# AD 48-25-02: Welded Exhaust Muffler

- Type: Airworthiness directive
- Status: Current
- Products: Cessna 120 and 140
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 2,265 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ACB3F0EFC654B0C486256A340060D917.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/48-25-02

## The airworthiness directive

48-25-02 CESSNA: Applies to All 120 and 140 Aircraft Equipped With Cessna Welded Exhaust Muffler Assemblies.

Inspection required each 25 hours of operation.

Remove the carburetor air heater muff and cabin heater muff and inspect the muffler assemblies for any evidence of cracks paying particular attention to the areas of the mufflers and stacks adjacent to where the exhaust stacks and tailpipe are welded to the muffler assembly. The present placard calling for inspection of the mufflers every 100 hours should be revised to call for this inspection every 25 hours. This directive is intended to apply to only those aircraft equipped with exhaust muffler assemblies that are fabricated by welding exhaust stacks to muffler.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-768](https://openairdocs.org/tcds/A-768): Textron Aviation Inc.; names 2 of 2 models: 140, 120

## 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: 2,265 (2,265 by airframe model, 0 by engine model)
- Makers: Cessna 2,265

Models with the most aircraft:

- [Cessna 140](https://openairdocs.org/model/cessna-140): 1,605 aircraft (airframe model)
- [Cessna 120](https://openairdocs.org/model/cessna-120): 660 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/48-25-02/models.md
Every aircraft: https://openairdocs.org/ad/48-25-02/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.