# AD 78-23-06: Stall Warning System

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A) and 6 more
- Effective: December 11, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-3343
- Registered aircraft: 13 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CB9515C34CC8B24D862569CA0050FE34.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-23-06

## The airworthiness directive

78-23-06 MCDONNELL DOUGLAS: Amendment 39-3343. Applies to McDonnell Douglas DC-9-10, -20, -30, -40, -50 series airplanes, including the military versions, all serial numbers, certificated in all categories.

Compliance is required within one year after the effective date of this AD.

To reduce the probability of an unnecessary rejected takeoff due to a false stall warning just after initiation of rotation, modify the stall warning system by extending the time delay to four seconds between nose gear lift-off and the initiation of stall warning, by accomplishing the following:

  (a) Modify the stall warning circuitry in accordance with McDonnell Douglas DC-9 Service Bulletin 34-131 dated January 10, 1978.

NOTE: Service Bulletin 34-131 dated January 10, 1978, is the only version of this service bulletin suitable for compliance with paragraph (a) of this AD.

  (b) Equivalent modifications, procedures, or revisions may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

  (c) Special flight permits may be issued in accordance with FAR's 21.197 and 21.199 to operate airplanes to a base for accomplishment of the modification required by this AD.

This amendment becomes effective December 11, 1978.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 15 of 25 models: DC-9-12, DC-9-15F, DC-9-41, DC-9-13, DC-9-34F, DC-9-33F, DC-9-11, DC-9-51…

## 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: 13 (13 by airframe model, 0 by engine model)
- Makers: Mcdonnell Douglas 8, Douglas 5

Models with the most aircraft:

- [Mcdonnell Douglas DC-9-15F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-15f): 3 aircraft (airframe model)
- [Mcdonnell Douglas DC-9-33F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-33f): 3 aircraft (airframe model)
- [Douglas DC9-15](https://openairdocs.org/model/douglas-dc9-15): 1 aircraft (airframe model)
- [Douglas DC-9-15F](https://openairdocs.org/model/douglas-dc-9-15f): 1 aircraft (airframe model)
- [Douglas DC-9-21](https://openairdocs.org/model/douglas-dc-9-21): 1 aircraft (airframe model)
- [Douglas DC-9-32F](https://openairdocs.org/model/douglas-dc-9-32f): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-9-32](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-9-32F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32f): 1 aircraft (airframe model)
- [Douglas DC-9-33F](https://openairdocs.org/model/douglas-dc-9-33f): 1 aircraft (airframe model)

All 9 models: https://openairdocs.org/ad/78-23-06/models.md
Every aircraft: https://openairdocs.org/ad/78-23-06/aircraft.md

Its text cites no advisory circulars or STCs.

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