AD 78-08-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | Military R-985 Series | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. A | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. B-4 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. B-5 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB-2 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB-3 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B2 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B3 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T3A | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. TB | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
| engine | Pratt & Whitney Division | Wasp Jr. TB-2 | PRATT & WHITNEY AIRCRAFT Model R985 Engines |
Unsafe Condition
Cylinder head separation from the barrel
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Visually inspect cylinder heads in accordance with Service Bulletin No. 1785. Remove visibly cracked cylinders and those with black combustion leakage before further flight. Inspect all cylinder assemblies prior to installation using ultrasonic testing or equivalent method. Remove cylinders with cracks exceeding specified limits.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 hours time in service after AD effective date for non-ultrasonically inspected cylinders, and within 150 hours time in service for ultrasonically inspected cylinders. Subsequent inspections at intervals not exceeding 100 or 150 hours time in service respectively.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Aircraft Model R985 engines including Military R-985 Series, Wasp Jr. A, B-4, B-5, SB, SB-2, and others as listed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Cylinder Head Separation
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_78-08-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-08-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Model R985 Engines Subject: Cylinder Head Separation Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/02/1978 Make: Pratt & Whitney Division Model: Military R-985 Series | Wasp Jr. A | Wasp Jr. B-4 | Wasp Jr. B-5 | Wasp Jr. SB | Wasp Jr. SB-2 | Was...Show more Product Type: Engine 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: 78-08-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3175 AD NUMBER: 78-08-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Model R985 Engines ACTION: SUMMARY: DATES: Effective May 2, 1978. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-08-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-3175. Applies to Pratt & Whitney Aircraft Wasp, Jr. and R985 model engines. Compliance required as indicated, unless already accomplished. To prevent cylinder head separation from the barrel, perform the following in accordance with Pratt & Whitney Aircraft Service Bulletin No. 1785 or later FAA-approved revision. 1. Visually inspect cylinder heads in accordance with Part B of the bulletin as follows: A. Cylinders not ultrasonically inspected, inspect within 50 hours time in service after effective date of the AD, and thereafter at intervals not to exceed 100 hours time in service. B. Cylinders ultrasonically inspected, inspect within 150 hours time in service after effective date of the AD, and thereafter at intervals not to exceed 150 hours time in service. 2. Remove visibly cracked cylinders and cylinders with black combustion leakage from service before further flight. 3. After the effective date of this AD, inspect all cylinder assemblies, prior to installation on an engine, by the ultrasonic test procedure in Part A of Service Bulletin 1785 or equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region. 4. Remove from service cylinders which show cracks in excess of the limits of Part A, Section IV, of the bulletin. NOTE: Cylinders which have been ultrasonically tested are stamped "UT" and last two digits of year inspected over the intake port. The manufacturer's service bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Division of United Technologies Corp., 400 Main Street, East Hartford, Connecticut 06108. This document may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and FAA Headquarters, 800 Independence Avenue SW., Washington, D.C. 20591. This supersedes AD 76-20-01, Amendment 39-2728. This amendment becomes effective May 2, 1978. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_78-08-07.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 78-08-07 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY AIRCRAFT Model R985 Engines Subject: Cylinder Head Separation Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/02/1978 Make: Pratt & Whitney Division Model: Military R-985 Series | Wasp Jr. A | Wasp Jr. B-4 | Wasp Jr. B-5 | Wasp Jr. SB | Wasp Jr. SB-2 | Was...Show more Product Type: Engine 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: 78-08-07 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-3175 AD NUMBER: 78-08-07 SUBJECT HEADING: PRATT & WHITNEY AIRCRAFT Model R985 Engines ACTION: SUMMARY: DATES: Effective May 2, 1978. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 78-08-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-3175. Applies to Pratt & Whitney Aircraft Wasp, Jr. and R985 model engines. Compliance required as indicated, unless already accomplished. To prevent cylinder head separation from the barrel, perform the following in accordance with Pratt & Whitney Aircraft Service Bulletin No. 1785 or later FAA-approved revision. 1. Visually inspect cylinder heads in accordance with Part B of the bulletin as follows: A. Cylinders not ultrasonically inspected, inspect within 50 hours time in service after effective date of the AD, and thereafter at intervals not to exceed 100 hours time in service. B. Cylinders ultrasonically inspected, inspect within 150 hours time in service after effective date of the AD, and thereafter at intervals not to exceed 150 hours time in service. 2. Remove visibly cracked cylinders and cylinders with black combustion leakage from service before further flight. 3. After the effective date of this AD, inspect all cylinder assemblies, prior to installation on an engine, by the ultrasonic test procedure in Part A of Service Bulletin 1785 or equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, New England Region. 4. Remove from service cylinders which show cracks in excess of the limits of Part A, Section IV, of the bulletin. NOTE: Cylinders which have been ultrasonically tested are stamped "UT" and last two digits of year inspected over the intake port. The manufacturer's service bulletin identified and described in this directive is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Pratt & Whitney Aircraft, Division of United Technologies Corp., 400 Main Street, East Hartford, Connecticut 06108. This document may also be examined at Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and FAA Headquarters, 800 Independence Avenue SW., Washington, D.C. 20591. This supersedes AD 76-20-01, Amendment 39-2728. This amendment becomes effective May 2, 1978. 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.