Page 26 - Volume 13 Number 11

24 • KING AIR MAGAZINE
manufactured using metal honeycomb materials. The wing, which spanned 29 feet, 10 inches with an area of 150 square feet, was mounted midway up the fuselage and featured three different airfoil sections along the span to preserve airflow across the ailerons deep into a stall. The cantilever empennage was all-metal. The tricycle landing gear was operated hydraulically and was designed to extend and lock into place if a complete hydraulic failure occurred.
Dual ejection seats were installed with the rear seat raised slightly to improve the instructor’s forward field of view. The large canopy could be jettisoned. Temco officials claimed that the engine could be exposed for inspection in only 10 seconds and a complete engine change was possible in only 20 minutes. The prototype Model 51 took to the sky March 26, 1956, and later was flown to NAS Patuxent River, Maryland, where it was evaluated alongside the Beechcraft Model 73 Jet Mentor.
According to Beech Aircraft Corporation historian William H. McDaniel, the Model 73 was proposed as a private entry based largely on the Model 45 Mentor piston-powered primary trainer that was serving with the Air Force and Navy. Billed by Beech as “the most economical jet trainer in the world,” the Jet Mentor was designed from the outset as a low-cost, economical yet high performance aircraft, and could lay claim to being the first lightweight, single-engine jet aircraft manufactured in the United States.
To minimize design and development costs, Beech Aircraft’s engineering department took a few pages from its ubiquitous airframe “cookbook” to build the Jet Mentor. Because acquisition and operating factors were such important considerations in the competition, the airframe borrowed major assemblies from the Model 45 Mentor (USAF T-34A and T-34B), such as the outboard wing sections and the empennage. The tricycle landing gear was operated electrically (same as the Model 45) and featured single-disc brakes (as did the Mentor). As with the Temco Model 51 and the Cessna Model 318, the Model 73 was propelled by the Turbomeca Marboré II turbojet engine. It was built in America by Continental under license from the French manufacturer as the military J-69-T-7, rated at 920 pounds static thrust.
Basic specifications of the Jet Mentor included: = Wingspan – 32 feet, 9 inches
= Wing area – 177.6 square feet
= Aspect ratio – 6.05
= Chord – 65.33 inches = Dihedral – 7 degrees = Single-slotted flaps
NOVEMBER 2019