# AD 69-26-08: Takeoff Warning System

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin 188A and 188C
- Effective: January 10, 1970
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-904
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/AE0F6AA2A27BF6FB862569750048A055.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/69-26-08

## The airworthiness directive

69-26-08 LOCKHEED: L-188 Series Airplanes. Amdt. 39-904.

Applies to Lockheed L-188 airplanes listed in Lockheed Service Bulletin 88/5B-672, dated 10 November 1969, or later FAA approved revisions, and to any other L-188 airplane which has the Lockheed takeoff warning system installed.

Compliance required as indicated.

To provide for arming the aural takeoff warning system at lower ambient temperatures, and to provide interim placard information to the flight crew on the present ambient temperature at which the system will not be armed, accomplish the following:

  (a) Within 50 hours time in service after the effective date of this AD install a placard in the cockpit in full view of the pilot to read:

"Takeoff aural warning system will not be armed when setting takeoff power at ambient temperatures below 23 degrees F"

This placard may be removed when Item (b) is accomplished.

  (b) Within 3000 hours time in service, unless previously accomplished modify the arming switches installation in the takeoff warning system to provide for arming the switches at about 68 degrees-70 degrees power lever advancement in accordance with Lockheed Service Bulletin 88/SB-672 dated November 10, 1969, or later FAA approved revisions, or an equivalent modification approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective on January 10, 1970.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A22](https://openairdocs.org/tcds/4A22): Lockheed Martin Corporation; names 2 of 2 models: 188A, 188C

## 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: 4 (4 by airframe model, 0 by engine model)
- Makers: Lockheed 4

Models with the most aircraft:

- [Lockheed 188C](https://openairdocs.org/model/lockheed-188c): 3 aircraft (airframe model)
- [Lockheed 188A](https://openairdocs.org/model/lockheed-188a): 1 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/69-26-08/models.md
Every aircraft: https://openairdocs.org/ad/69-26-08/aircraft.md

Its text cites no advisory circulars or STCs.

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