# AD 78-10-01: Lower Rudder Torque Tube - Type: Airworthiness directive - Status: Current - Products: United Aircraft of Canada Ltd. PT6 series engines (Staggerwing Museum Foundation STC SA1016WE or 2 others) - Effective: May 17, 1978 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-3210 - Registered aircraft: 243 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/470072A30E0DE7DD86256A080072D928.0001 - DRS record last changed: January 21, 2026 - Page: https://openairdocs.org/ad/78-10-01 ## The airworthiness directive 78-10-01 BEECH: Amendment 39-3210. Applies to Beech Models D18C, D18S, E18S, E18S-9700, G18S, H-18, C-45G, TC-45G, C-45H, TC-45J (SNB-5), JRB-6, 3N, 3M and 3NM modified in accordance with STC SA1243WE, SA1016WE, or SA360WE. To preclude failure of the lower rudder torque tube, accomplish the following; unless already accomplished: (a) Within the next 30 days after the effective date of this AD visually inspect the lower rudder torque tube for cracks in the area of the access hole as noted in figure 1 of this AD. (Reference Part Number 452606-7). (b) If no cracks are found, reinspect at intervals not to exceed 30 days from the prior inspection. (c) If cracks are found, prior to further flight: (1) If any crack exceeds 1/2 inch in length, replace with a like serviceable unit, Part Number 452606-7, and reinspect per paragraph (d); (2) If cracks are 1/2 inch or less in length, repair per a method approved by the Chief, Aircraft Engineering Division, FAAWestern Region, and reinspect per paragraph (d); (d) Reinspect at intervals not to exceed 30 days from repair, replacement, or prior inspection. (e) The requirements of this AD may be terminated when modifications are incorporated which are approved by the Chief, Aircraft Engineering Division. Submit proposed modifications schemes to: Chief, Aircraft Engineering Division FAA Western Region P.O. Box 92007 Worldway Postal Center Los Angeles, California 90009 for review and approval. This amendment becomes effective May 17, 1978. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-765](https://openairdocs.org/tcds/A-765): Textron Aviation Inc.; names 13 of 17 models: 3N, E18S-9700, TC-45J, TC-45G, C-45H, C-45G, 3NM, G18S… ## 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: 243 (243 by airframe model, 0 by engine model) - Makers: Beech 243 Models with the most aircraft: - [Beech D18S](https://openairdocs.org/model/beech-d18s): 55 aircraft (airframe model) - [Beech E18S](https://openairdocs.org/model/beech-e18s): 51 aircraft (airframe model) - [Beech C-45H](https://openairdocs.org/model/beech-c-45h): 50 aircraft (airframe model) - [Beech H-18](https://openairdocs.org/model/beech-h-18): 28 aircraft (airframe model) - [Beech G18S](https://openairdocs.org/model/beech-g18s): 23 aircraft (airframe model) - [Beech 3NM](https://openairdocs.org/model/beech-3nm): 11 aircraft (airframe model) - [Beech C-45G](https://openairdocs.org/model/beech-c-45g): 9 aircraft (airframe model) - [Beech E18S-9700](https://openairdocs.org/model/beech-e18s-9700): 7 aircraft (airframe model) - [Beech TC-45J](https://openairdocs.org/model/beech-tc-45j): 5 aircraft (airframe model) - [Beech TC-45G](https://openairdocs.org/model/beech-tc-45g): 2 aircraft (airframe model) - [Beech 3N](https://openairdocs.org/model/beech-3n): 2 aircraft (airframe model) All 13 models: https://openairdocs.org/ad/78-10-01/models.md Every aircraft: https://openairdocs.org/ad/78-10-01/aircraft.md ## Related documents - [STC SA1016WE](https://openairdocs.org/stc/SA1016WE): Installation of United Aircraft of Canada Ltd. PT6 series engines.. Staggerwing Museum Foundation Inc., Named in the applicability - [STC SA1243WE](https://openairdocs.org/stc/SA1243WE): Combined installation of PT6A turboprop engines (per STC SA111WE), tri-gear (per STC SA1016WE), and 'Tradewind' single tail.. Volpar, Inc, Named in the applicability - [STC SA360WE](https://openairdocs.org/stc/SA360WE): PAC Tradewind Modification -(Gross weight modification, empennage modification, installation of tricycle gear, windshield, outer wing fuel tanks, M-4 autopilot, Bendix RS10B fuel injection system, and optional R-985 APS4 engines).. Aerotech Industries, Named in the applicability --- 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.