# AD 93-20-01: Engine Electronic Fuel Control Wiring - Type: Airworthiness directive - Status: Current - Products: Textron 400A and 400T - Effective: November 2, 1993 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-8708 - Docket: 93-NM-153-AD - Registered aircraft: 299 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/EDCAB51A5C7CED2586256A09005E3F2E.0001 - DRS record last changed: January 21, 2026 - Page: https://openairdocs.org/ad/93-20-01 ## The airworthiness directive 93-20-01 BEECH AIRCRAFT CORPORATION: Amendment 39-8708. Docket 93-NM-153-AD. Applicability: Model 400A airplanes having serial numbers RK-45, RK-49 through RK-77 inclusive, and RK-79; and Model 400T (military T-1A) airplanes having serial numbers TT-01 through TT-42 inclusive, and TT-44; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent smoke and/or fire in the cockpit, accomplish the following: (a) Within 25 hours time-in-service after the effective date of this AD, accomplish paragraphs (a)(1), (a)(2), and (a)(3) of this AD. (1) Perform a general visual inspection to verify that the wiring of the engine electronic fuel control (EFC) start circuit has been installed properly, in accordance with Beechcraft Mandatory Service Bulletin 2520, dated August 1993. If the wiring has been installed improperly, prior to further flight, modify the wiring in the engine EFC start circuit in accordance with the service bulletin. (2) Install a non-conductive sheet, part number 132-530027-13, on the sidewall upholstery in accordance with Beechcraft Mandatory Service Bulletin 2520, dated August 1993. (3) Perform a general visual inspection to verify the proper positioning of the end terminals on wire P147D6, in accordance with Beechcraft Safety Communique 400-101, dated July 1993. If the end terminals have been positioned improperly, prior to further flight, reposition the end terminals on wire P147D6 in accordance with the communique. NOTE: While accessing the main circuit panel to comply with the inspections required by this paragraph, as a convenience, operators should verify that moisture (insulator) shields, part numbers 45A88859-11 and 45A88859-31, are installed, in accordance with BEECHCRAFT Beechjet 400/400A Maintenance Manual, Chapter 24-50-00. If any shield is missing, the FAA recommends that it be replaced with an appropriate shield at the next scheduled maintenance service. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO. NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO. (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (d) The inspection and modification of wiring, and the installation of the non-conductive sheet, shall be done in accordance with Beechcraft Mandatory Service Bulletin 2520, dated August 1993. The inspection and repositioning of the endterminals on wire P147D6 shall be done in accordance with Beechcraft Safety Communique 400-101, dated July 1993. (The issue dates of these service documents are indicated only on page 1 of each document; no other pages of the documents are dated.) This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Beech Aircraft Corporation, Commercial Services Department, P.O. Box 85, Wichita, Kansas 67201-0085. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at FAA, Small Airplane Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (e) This amendment becomes effective on November 2, 1993. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A16SW](https://openairdocs.org/tcds/A16SW): Textron Aviation Inc.; names 2 of 4 models: 400A, 400T ## 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: 299 (299 by airframe model, 0 by engine model) - Makers: Raytheon 216, Beech 44, Hawker Beechcraft 39 Models with the most aircraft: - [Raytheon 400A](https://openairdocs.org/model/raytheon-400a): 216 aircraft (airframe model) - [Beech 400A](https://openairdocs.org/model/beech-400a): 43 aircraft (airframe model) - [Hawker Beechcraft 400A](https://openairdocs.org/model/hawker-beechcraft-400a): 39 aircraft (airframe model) - [Beech 400T](https://openairdocs.org/model/beech-400t): 1 aircraft (airframe model) All 5 models: https://openairdocs.org/ad/93-20-01/models.md Every aircraft: https://openairdocs.org/ad/93-20-01/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.