AD 54-21-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | AC | Diaphragm Type Fuel Pumps | Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines |
| appliance | AC | Diaphragm Type Fuel Pumps | Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines |
Unsafe Condition
Severe fuel leakage in flight caused by loosening of AC fuel pump surge chambers due to inadequate safetying of the sediment bowl and surge chamber.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect sediment bowl cap screw and surge chamber for adequate safetying. If not safetied, lockwiring or equivalent must be accomplished in accordance with good aircraft practice, such as per Lycoming Service Bulletin No. 174.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
as soon as possible but not later than November 30, 1954
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All aircraft powered by Continental, Aircooled, or Lycoming engines equipped with AC Diaphragm Type Fuel Pumps.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
AC Diaphragm Type Fuel Pumps
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_54-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 54-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Contine...Show more Subject: AC Diaphragm Type Fuel Pumps Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: AC Model: Diaphragm Type Fuel Pumps Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 54-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 54-21-01 SUBJECT HEADING: Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 54-21-01 AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines Which Are Equipped With AC Diaphragm Type Fuel Pumps. Compliance required as soon as possible but not later than November 30, 1954. The occurrence of severe fuel leakage in flight, caused by loosening of AC fuel pump surge chambers, has revealed the existence of AC fuel pumps not adequately safetied to prevent loosening of the sediment bowl and the surge chamber. The following should be accomplished: 1. Inspect sediment bowl cap screw and surge chamber (if there is one) for adequate safetying. 2. If not safetied, lockwiring or equivalent must be accomplished in accordance with good aircraft practice. One acceptable method of safetying is described by Lycoming Service Bulletin No. 174. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_54-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 54-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Contine...Show more Subject: AC Diaphragm Type Fuel Pumps Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: AC Model: Diaphragm Type Fuel Pumps Product Type: Appliance Product Subtype: Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 54-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 54-21-01 SUBJECT HEADING: Airworthiness Directives; AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 54-21-01 AC DIAPHRAGM TYPE FUEL PUMPS: Applies to All Aircraft Powered by Continental, Aircooled or Lycoming Engines Which Are Equipped With AC Diaphragm Type Fuel Pumps. Compliance required as soon as possible but not later than November 30, 1954. The occurrence of severe fuel leakage in flight, caused by loosening of AC fuel pump surge chambers, has revealed the existence of AC fuel pumps not adequately safetied to prevent loosening of the sediment bowl and the surge chamber. The following should be accomplished: 1. Inspect sediment bowl cap screw and surge chamber (if there is one) for adequate safetying. 2. If not safetied, lockwiring or equivalent must be accomplished in accordance with good aircraft practice. One acceptable method of safetying is described by Lycoming Service Bulletin No. 174. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.