The Chase XCG-18A and YC-122 Avitruc, created by Chase Aircraft, was an American military transport aircraft that was manufactured in limited quantities during the late 1940s.
Originally designed as a glider, it eventually transitioned into a powered aircraft.
Unlike its predecessor, the CG-14 cargo glider, the Avitruc boasted a larger size and was constructed entirely out of metal.
This high-wing cantilever monoplane had a rectangular fuselage with a loading ramp located at the rear.
The main undercarriage units were fixed and positioned on the sides of the fuselage, while the retractable nosewheel completed the landing gear configuration.
To provide propulsion, two radial engines were housed within nacelles situated in the wings.
The USAAF’s experience with cargo gliders during World War II showed that a similar aircraft would be useful in the post-war period, but one that could carry a much heavier load and be more recoverable than the wooden assault gliders used during the war.
To meet this need, Chase’s CG-14 was chosen as a starting point, and in January 1947, the USAAF ordered an enlarged, metal version of the aircraft, initially called the XCG-14B but later renamed the XCG-18A to reflect the fact that it was essentially a new aircraft.
When the prototype flew in December of that year, it was the world’s first all-metal transport glider.
One of the major improvements was the use of a thinner wing section, which allowed for high tow speeds and made it possible for smaller aircraft like the P-47 fighter to tow it into the air and to its release point.
In March 1948, the service placed an order for four additional aircraft, now designated as XG-18A, and a fifth one to be equipped with engines, known as the YC-122.
Although the air force eventually lost interest in acquiring assault gliders, they continued to develop the powered variant.
Two more examples were purchased for evaluation as the YC-122A, and the second of these was later redesignated as the YC-122B when the original Pratt & Whitney engines were replaced with Wright units.
This particular aircraft would serve as the foundation for the definitive service trial version, the YC-122C.
A total of nine of these aircraft were ordered, and they performed admirably during evaluation, first at Sewart AFB in Tennessee and later at Ardmore AFB in Oklahoma.
However, the USAF ultimately decided that there was no longer a need for a small transport aircraft and subsequently terminated the project.
Despite its relatively short existence, the aircraft saw extensive use at Ardmore AFB.
By February 1955, Captain Phillip C. Gromley of the 16th Troop Carrier Squadron, 463rd Troop Carrier Wing, had accumulated an impressive 1,000 hours of flight time piloting the aircraft.
However, by July 1955, all the YC-122C assault transports had been replaced by Fairchild C-123B Providers.
The final YC-122C was flown to Davis-Monthan AFB in Tucson, Arizona, on 30 August 1955, for storage.
Captain Gromley is credited with making the last flight of a YC-122C to Tucson.
The remaining aircraft continued to serve in utility roles until 1957. Variants Chase MS.7 Company designation for the XCG-14B / XCG-18A XCG-18A XCG-14B re-designated XG-18A revised glider version YC-122 prototype
Powered version, an XG-18A with Pratt & Whitney R-2000-11 engines YC-122A refined version of the YC-122 YC-122B YC-122A re-engineered with Wright R-1820-101 engines YC-122C definitive service trials version Specifications YC-122C Crew Two pilots Capacity 30 troops
Or
24 stretchers
Or
cargo Length 61 ft 8 in (18.80 m) Wingspan 95 ft 8 in (29.16 m) Height 24 ft 8 in (7.52 m) Wing area 812.8 sq ft (75.51 m2) Aspect ratio 11.25:1 Empty weight 19,000 lb (8,618 kg) Max take-off weight 40,000 lb (18,144 kg) Powerplant 2 × Wright R-1820-101 9-cylinder air-cooled radial piston engine, 1,425 hp (1,063 kW) each Performance Maximum speed 240 mph (390 km/h, 210 kn) Cruise speed 200 mph (320 km/h, 170 kn) Stall speed 75 mph (121 km/h, 65 kn) Range 1,000 mi (1,600 km, 870 nmi) with maximum cargo Service ceiling 29,100 ft (8,900 m) Rate of climb 1,340 ft/min (6.8 m/s)
Sources
Jane’s All The World’s Aircraft 1951–52-L Bridgman.
