# AD 93-01-01: Ohm Readings Inspection

- Type: Airworthiness directive
- Status: Current
- Products: Viking Air DHC-7-1, DHC-7-100, DHC-7-101, DHC-7-102 and DHC-7-103
- Effective: February 25, 1993
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-8454
- Docket: 92-NM-133-AD
- Registered aircraft: 7 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8731AC7157C4D88786256A220061A865.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/93-01-01

## The airworthiness directive

93-01-01 DE HAVILLAND, INC.: Amendment 39-8454. Docket 92-NM-133-AD.

Applicability: Model DHC-7 series airplanes; serial numbers 3 and subsequent, having Modification No. 7/2093 installed, except airplanes fitted with Customer Special Installation 78358 (flap indication rework); certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent a takeoff with an incorrect flap indication, which could lead to insufficient lift and increased takeoff distance, resulting in reduced controllability of the airplane, accomplish the following:

  (a) Within 60 days after the effective date of this AD, perform a one-time inspection to detect incorrect ohm readings of the flap position trim control box assembly, in accordance with paragraph III. of de Havilland Alert Service Bulletin S.B. A7-27-86, dated December 19, 1991. If any discrepancies are detected, prior to further flight, modify the assembly in accordance with the service bulletin.

  (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, New York Aircraft Certification Office (ACO), FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York 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 shall be done in accordance with de Havilland Alert Service Bulletin S.B. A7-27-86, dated December 19, 1991. 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 de Havilland, Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

  (e) This amendment becomes effective on February 25, 1993.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20EA](https://openairdocs.org/tcds/A20EA): De Havilland Aircraft of Canada Limited; names 5 of 5 models: DHC-7-101, DHC-7-103, DHC-7-102, DHC-7-100, DHC-7-1

## 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: 7 (7 by airframe model, 0 by engine model)
- Makers: Dehavilland 7

Models with the most aircraft:

- [Dehavilland DHC-7-102](https://openairdocs.org/model/dehavilland-dhc-7-102): 5 aircraft (airframe model)
- [Dehavilland DHC-7-103](https://openairdocs.org/model/dehavilland-dhc-7-103): 2 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/93-01-01/models.md
Every aircraft: https://openairdocs.org/ad/93-01-01/aircraft.md

Its text cites no advisory circulars or STCs.

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