The Genesis of the XAT-6E

The story starts with the appearance of the first production  run in 1940.  The AT-6 was manufactured by North American Aviation (NAA) and was derived from another successful North American trainer, the BT-9.  The AT-6 was licensed, by North American to other Allied countries including Australia, Sweden, Canada and England.  In the United States the AT-6 was known as the Texan and in England as the Harvard.  15,000 planes were manufactured with six versions, the last being the AT-6F.  In the early 50's, NAA acquired all of the AT-6's available and remanufactured them into T-6G's.  The Texan was powered by a Pratt and Whitney R-1340-AN-1 engine, rated at 600 hp.

During 1932 and 1933, Fairchild Aviation developed a 12-cylinder version of their six-cylinder design, known as the Ranger 6-390.  This was an inverted, air cooled, engine with two rows of cylinders in a 60 degree V configuration.  The new engine was designated the Ranger V-770.  The initial horsepower was rated at 270 hp and evolved up to 575 hp.  The major production use was the 520 hp version used in the Fairchild AT-21 twin engine trainer.  During 1944, Fairchild proposed and the Air Force agreed to re-engine the AT-6 with the Ranger engine designated the XAT-6E.  The concern was that there would be a shortage of the Pratt and Whitney engines and that most army fighters of the period were powered by inline engines (P-40, P-39, and P-51's).  Even though the XAT-6E demonstrated increased performance, the war ended and there was now a surplus of AT-6's and the Air force was in the market for a new trainer design.  Another reason given for not continuing the program was that the engine proved to be mechanically unreliable and a maintenance nightmare.

The XAT-6E, tail number 42-84241 was a standard AT-6D taken off the North American production line.  The plane survived the war and was sold as surplus.  The plane re-designated NX7410 was flown by its owner in several air races and then finally sold to someone in South America where it was converted back to the AT-6 configuration.

All the World War II Allied pilots flew the AT-6 during advanced training.  The trainer was so successful that it was still being used as late as 1955 in England and until September of 1957 in the United States.  The T-6 was used during the Korean War (1950) as an airborne tactical air controller and forward observer.  By the time of the Bay of Pigs Cuban invasion (1962) a large number of AT-6's were cut up and sold for scrap.

There were two stories given for the destruction of these aircraft, both plausible.  The first was that the U.S. government was afraid that the Cuban government would obtain the planes and arm them to use against the US and its allies. The second was the General Aviation industry's fear of a large number of inexpensive surplus planes being dumped on the market. Especially when many of their potential customers had flown the AT-6 during the war.  A number of these planes were bought by a company that provided aircraft for the movie industry.  Around the mid 80's one of these planes was donated to the Western Museum of Flight.

The Restoration Program

The restoration started, in 1985, with the re-skinning of the aft fuselage.  Soon after the completion of this task, restoration stopped until 1995 when the program was restarted.  The first task was to sand blast and repaint the center fuselage structure.  The picture on the left shows the restored fuselage structure.  When the aircraft was scraped, by the Air Force, the trailing edges of the wings were cut off as well as cutting off the rudder, elevators and gutting the aircraft.  Work started on the center wing section.  This included the rebuilding of the trailing edge, building center wing tanks and replacing corroded parts.  The tank covers were build from scratch.  New ribs were made and riveted the cover.

Once the work was completed the center wing section was primed and ready to be married to the fuselage structure and the aft section. The first step was mounting the center fuselage frame to the center wing.  The completed assembly was then united to the aft section.

The next phase of the program involved mounting the outer wings to the center wing attach angles and rebuilding the outer wing trailing edges.  Before this task could be completed the damaged attach angles had to be repaired and rib forms had to be manufactured.  T-0 Aluminum was used to form the ribs.  After forming, the ribs were sent out to be heat treated and then riveted to the structure.  New Aileron fitting were machined and installed.

The Elevators  were cut off the plane and therefore new attach fittings had to be machined.  Damaged ribs were replaced using the same procedures in rebuilding the trailing wing edges.  Forms were made and used to fabricate the ribs using T-0 material and then heat treated.  Damaged edges were repaired.  The assembly covered with Dacron, doped and primed.

By this time new engine mounts were machined and installed through the firewall to the fuselage structure.  The Ranger engine was than hoisted up into place and mounted to the fuselage.  Since the structure from the firewall forward was unique to the AT-6, all new frames and supporting structure had to be designed and fabricated.  Not only was the structure new but the Ranger engine required a new cowling.

The cowling was  made from fiberglass and  required the manufacture of a mold.  Fiberglass cloth was then laid over the mold to form the rough cowling.  This rough cowling was then sanded smooth, primed, and fitted to the front engine compartment frame.

Once the Cowling and frames were complete the next step was to manufacture the engine compartment skin panels.  Original pictures of the XAT-6E were used to determine the partitioning of the panels and the placement and number of the engine vent doors. All attach fittings had to be made.

One of the major tasks that was accomplished in parallel with the engine compartment activities was the refurbishing of the cockpit canopy.  New locking hardware was machined and installed.  Molds were made to form the curved sections of the canopy. The parts to be formed were placed in a high temperature oven and shaped in the molds.

With all the construction completed the next phase of the program was painting.  This process started with the preparation of the metal surface by etching all bare metal and sanding painted or primed surfaces.  The fabric surfaces were coated with a rejuvenating solution.  The major assemblies were then masked and primed. The final top coat was then applied.  All emblems were then masked off and painted.

All sub assemblies were then installed.  This included the elevators, ailerons, trim tabs, wheel covers and rudder.  The aircraft was now ready for roll out and the final installation of the wings.

The picture on the right shows the unique air intake of the engine compartment.

The streamlined engine compartment allowed the XAT-6E to fly higher and faster than its counter part with the traditional radial engine.

The XAT-6E on Display at the WW II Air Combat Expo held in Hawthorne, California on February 17, 2002.