron differential mount structures (located in the forward cabin roof), when combined with loose control cables or improperly balanced ailerons, accomplish the following: (a) On airplanes in which the aileron differential mount structure incorporates channel P/N C2CF623ND, within the next 100 hours in service, unless already accomplished within the last 500 hours in service, and thereafter at intervals not exceeding 600 hours in service, inspect channel P/N C2CF623ND and angles P/N C2CF627ND/628ND for damage, cracks and loose rivets. Repair, if necessary in accordance with DeHavilland Aircraft of Canada, Limited, Engineering Service Bulletin Series "B". No. 28 supplement dated March 22, 1963, or an FAA approved equivalent. (b) On airplanes in which the aileron differential mount structure incorporates channel P/N C2CF1265ND, within the next 100 hours in service, unless already accomplished, inspect, repair and modify in accordance with the DeHavilland Aircraft of Canada, Limited, Engineering Bulletin Series "B", No. 28 dated March 1, 1963, or an FAA approved equivalent. (c) On all airplanes, within the next 100 hours in service, unless already accomplished, ensure that the aileron cable tension is in accordance with the DeHavilland Aircraft of Canada, Limited, Service Bulletin No. 2/27, Revision A, dated August 15, 1980, and that the aileron is balanced within the limits contained in the DHC-2 repair manual, or an FAA- approved equivalent. (d) Equivalent inspections, alterations and replacement parts must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region. (e) Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch,FAA, Eastern Region, may adjust the compliance times specified in this AD. This amendment supersedes AD 63-16-02. This amendment is effective November 20, 1980. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-806](https://openairdocs.org/tcds/A-806): De Havilland Aircraft of Canada Limited; names 3 of 3 models: DHC-2 Mk.II, DHC-2 Mk.III, DHC-2 Mk.I ## 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: 140 (140 by airframe model, 0 by engine model) - Makers: Dehavilland 135, Dehavilland Acft Of Canada 3, Dehavilland-Shawano 2 Models with the most aircraft: - [Dehavilland DHC-2 MK. I(L20A)](https://openairdocs.org/model/dehavilland-dhc-2-mk-i-l20a): 91 aircraft (airframe model) - [Dehavilland DHC 2 MK III](https://openairdocs.org/model/dehavilland-dhc-2-mk-iii): 24 aircraft (airframe model) - [Dehavilland DHC-2 MK.I](https://openairdocs.org/model/dehavilland-dhc-2-mk-i): 20 aircraft (airframe model) - [Dehavilland Acft Of Canada DHC-2 MK I](https://openairdocs.org/model/dehavilland-acft-of-canada-dhc-2-mk-i): 3 aircraft (airframe model) - [Dehavilland-Shawano DHC-2 MK.I](https://openairdocs.org/model/dehavilland-shawano-dhc-2-mk-i): 2 aircraft (airframe model) All 5 models: https://openairdocs.org/ad/80-24-02/models.md Every aircraft: https://openairdocs.org/ad/80-24-02/aircraft.md Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB ANC05LA046](https://openairdocs.org/ntsb/ANC05LA046), Mar 7, 2005: de Havilland DHC-2 (N3307S), Talkeetna, AK, substantial damage. Probable cause: Aerodynamic flutter of the ailerons during normal cruise flight due to their improper maintenance/balancing, which resulted in structural damage to the airplane's wings. --- 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.