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This might clarify things:
Warbirds in the 21st Century
Warbirds are evolving, just like any of nature’s creatures that have survived to modern times. Up until very recently Warbird owners and restorers have felt they can freely rebuild, repair, and improve their valuable airplanes as they see fit, providing they determine the aircraft, its engines, and accessories are safe for flight. While there are a number of existing FAA rules and regulations that establish minimum standards and requirements for maintenance, modification, and operation, in many instances practice has been to allow self-regulation by owners/operators, overseen and/or inspected by FAA inspectors. Many of these inspectors had grown up with high performance recip powered airplanes, and understood these airplanes and the people, and knew what aspects were critical. A fair amount of latitude regarding rigorous compliance with the FAA rules and regulations resulted, yet in general, the aircraft have performed safely and reliably. The generation of aviation people that grew-up with high performance recip airplanes is now retiring, and the “rules”, at least their application, is changing.
A recent example of this occurred in January 2006 when Bud Wheeler of Allison Competition Engines, Latrobe, PA, had his Powerplant Mechanics Certificate suspended for 90-days. There has been a lot of miss information about this case and it needs to be set straight. Here is what happened.
In 1998 Mr. Wheeler was asked to overhaul two Allison V-1710s from a P-38. These engines had been modified in 1981 by having their original 8.1:1 supercharger gears replaced by 9.6:1 gears. The owner of the airplane asked to retain these gears and to also install pistons modified to have three modern rings in place of the original Allison five-ring arrangement. When the overhaul was complete the statement “overhauled in accordance with the Allison manuals” was placed in the logbook. In 2005 a new owner of the airplane decided to open the engines during a general restoration of the aircraft and found the non-standard parts. He reported this to the FAA, who then raised the issue to a safety of flight level and sought to revoke Mr. Wheeler’s Powerplant certificate. This action resulted in the recent NTSB trial and the judge’s finding that, “…Wheeler does not lack the qualifications to be the holder of a mechanic certificate with power plant rating.”
The basis for the 90-day suspension of certificate were Parts 43.13(a) and (b), and 43.3(a). These all are relative to having installed parts in engines from a “Limited” certificated airplane that are not identified in the original manufacturers manuals, without having obtained approval for the changes from the FAA. In the November 2005 through February 2006 period the engineering basis supporting these changes was submitted to the FAA and approvals for the following changes have been issued to Allison Competition Engines.
• 3-Ring Pistons in both standard and chrome liner engines
• Cadmium Plating of engine hardware
• Renewal of crankshaft bearing plating
• Installation of improved Distributor Shaft seals
• Installation of late model valve springs
• Installation of modern gaskets and seals
• Coolant Pump Seal Modernization
Two more changes are in the submittal process, for approval to use modern anti-friction bearings and modern spark plugs.
The classic Warbird industry argument is that the Allison engine is not a “Type Certificated” engine; therefore, practically anything the owner wants can be done to it. Not so says the FAA. “Limited” category airplanes like many of the P-38s are “certificated”, and by association, so are the engines, the accessories, and everything else about the airplane. This places all work done on the airplane under Part 43 of the regulations. It doesn’t say that modifications and changes cannot be done, but it does require that a sound engineering basis for changes be established, and that the FAA approve them. Secondarily, many Warbirds are operated in the “Experimental” category, were Part 43 does not directly apply. The caution here is that specific airplanes have “restrictions” written into their licenses, which may have the effect of requiring Part 43 compliance. In recent discussions with the FAA it appears that this is the direction they are going in the 21st century, and that the Warbird industry can anticipate greater scrutiny and configuration oversight than has generally been enforced during the past 60 years.
Allison Competition Engines, under the direction of Bud Wheeler, has a reputation for supplying the best V-1710s in the world. That he has been singled out for this level of scrutiny shows that the FAA is getting serious about compliance with the finer points in their regulations. It clearly sends the message to the Warbird industry that it is not enough to build the best airplanes possible: the paperwork has to be to a similar standard.
March 3, 2006
Bud Wheeler, President
Allison Competition Engines
PO Box 995
4686 Route 982
Latrobe, PA 15650
724-539-0241
Last edited by DaveM2 on Sun Mar 05, 2006 11:44 pm, edited 1 time in total.
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