# AD 48-18-04: Supercharger Bearing Thermocouple

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed 49-46
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 1 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ECB2EAB4F6C940AE8625696D0071A454.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/48-18-04

## The airworthiness directive

48-18-04 LOCKHEED: Applies to Model 49-46 Aircraft Serial Numbers 1975 Through 1980 and 2021 Through 2088.

Compliance with the following was required prior to September 19, 1947, by direct notification of operators.

Add thermocouple to cabin supercharger bevel gear housing, and direct reading indicator in cockpit to record temperatures of the rear supercharger universal coupling support bearing.

(LAC Service Bulletin 49/SB-390 covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-763](https://openairdocs.org/tcds/A-763): Lockheed Martin Aeronautics Company; names 1 of 6 models: 49-46

## 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: 1 (1 by airframe model, 0 by engine model)
- Makers: Lockheed 1

Models with the most aircraft:

- [Lockheed 49-46](https://openairdocs.org/model/lockheed-49-46): 1 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/48-18-04/models.md
Every aircraft: https://openairdocs.org/ad/48-18-04/aircraft.md

Its text cites no advisory circulars or STCs.

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