# AD 77-21-09: Aileron Rudder Balance Interconnect Mechanism

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin 188A and 188C
- Effective: November 25, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-3059
- Registered aircraft: 4 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A2688ED3356B9BA58625697500491C76.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-21-09

## The airworthiness directive

77-21-09 LOCKHEED-CALIFORNIA COMPANY: Amendment 39-3059. Applies to Model 188A and 188C airplanes, certificated in all categories.

Compliance is required within 100 hours additional time in service after the effective date of this AD, unless already accomplished.

To prevent possible jamming of the aileron/rudder remove the aileron rudder balance interconnect mechanism, in accordance with instructions given in Lockheed Electra Service Bulletin Alert 88/SB-698, dated September 12, 1977, or later FAA approved revision.

This amendment becomes effective November 25, 1977.

## 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/77-21-09/models.md
Every aircraft: https://openairdocs.org/ad/77-21-09/aircraft.md

Its text cites no advisory circulars or STCs.

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