56-06-02: Cylinder Flange Attaching Stud
FAA order 56-06-02 is an airworthiness directive. The FAA's subject line: Cylinder Flange Attaching Stud. It names the Pratt & Whitney Canada JT15D 5 series, Pratt & Whitney J60-P-6, Pratt & Whitney JT12A-6, Pratt & Whitney JT12A-8, Pratt & Whitney JT3D-3B, Pratt & Whitney JT3D series, Pratt & Whitney JT4A-3&5 series engines: about 473 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Engine
- Makes
- Pratt & Whitney Division
- Models
- Double Wasp CA15, Double Wasp CA17, Double Wasp CA18, Double Wasp CA19, Double Wasp CA3, Double Wasp CA5, Double Wasp CB16, Double Wasp CB17, Double Wasp CB3, Double Wasp CB4, Double Wasp R2800-97, Hornet A, Hornet A-1, Hornet A-2, Hornet A-3, Hornet B, Hornet B1, Hornet B1-G, Hornet S1B1, Hornet S1B1-G, Hornet S1E-G, Hornet S1E2-G, Hornet S1E3-G, Hornet S2B1, Hornet S2B1-G, Hornet S2E-G, Hornet S3B1, Hornet SB-1, J60-P-5B, JT12A-6, JT12A-6A, JT12A-8, JT3C-12, JT3C-4, JT3C-6, JT3C-7, JT3D-1, JT3D-1-MC6, JT3D-1-MC7, JT3D-1A, JT3D-1A-MC6, JT3D-1A-MC7, JT3D-3, JT3D-3B, JT3D-3C, JT3D-5A,...
- Engine series
- Pratt & Whitney Canada JT15D 5 series 451 aircraft
Pratt & Whitney J60-P-6 2 aircraft
Pratt & Whitney JT12A-6 2 aircraft
Pratt & Whitney JT12A-8 12 aircraft
Pratt & Whitney JT3D-3B 3 aircraft
Pratt & Whitney JT3D series 2 aircraft
Pratt & Whitney JT4A-3&5 series 1 aircraft
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (2,097 characters)
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".)
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 7, 2026. Connections as data: /graph/directive/56-06-02.json · aircraft systems.