AD 56-20-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
| aircraft | The Boeing Company | DC-4 | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
| aircraft | The Boeing Company | DC3-G102 | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
| aircraft | The Boeing Company | DC3-G102A | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
| aircraft | The Boeing Company | DC3-G103A | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
| aircraft | The Boeing Company | DC3-G202A | Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft |
Unsafe Condition
Crankshaft bending failures due to continuous engine operation between 2310 and 2510 r.p.m.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install a placard on the instrument panel stating 'Avoid Continuous Operation of the Engines between 2310 and 2510 r.p.m.' and mark tachometers with a red radial band in that range.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than December 1, 1956
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Douglas DC3 Series, DC-4, and C54-DC Series aircraft powered with Pratt & Whitney Military R-2000 and Twin Wasp D Series engines.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Propeller Operating Limits
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_56-20-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-20-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft Subject: Propeller Operating Limits Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | DC-4 | DC3-G102 | DC3-G102A | DC3-G103A | DC3-G202A Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 56-20-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-20-05 SUBJECT HEADING: Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-20-05 DOUGLAS: Applies to All DC3 Series, DC-4 and C54-DC Series Aircraft Powered With Pratt & Whitney Military R-2000 and Twin Wasp D Series Engines. Compliance required not later than December 1, 1956. To avoid crankshaft bending failures, the following placard must be placed on the instrument panel in a conspicuous place: "Avoid Continuous Operation of the Engines between 2310 and 2510 r.p.m." The tachometers must be marked with a red radial band in the above range. This supersedes AD 48-03-01, which applied only to DC-4 airplanes. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_56-20-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-20-05 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft Subject: Propeller Operating Limits Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | DC-4 | DC3-G102 | DC3-G102A | DC3-G103A | DC3-G202A Product Type: Aircraft Product Subtype: Large 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: 56-20-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-20-05 SUBJECT HEADING: Airworthiness Directives; DOUGLAS All DC3, DC-4 and C54-DC Series Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-20-05 DOUGLAS: Applies to All DC3 Series, DC-4 and C54-DC Series Aircraft Powered With Pratt & Whitney Military R-2000 and Twin Wasp D Series Engines. Compliance required not later than December 1, 1956. To avoid crankshaft bending failures, the following placard must be placed on the instrument panel in a conspicuous place: "Avoid Continuous Operation of the Engines between 2310 and 2510 r.p.m." The tachometers must be marked with a red radial band in the above range. This supersedes AD 48-03-01, which applied only to DC-4 airplanes. 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.
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