- Effective
- October 14, 1980
- Model
- 421C
- Data sheet
- TCDSA7CE
- Registered aircraft
- 496 matched by model
- Product
- Aircraft · Small airplane
- Amendment
- 39-3937
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 | 21 KB | 26dc84d4…e40f750 | FAA DRS (API key needed) |
On this page
The airworthiness directive
80-20-06 CESSNA: Amendment 39-3937. Applies to Model 421C airplanes (Serial Number 421C0401 and on) having King KFC-200 Flight Control System installed under Supplemental Type Certificate SA1246CE.
COMPLIANCE: Required as indicated unless already accomplished.
To prevent the airplane from exceeding 60 degrees bank angle in the event of a roll axis hard-over malfunction, accomplish the following:
A) Within the next 25 hours time-in-service after the effective date of this AD, reset the KFC-200 roll axis slip clutch from 60 plus or minus 6 inch-pounds to 38 plus or minus 4 inch-pounds in accordance with the instructions contained in King Radio Service Sales Installation Bulletin No. 167 dated August 4, 1980.
B) Airplanes may be flown in accordance with FAR 21.197 to a location where the maintenance required by this AD may be performed provided the autopilot is inoperative.
C) Any equivalent method of compliance must be approved by the Chief, Aircraft Certification Program, Federal Aviation Administration, Room 238, Terminal Building No. 2299, Mid-Continent Airport, Wichita, Kansas 67209.
This amendment becomes effective October 14, 1980.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 496
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1975 | 18 |
|---|---|
| 1976 | 53 |
| 1977 | 51 |
| 1978 | 37 |
| 1979 | 36 |
| 1980 | 33 |
| 1981 | 36 |
| 1982 | 18 |
| 1983 | 2 |
| 1984 | 8 |
| 1985 | 3 |
201 with no year recorded