- Model
- Navion B
- Data sheet
- TCDSA-782
- Registered aircraft
- 113 matched by model
- Product
- Aircraft · Small airplane
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 19 KB | 5f449a2a…a8b297e | FAA DRS (API key needed) |
On this page
The airworthiness directive
56-27-04 NAVION: Applies to B Type Aircraft Equipped with Reading Aviation Service Inc. or Hackenberk Sales and Service Downdraft Cooling Kit Installations.
Compliance required not later than July 1, 1957.
Engine cooling tests conducted subsequent to the installation of these kits reveal that cylinder head and oil temperature values can exceed established limits. To prevent serious damage to the engines in these aircraft due to overheating, one of the following alternate actions is necessary.
1. Remove Reading Aviation Service Inc. or Hackenberg Aviation Sales Service downdraft cooling kit and return aircraft to the original Ryan cooling configuration, or
2. Modify the Reading or Hackenberg engine cooling kit in accordance with Reading Aviation Service Inc. Service Bulletin No. 1 dated July 26, 1956.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 113
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1946 | 1 |
|---|---|
| 1947 | 2 |
| 1950 | 46 |
| 1951 | 31 |
| 1952 | 1 |
32 with no year recorded