# AD 57-02-01: Rudder horn attachment - Type: Airworthiness directive - Status: Current - Products: Univair 415-C, 415-CD, 415-D, F-1, 415-E and 415-G - Published: January 1, 1957 - Issued: January 1, 1957 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Registered aircraft: 1,087 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8EC6DCC9E5584A8E86256A4D004BCFD6.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/57-02-01 ## The airworthiness directive 57-02-01 FORNEY (ERCOUPE): Applies to All Models 415-C, -CD, -D, E, G and F-1 Aircraft. Compliance required at every 100 hours. There have been several failures of the rudder horn attachments. Experience has indicated that these failures are attributed to improper ground handling technique rather than to unusual flight loads. The design of the aircraft has placed the fins and rudders at the height which owners and operators have found convenient for pushing or pulling with their hands when moving the airplane in and out of hangers and along the ground. Such handling tactics will subject the surfaces to higher loads than those for which they are designed and should be avoided. The following inspection would be made and corrective action taken when necessary. A load of 10 pounds should be applied to the trailing edge of the rudder while the controls are locked in neutral position. The trailing edge should not deflect more than one-half inch, nor should there be evidence of a clicking noise occurring in the vicinity of the center rudder hinge when the rudder is deflected. If the deflection exceeds 1/2 inch, the control system should be checked to establish that the deflection is in the rudder. Once the deflection has been established as in the rudder or if a clicking noise is heard even though the deflection was less than 1/2 inch, the rudder should be removed and the main spar inspected for cracks. The outboard skin should also be removed sufficiently to inspect the rudder horn attaching structure and the roots of the rudder ribs for cracks or damage. Any parts found cracked or deformed should be replaced. (Except for the cracked rudder ribs, Ercoupe Service Bulletin No. 25, dated July 31, 1953, covers this same subject.) This supersedes AD 53-26-02. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-787](https://openairdocs.org/tcds/A-787): Univair Aircraft Corporation; names 4 of 8 models: F-1, 415-D, 415-G, 415-E - [TCDS A-718](https://openairdocs.org/tcds/A-718): Univair Aircraft Corporation; names 2 of 2 models: 415-CD, 415-C ## 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: 1,087 (1,087 by airframe model, 0 by engine model) - Makers: Ercoupe 793, Engineering & Research 210, Forney 71, Erco 12, Univair 1 Models with the most aircraft: - [Ercoupe 415-C](https://openairdocs.org/model/ercoupe-415-c): 623 aircraft (airframe model) - [Engineering & Research 415-C](https://openairdocs.org/model/engineering-research-415-c): 160 aircraft (airframe model) - [Ercoupe 415-D](https://openairdocs.org/model/ercoupe-415-d): 101 aircraft (airframe model) - [Forney F-1](https://openairdocs.org/model/forney-f-1): 50 aircraft (airframe model) - [Ercoupe 415-CD](https://openairdocs.org/model/ercoupe-415-cd): 48 aircraft (airframe model) - [Engineering & Research 415-D](https://openairdocs.org/model/engineering-research-415-d): 24 aircraft (airframe model) - [Ercoupe 415-E](https://openairdocs.org/model/ercoupe-415-e): 18 aircraft (airframe model) - [Forney 415-C](https://openairdocs.org/model/forney-415-c): 17 aircraft (airframe model) - [Engineering & Research 415-CD](https://openairdocs.org/model/engineering-research-415-cd): 16 aircraft (airframe model) - [Engineering & Research 415-E](https://openairdocs.org/model/engineering-research-415-e): 7 aircraft (airframe model) - [Erco 415-C](https://openairdocs.org/model/erco-415-c): 7 aircraft (airframe model) - [Erco 415-D](https://openairdocs.org/model/erco-415-d): 4 aircraft (airframe model) - [Engineering & Research 415-G](https://openairdocs.org/model/engineering-research-415-g): 3 aircraft (airframe model) - [Ercoupe 415-G](https://openairdocs.org/model/ercoupe-415-g): 3 aircraft (airframe model) - [Forney 415-D](https://openairdocs.org/model/forney-415-d): 2 aircraft (airframe model) - [Forney 415-CD](https://openairdocs.org/model/forney-415-cd): 1 aircraft (airframe model) - [Forney 415-E](https://openairdocs.org/model/forney-415-e): 1 aircraft (airframe model) - [Erco 415-CD](https://openairdocs.org/model/erco-415-cd): 1 aircraft (airframe model) - [Univair 415-D](https://openairdocs.org/model/univair-415-d): 1 aircraft (airframe model) All 19 models: https://openairdocs.org/ad/57-02-01/models.md Every aircraft: https://openairdocs.org/ad/57-02-01/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 CEN09LA291](https://openairdocs.org/ntsb/CEN09LA291), May 12, 2009: Univair Ercoupe (N99811), Brighton, MI, substantial damage. Probable cause: The pilot's failure to attain the proper touchdown point, and his failure to initiate a go-around. --- 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.