AD 56-06-02
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | Double Wasp CA15 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CA17 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CA18 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CA19 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CA3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CA5 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CB16 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CB17 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CB3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp CB4 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Double Wasp R2800-97 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet A-1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet A-2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet A-3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet B | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet B1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet B1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S1B1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S1B1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S1E-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S1E2-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S1E3-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S2B1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S2B1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S2E-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet S3B1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Hornet SB-1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | J60-P-5B | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT12A-6 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT12A-6A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT12A-8 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3C-12 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3C-4 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3C-6 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3C-7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC6 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1-MC7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1A-MC6 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-1A-MC7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-3B | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-3C | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-5A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT3D-7A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-10 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-11 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-12 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-5 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | JT4A-9 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Military R-1340 Series | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Military R-1830 Series | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Military R-2000 Series | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Military R-2800 Series | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Military R-985 Series | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Pratt & Whitney Models (all) | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp 2SD-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp 2SD1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp 2SD13-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp D-14 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp D-3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp D-4 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp D-5 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp D-7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp E1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp S1C-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp S1C3-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp S3C4-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp S4C4-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp SB-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp SB3-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp SC-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Twin Wasp SC3-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp B | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp C | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp C1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp CD | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. B-4 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. B-5 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB-2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. SB-3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T1B3 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. T3A | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. TB | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Jr. TB-2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major B13 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major B14 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major B5 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major B6 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major B7 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major CB2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp Major TSB3-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp R-1340-59 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp R-1340-61 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1D1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1D1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1H1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1H1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1H2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S1H4 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S3D1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S3H1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S3H1-G | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp S3H2 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp SC | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp SC-1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp T1D1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp T2D1 | PRATT & WHITNEY All Models Engines |
| engine | Pratt & Whitney Division | Wasp TD1 | PRATT & WHITNEY All Models Engines |
Unsafe Condition
Cylinder flange attaching stud failures leading to engine fire due to cylinder failure, or loosening of attaching nuts causing clearance between nut and cylinder flange, resulting in severe overstress on adjacent studs.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace failed or loose studs and adjacent studs as specified. Scrap or rebarrel cylinder and replace all studs if more than two adjacent studs fail or nuts loosen. Inspect and torque nuts securely during installation, magnaflux for cracks, and lap flange if distorted within limits.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Compliance required as indicated.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Division engines: Double Wasp CA15, CA17, CA18, CA19, CA3, and other models listed in the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Cylinder Flange Attaching Stud
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_56-06-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-06-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY All Models Engines Subject: Cylinder Flange Attaching Stud Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: Double Wasp CA15 | Double Wasp CA17 | Double Wasp CA18 | Double Wasp CA19 | Double Wasp CA3 | Double...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: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 56-06-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-06-02 SUBJECT HEADING: PRATT & WHITNEY All Models Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-06-02 PRATT & WHITNEY: Applies to All Models Engines. Compliance required as indicated. As a result of engine fire reported due to cylinder failure as a result of stud failures, the following must be accomplished to reduce cylinder and stud failures: A. If a cylinder flange attaching stud fails during engine operation, the adjacent studs may be subjected to severe overstress. The same is true if an attaching nut becomes loosened to the extent that there is clearance between the nut and the cylinder flange. If more than two adjacent studs have broken, or the nuts have become loose, there is a probability that the cylinder flange has been overstressed. B. If, during line inspection or at engine teardown prior to overhaul, a nut is found to be loose or there has been failure of a stud, replace that stud and the two adjacent studs. C. If more than two adjacent studs have failed or if more than two adjacent nuts are known to have been loose during engine operation, the cylinder should be scraped or rebarreled and all the studs on the cylinder mounting pad replaced. D. If only two adjacent studs have failed or two adjacent nuts have been found loose, the cylinder should be replaced, but it need not be scrapped provided that the nuts adjacent to the failed studs or loose nuts are found to be at least to minimum torque and that the cylinder flange has not become distorted more than 0.003 inch; also, that the flange and area above the flange are magnafluxed and show no crack indicators. If the bottom of the cylinder flange is not perfectly flat, but is not distorted more than 0.003 inch, it should be lapped flat before reinstallation. Before a replacement cylinder is installed, the crankcase studs immediately adjacent to the two broken or loose ones should be replaced. E. During cylinder installation, securely tighten the cylinder flange attaching nuts. (P&W Service Bulletin No. 1000 describes approved methods and torques.) (This subject is also covered in P&W Alert Bulletin No. 42 entitled "Cylinder Attachment Inspection and Maintenance".) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_56-06-02.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-06-02 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: PRATT & WHITNEY All Models Engines Subject: Cylinder Flange Attaching Stud Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Pratt & Whitney Division Model: Double Wasp CA15 | Double Wasp CA17 | Double Wasp CA18 | Double Wasp CA19 | Double Wasp CA3 | Double...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: Updated RGL applicability to match AD applicability; CAR C-11-185 AIRWORTHINESS DIRECTIVES FINAL RULES: 56-06-02 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-06-02 SUBJECT HEADING: PRATT & WHITNEY All Models Engines ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-06-02 PRATT & WHITNEY: Applies to All Models Engines. Compliance required as indicated. As a result of engine fire reported due to cylinder failure as a result of stud failures, the following must be accomplished to reduce cylinder and stud failures: A. If a cylinder flange attaching stud fails during engine operation, the adjacent studs may be subjected to severe overstress. The same is true if an attaching nut becomes loosened to the extent that there is clearance between the nut and the cylinder flange. If more than two adjacent studs have broken, or the nuts have become loose, there is a probability that the cylinder flange has been overstressed. B. If, during line inspection or at engine teardown prior to overhaul, a nut is found to be loose or there has been failure of a stud, replace that stud and the two adjacent studs. C. If more than two adjacent studs have failed or if more than two adjacent nuts are known to have been loose during engine operation, the cylinder should be scraped or rebarreled and all the studs on the cylinder mounting pad replaced. D. If only two adjacent studs have failed or two adjacent nuts have been found loose, the cylinder should be replaced, but it need not be scrapped provided that the nuts adjacent to the failed studs or loose nuts are found to be at least to minimum torque and that the cylinder flange has not become distorted more than 0.003 inch; also, that the flange and area above the flange are magnafluxed and show no crack indicators. If the bottom of the cylinder flange is not perfectly flat, but is not distorted more than 0.003 inch, it should be lapped flat before reinstallation. Before a replacement cylinder is installed, the crankcase studs immediately adjacent to the two broken or loose ones should be replaced. E. During cylinder installation, securely tighten the cylinder flange attaching nuts. (P&W Service Bulletin No. 1000 describes approved methods and torques.) (This subject is also covered in P&W Alert Bulletin No. 42 entitled "Cylinder Attachment Inspection and Maintenance".) FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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