Save the Mentor!

T-34 owners are the latest to prove the value of good old-fashioned American ingenuity.

Air & Space Magazine

he mock dogfight, on April 19, 1999, began with the airplanes outside each other's visual range. When the pilots caught sight of each other- both flying Beech T-34 Mentors in gray and blue U.S. Air Force camouflage paint, with "SW" in big black letters on their tails-the one at "perch" (the higher altitude) began a descending turn to intercept the aircraft below it.

In the rear seat of the attacking airplane was Dan Bouck, 51, of Atlanta, an airline pilot with 15,500 hours of flight time. Bouck, the safety pilot, had been flying for the Sky Warriors civilian aerial combat school for two years and had logged 450 hours in the T-34. In the front seat was the customer, another professional pilot, Ted McFann Sr., 60, who had retired from the airlines with some 25,000 hours.

T-34 Aerobatics (Leslie Hicks)
Bouck urged McFann not to be shy as he closed on the other airplane. "Roll all the way through-harder, harder! All the way through! That's it, that's right. Bury your nose, bring it down. That's it, good! Now don't chase him into the ground."

Without warning, as the T-34 made a tight left turn, its right wing separated near the fuselage. The aircraft whirled out of control. Both pilots were wearing parachutes, but as the wing failed it swung over and crushed the canopy. Both men died in the crash, which also destroyed a half-century of confidence in the structural integrity of the T-34.

The T-34 Mentor is a military trainer version of Beech's tremendously successful Bonanza, the V-tail four-seat airplane that came onto the market in 1947. For the trainer, Beech replaced the Bonanza's cabin and upper fuselage with a greenhouse-style canopy, similar to that on the World War II North American T-6 Texan trainer. Tandem seating put the student in front, instructor behind. The original engine was a six-cylinder, 225-horsepower Continental O-470. A conventional three-surface empennage replaced the Bonanza's trademark V tail, which had been intended to produce less drag but never quite provided solid yaw stability.

Bonanza (Jim Koepnick/EAA)
The Bonanza had originally been certified in the "utility" category, with a load limit of 4.4 Gs. Airplanes used for aerobatics-and those used by military pilots-must be sturdier. Their structures must be able to withstand plus 6 and minus 3 Gs without permanent deformation. They must withstand 9 Gs or minus 4.5 Gs without breaking, though the structure may be permanently bent. These are the limits the Mentor was certified to withstand. (With minor reinforcments, the Bonanza also proved capable of handling the higher aerobatic loads.)

The U.S. Air Force bought 348 T-34As, with deliveries beginning in 1953. A year later the Navy ordered a slightly modified version, the T-34B; Beech eventually delivered 423. A few foreign air forces also bought the airplane, and some were assembled under license in Japan, Canada, and Argentina. Production of the piston-engine versions ended in 1959, but Beech delivered 441 copies of a turbine version, the T-34C (or "Charlie"), to the Navy between 1976 and 1990. The 300-mph Charlie, powered by a 400-horsepower Pratt & Whitney turboprop, is 1,000 pounds heavier than the A and B models, and uses a stronger main wing spar, adapted from Beech's twin-engine Duke.

Mentors began to filter into the civil registry during the 1970s as the Air Force and Navy released airplanes to the Civil Air Patrol, foreign air forces started to retire them, and enterprising shops began assembling airplanes out of scrapped parts. (Charlies have not yet trickled down into civil hands, though many T-34 aficionados would sacrifice minor body parts or close relatives to get one.) Owners often paint them in military camouflage or in fanciful schemes mingling inspirations from several military liveries. Many T-34s have received newer, more powerful engines of 260 or 285 hp.

T-34 Wing (Harry Whitver)
Eventually, the civil fleet grew to nearly 500. Owners banded together in a T-34 Association, which organizes fly-ins and formation flights and publishes a quarterly magazine. A six-plane T-34 acrobatic team, Lima Lima, maintains a year-round schedule of performances, as does T-34 airshow performer Julie Clark.

Inflight structural failures are rare events. Usually they occur when a pilot loses control in clouds, emerges in a spin, and, in a desperate effort to recover, overstresses the airplane. Occasionally, an airplane is torn apart by turbulence in a thunderstorm. But the Sky Warriors accident was obviously in a different category.

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