AD 80-20-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 421C | Airworthiness Directives; Cessna Model 421C Airplanes |
Unsafe Condition
The KFC-200 Flight Control System's roll axis hard-over malfunction could cause the airplane to exceed 60 degrees bank angle.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Reset the KFC-200 roll axis slip clutch to 38 ±4 inch-pounds within 25 hours time-in-service after the AD's effective date. Use King Radio Service Sales Installation Bulletin No. 167. If the autopilot is inoperative, airplanes may be flown under FAR 21.197 to a maintenance location.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 25 hours time-in-service after the effective date of this AD
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Affected Aircraft
Cessna Model 421C airplanes (Serial Number 421C0401 and on) with King KFC-200 Flight Control System installed under STC SA1246CE
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
KFC-200 Flight Control System Modification Under STC SA1246CE
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_80-20-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 80-20-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Cessna Model 421C Airplanes Subject: KFC-200 Flight Control System Modification Under STC SA1246CE Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/14/1980 Make: Cessna Aircraft Company Model: 421C Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 80-20-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3937 AD NUMBER: 80-20-06 SUBJECT HEADING: Airworthiness Directives; Cessna Model 421C Airplanes ACTION: SUMMARY: DATES: Effective October 14, 1980. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 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. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_80-20-06.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 80-20-06 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Cessna Model 421C Airplanes Subject: KFC-200 Flight Control System Modification Under STC SA1246CE Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/14/1980 Make: Cessna Aircraft Company Model: 421C Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 80-20-06 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3937 AD NUMBER: 80-20-06 SUBJECT HEADING: Airworthiness Directives; Cessna Model 421C Airplanes ACTION: SUMMARY: DATES: Effective October 14, 1980. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 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. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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