AD 62-26-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft |
| aircraft | The Boeing Company | DC-4 | Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft |
Unsafe Condition
Vibration stresses in excess of allowable limits for continuous safe operation occur in Hamilton Standard 23E50/6507-0 propeller blades over a wider range of engine operating speeds than previously determined.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove existing placard covering 1,600-1,700 r.p.m. range and install new placard warning against operation between 1,550-1,750 r.p.m. during flight and 1,550-1,800 r.p.m. on ground with blades off low pitch stops. Mark tachometers with red arc over 1,550-1,750 r.p.m. range. Revise Airplane Flight Manual to incorporate these limitations.
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Compliance Time
within the next 200 hours' time in service after the effective date of this AD
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Affected Aircraft
DOUGLAS All C54-DC Series and DC-4 Aircraft equipped with Pratt & Whitney Twin Wasp Series/R-2000 Series engines and Hamilton Standard 23E50/6507-0 propellers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Operating Restrictions
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_62-26-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 62-26-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft Subject: Operating Restrictions Status: Current Citation: (Federal Register: December 8, 1962) Citation Publish Date: 12/08/1962 Effective Date: 01/08/1963 Make: The Boeing Company Model: C54-DC | DC-4 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 62-26-01 CITATION: [Federal Register: December 8, 1962] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 62-26-01 SUBJECT HEADING: Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft ACTION: SUMMARY: DATES: Effective January 8, 1963. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 62-26-01 DOUGLAS: Amdt. 517 Part 507 Federal Register December 8, 1962. Applies to All C54-DC Series and DC-4 Aircraft Equipped With Pratt & Whitney Aircraft Twin Wasp Series and R-2000 Series Engines and Hamilton Standard 23E50/6507-0 Propellers. Compliance required within the next 200 hours' time in service after the effective date of this AD. Recent resurveys of 23E50/6507-0 propeller blade vibration stresses have shown that vibration stresses in excess of allowable limits for continuous safe operation occur over a wider range of engine operating speeds than was determined by previous surveys. To prevent possible blade failures due to exceeding allowable stress limits within this speed range, the following is required: (a) Remove the existing placard covering the 1,600 to 1,700 r.p.m. range and install a new placard in full view of the pilot to read: "During flight, avoid operation between 1,550 and 1,750 r.p.m. During ground running, avoid operation between 1,550 and 1,800 r.p.m. when the blades are off the low pitch stops." (b) Mark the tachometers with a red arc over the 1,550 and 1,750 r.p.m. range. (c) Revise the operating limitations section of the FAA approved Airplane Flight Manual to incorporate the limitations in (a) and (b). NOTE: The other restricted operating speed range between 2,310 and 2,510 r.p.m. required by AD 56-20-05 still remains in effect. For the purpose of this directive, a single placard reading: "During flight, avoid operation between 1,550 and 1,750 r.p.m. and between 2,310 and 2,510 r.p.m.", in the first sentence, may be installed if desired. Similar wording may be used for the FAA approved Airplane Flight Manual. This directive effective January 8, 1963. FOOTER:
Document Text
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AD Final Rules - DRS_62-26-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 62-26-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft Subject: Operating Restrictions Status: Current Citation: (Federal Register: December 8, 1962) Citation Publish Date: 12/08/1962 Effective Date: 01/08/1963 Make: The Boeing Company Model: C54-DC | DC-4 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: 62-26-01 CITATION: [Federal Register: December 8, 1962] PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 62-26-01 SUBJECT HEADING: Airworthiness Directives; DOUGLAS All C54-DC Series and DC-4 Aircraft ACTION: SUMMARY: DATES: Effective January 8, 1963. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 62-26-01 DOUGLAS: Amdt. 517 Part 507 Federal Register December 8, 1962. Applies to All C54-DC Series and DC-4 Aircraft Equipped With Pratt & Whitney Aircraft Twin Wasp Series and R-2000 Series Engines and Hamilton Standard 23E50/6507-0 Propellers. Compliance required within the next 200 hours' time in service after the effective date of this AD. Recent resurveys of 23E50/6507-0 propeller blade vibration stresses have shown that vibration stresses in excess of allowable limits for continuous safe operation occur over a wider range of engine operating speeds than was determined by previous surveys. To prevent possible blade failures due to exceeding allowable stress limits within this speed range, the following is required: (a) Remove the existing placard covering the 1,600 to 1,700 r.p.m. range and install a new placard in full view of the pilot to read: "During flight, avoid operation between 1,550 and 1,750 r.p.m. During ground running, avoid operation between 1,550 and 1,800 r.p.m. when the blades are off the low pitch stops." (b) Mark the tachometers with a red arc over the 1,550 and 1,750 r.p.m. range. (c) Revise the operating limitations section of the FAA approved Airplane Flight Manual to incorporate the limitations in (a) and (b). NOTE: The other restricted operating speed range between 2,310 and 2,510 r.p.m. required by AD 56-20-05 still remains in effect. For the purpose of this directive, a single placard reading: "During flight, avoid operation between 1,550 and 1,750 r.p.m. and between 2,310 and 2,510 r.p.m.", in the first sentence, may be installed if desired. Similar wording may be used for the FAA approved Airplane Flight Manual. This directive effective January 8, 1963. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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