In 1948, senior management at Beech Aircraft Corporation saw the need for a new military trainer to equip postwar air forces. Their solution was the “Mentor” that would become one of the most popular Beechcrafts ever built.
When World War II ended with the unconditional surrender of Japan in September 1945, the United States Army Air Forces and the U.S. Navy continued to train cadets in the Boeing-Stearman PT-13 and N2S biplanes, respectively, before progressing to advanced trainers such as the North American AT-6 “Texan” and SNJ monoplanes. Although the AT-6 and SNJ were well suited to the task, their thirsty, static, air-cooled radial engines gulped fuel and their airframes were aging fast. In 1948, Walter H. Beech and his engineers realized there was an opportunity to replace the venerable AT-6/SNJ with a modern and cost-effective airplane that could do the work of both a primary and basic trainer.
A series of design studies commenced that year. Fortunately, a significant amount of time and development costs were reduced by using the Model 35 Bonanza airframe as a foundation for the new Beechcraft. The Model 35’s airframe and Continental engine had established a record of dependability since the airplane’s certification in 1947.
Although there is evidence that the design studies did include incorporating a V-tail on the Model 45, it was rejected in favor of a conventional vertical stabilizer that was more suitable for a military trainer. Overall, the Model 45’s dimensions were similar to those of the Bonanza, but the Mentor featured a narrow fuselage and tandem seating for an instructor and student pilot. In addition, a Plexiglas, three-piece sliding canopy covered the cockpit and provided both occupants excellent visibility.
A prototype was completed in late 1948, powered by a Continental E-185 six-cylinder, opposed piston engine rated at 185 horsepower at takeoff and 165 horsepower for cruise. The airframe was designed to withstand 10 positive and 4.5 negative g-force – more than adequate for instructing pilots in aerobatics and combat maneuvering. Veteran Beechcraft chief test pilot Vern L. Carstens took the prototype aloft for its maiden flight December 2, 1948. Maximum speed was 176 mph at an altitude of 10,000 feet, with a cruise speed of 160 mph at a gross weight of 2,650 pounds.1
Development continued through 1949 and a Model 45 was sent on a nationwide tour of military bases in the United States and Canada to demonstrate the Mentor to officials of the U.S. Air Force and the Royal Canadian Air Force. Later, the airplane was shipped across the Atlantic Ocean where Beech demonstration pilots flew more demonstrations to showcase the Model 45’s capabilities to military forces in Western Europe. One of the more interesting demonstrations, however, occurred in 1949 during the National Air Fair held at Chicago’s O’Hare International Airport.
On July 4, a Model 45 was flown by two-time women’s aerobatic champion Miss Betty Skelton before thousands of spectators. Beech Aircraft Corporation historian William H. McDaniel described it this way: “Proving that brute strength was not required to put the Mentor through a breathtaking array of maneuvers standard in military combat operations, pretty, petite, 100-pound Betty Skelton – only 22 years old and a two-time women’s aerobatic champion – thrilled the cheering crowds. To sober-minded military observers, they were a reminder of the need for continued readiness to maintain air power in the defense of the free world – a reminder already accented by the Communist blockade of Berlin.”2
Walter Beech believed in the value of public aerial demonstrations, but he was seeking orders from the military, and by the end of 1949 he had received none. In the wake of major budget cuts to America’s armed forces after World War II, money was scarce and both the U.S. Air Force and Navy were looking for airplanes that would give them “the most bang for the buck.” In March 1950, the Air Force placed an order for three YT-34 Mentors for in-depth evaluation as a primary/basic pilot training airplane. Their projected economy of operation, which was predicted to be significantly less than existing aircraft employed in that role, was a major factor in the decision to test the new Beechcraft.
According to company records, the three airplanes were designated Model A45T by the factory and YT-34BH by the Air Force. As part of the evaluation, two of the three airplanes were powered by Continental E-185-8 engines rated at 185 horsepower, while the third airplane was equipped with a Continental E-225-8 powerplant that produced 225 horsepower for takeoff. All three Mentors were tested thoroughly not only by experienced pilots, but also by pilot instructors and their students as part of the daily training routine. During the testing period, the trio of YT-34BH accumulated more than 400 hours of flight time in only 32 days. That feat was followed by a function and reliability check that lasted nearly 24 hours and involved seven landings with rapid turnarounds to refuel and change pilots. These flights were conducted at the remote site of Edwards Air Force Base, California.3
One other feat that was unintentional but did much to convince Air Force officials of the Beechcraft’s “battleship” construction, it was reported that during one of the evaluation flights a pilot accidently struck a cable while flying at more than 180 mph. The cable, stretched across the wide span of a canyon, did not break but nearly stopped the Mentor’s forward motion before spinning it around. With less than 400 feet of altitude to work with, the pilot managed to regain airspeed and control before striking the ground, and flew back to the base. Upon inspection, only the right-wing surfaces and leading edge suffered damage and bore the imprint of the cable.
Satisfied with every aspect of the rough-and-ready Model 45, in 1953 the Air Force ordered a small number of Mentors designated T-34A (company designation A45). The first two Mentors were delivered in September of that year, followed by another 88 trainers one year later. All of these airplanes were powered by the Continental O-470-13 engine rated at 225 horsepower. Performance included a maximum speed of 189 mph and a cruise speed of 175 mph at a gross weight of 2,950 pounds. Service ceiling was 20,000 feet. When production ended in October 1956, the factory had delivered 353 airplanes.4
The Royal Canadian Air Force (RCAF) also wanted the T-34A, and in 1954 the Canadian Car & Foundry Company, Ltd, of Fort William, Ontario, obtained a license from Beech Aircraft Corporation to build the Mentor. The Canadian company built 25 airplanes for the RCAF and eventually another 100 for the U.S. Air Force, bringing total production of the T-34A to 453 airplanes.
Meanwhile, the U.S. Navy had been giving serious consideration to modernizing its aging fleet of primary trainers. The Navy Bureau of Aeronautics conducted a series of very tough evaluations at Naval Air Station Pensacola, Florida. Beech Aircraft provided the Navy with one of the earliest Mentors built, but it easily held its own against competing aircraft. Despite its age, the airplane was praised by Navy pilots for its rugged construction and particularly its nearly indestructible landing gear. During testing that lasted from September until December 1953, the airplane was subjected to abuse at the hands of pilots learning how to land on the deck of an aircraft carrier. Unlike the Air Force that had long runways to land on gently, the Navy taught its aviators to slam the airplane down on the deck to catch the arresting cable and “trap” the airplane. Although the landings “washed out” the gear of some competing aircraft, the Mentor’s tricycle landing gear never failed under those severe conditions.
During the summer of 1954, the Navy announced that the Model 45 (company designation D45) had won the competition and would become the Naval Air Training Command’s primary trainer. Initial deliveries began in December. There were only a few distinctions between production Mentors for the Air Force and Mentors for the Navy. These included:
- A small, triangular fillet at the bottom of the rudder was deleted
- Provision was made for differential braking that allowed nose wheel steering for maneuvering on the ground (the T-43A featured a steerable nose wheel using the rudder pedals, much like that of the commercial Model 35).
- Rudder pedals were adjustable instead of adjusting the seat
- Wing dihedral was increased slightly
- The overall exterior paint scheme used a highly visible, bright yellow color that Navy officials believed would make the airplanes more visible in the air and around the training airfields.
Production of the T-34B began in October 1954 and continued unabated until October 1957, when the last 12 airplanes were delivered. During those three years, a total of 423 Mentors rolled off the assembly lines. Performance was almost identical to that of the T34A, with a maximum speed of 188 mph at a gross weight of 2,985 pounds (empty weight was 2,170 pounds). Maximum diving airspeed was 280 mph. All T-34B were powered by six-cylinder, air-cooled, opposed Continental O-470-13 engines that developed 225 horsepower for takeoff, and were fitted with Beech-built two-blade, constant-speed propellers that helped the Mentor achieve a respectable rate of climb at sea level of 1,280 feet per minute. During a 10-year period spanning 1948-1958, Beechcraft employees eventually built 1,904 examples of the Model 45.5
Much to the Navy’s delight, the T-34B’s record as a primary trainer allowed the service to reduce the number of flying hours to 36 from 74 because students learned more quickly in the Beechcraft than in the SNJ with its conventional landing gear configuration. The Mentor also slashed the time required to solo by more than 50%, and the overall accident rate decreased as well compared with the SNJ. In short, the T-34B taught fledgling naval aviators better and more quickly while drastically reducing operating costs.
It is interesting to note that in 1961 the Navy reported that since flight operations began in 1956 at Pensacola, more than 9,000 naval aviators had been trained in the T-34B. These airplanes had flown more than 445,000 hours and boasted a safety record five times better than their predecessors. Navy training squadron VT-1, operating from Saufley Field in Pensacola, reported a record 75,000 consecutive accident-free flying hours surpassed only by VT-3’s 80,000-hour record.
One T-34B, the 39th to roll off the Wichita assembly line, earned a “gold seal of approval” from Naval Air Training Command after completing more than 5,000 hours and traveling 700,000 miles in the air. More than 100 Navy and Marine Corps pilots had been trained in the aircraft, which records showed had made 16,459 landings, 4,604 loops, 3,401 spins and 17,904 stalls and was refueled 3,325 times.6
During the early 1960s, the U.S. Air Force began phasing out its fleet of T-34A trainers in favor of jet-powered basic training aircraft. A competition was won by Cessna Aircraft Company’s twin-jet T-37 that featured side-by-side seating for the instructor pilot and the student. In the mid-1950s, Beech Aircraft Corporation did build its own version of a jet trainer designated as the Model 73. It was powered by a single turbojet engine and its airframe borrowed heavily from the Model 45. Although the airplane flew well and made many demonstration flights, it failed to win any orders from military forces.
As for the Navy’s fleet of Mentors, they soldiered on faithfully for more than 35 years until 1975 when deliveries began of the much improved T34C. In 1973, the Navy awarded Beech Aircraft a contract to develop a turboprop version of the T-34B, and the first of two YT-34C prototypes flew in 1974. Beech engineers modified the T-34B airframe to accept a Pratt & Whitney Canada PT6A-25 turboprop engine rated at 400 shaft horsepower. The engine and other systems upgrades would extend the life of the venerable Mentor for another 25 years until being replaced by the Beechcraft T-6A “Texan II” – another PT6A-powered airplane that is currently serving both the U.S. Air Force and Navy as a basic trainer. The Navy accepted 18 T-34C trainers in 1975, to be followed during the next seven years by more than 330 airplanes. A final batch of 19 trainers were delivered in 1989.
The T34C had a maximum speed of 246 mph and possessed a service ceiling of more than 30,000 feet. It featured a wingspan of 33 feet,4 inches and a fuselage length of 28 feet 8.5 inches. In addition to the U.S. Air Force and Navy, the U.S. Army took delivery of six T-34C trainers in 1987 from Navy inventory. Three aircraft replaced the aging North American T-28 “Trojan” with their static, air-cooled radial engines that had been flown by the Army Aviation Engineering Flight Activity based at Edwards AFB, California. Another three were operated by the Army Airborne Special Operations Test Board located at Fort Bragg, North Carolina.7
The factory also built an export version of the T-34C known as the T-34C-1, powered by a 550-shp PT6A engine. It was intended primarily as a basic trainer but could be equipped to operate as a light attack aircraft. The chief modification centered on four hard points under the wings that could accommodate up to 1,200 pounds of ordinance. In the late 1970s, the Ecuadorian Air Force took delivery of 14 airplanes and Peru, Morocco, Argentina and Indonesia also ordered the T-34C-1.
Commercial and export versions of the Mentor received the company designation Model B45. Per factory records, 85 were delivered in 1953-1954, 47 in 1954-1955 and 21 in 1955-1956. Another 45 were delivered in 1956-1957 followed by 29 in 1957-1958 and 91 in 1958-1959 when production was terminated. In 1953, Chile ordered more than $1 million-worth of T-34A trainers after the Beechcraft proved superior to American, British and French competitors. Chile eventually operated a fleet of 65 Mentors. Japan soon followed by obtaining a license for Fuji Heavy Industries to build the T-34A and 137 aircraft were completed. Other armed forces that flew the T-34A include the Mexican Navy and the Venezuelan Air Force. The first sale of Mentors for civilian use occurred in 1958 when the International Training center for Civil Aviation in Mexico bought four airplanes to train pilots.
The exact number of Beechcraft Mentors being flown by civilian pilots worldwide is unknown, but a reasonable estimate is 100-150. The airplane is prized by sport pilots for its robust airframe and aerobatic capabilities, and some airplanes have been painted in U.S. Air Force and Navy color schemes that replicate the Mentor in service as a “warbird.”
Notes:
. Phillips, Edward H.: “Pursuit of Perfection: A History of Beechcraft Airplanes;” Flying Books, Eagan, Minnesota, 1992.
. McDaniel, Willian H: “The History of Beech;” McCormick-Armstrong Co., Inc. Wichita, Kansas, 1971.
. Ibid
. Ibid
. Ibid
. Ibid
. Harding, Stephen; “U.S. Army Aircraft Since 1947”: Specialty Press, Stillwater, Minnesota. 1990.