Aero Spacelines Mini Guppy

The cargo area of the Mini Guppy

The Mini Guppy, or "MG", was built with a swing-tail to facilitate cargo loading. It was powered by the original Pratt & Whitney R-4360 Wasp Major piston engines, enabling it to carry a maximum load of 32,000 pounds (14,500 kg), and cruise at 250 mph (400 km/h). Its cargo bay was 18 ft (5.5 m) in diameter, and a maximum of 91 ft 6 in (27.9 m) long, with a 73 ft 2 in (22.3 m) constant section.

The Mini Guppy first flew on May 24, 1967, and Aero Spacelines operated it for several years, ferrying contract cargo, including NASA's famed Pioneer 10 space probe and the Goodyear Europa until it was sold to American Jet Industries in 1974. American Jet Industries sold it to Aero Union in 1980, who sold it to Erickson Air Crane eight years later. Erickson Air Crane used the Mini Guppy to haul heavy equipment until 1995, when it was retired to the Tillamook Air Museum in Tillamook, Oregon, where it resides today.

The second version was officially known as the Mini Guppy Turbine (MGT) and Guppy 101. It was the first Guppy aircraft to feature upgraded Allison 501-D22C turboprop engines. Like the MG, the MGT had a 73 ft 2 in (22.3 m) constant diameter section of the cargo hold, but the overall length had been increased to 103 ft 2 in (31.4 m), and the diameter was slightly wider: 18 ft 4 in (5.6 m). This, combined with the upgraded engines, enabled it to carry a maximum payload of 62,925 pounds (28,540 kg), almost twice the load the MG could handle. It was built with a swing-nose for easier cargo loading.

Aero Spacelines Mini Guppy transporting a salvaged Dassault Falcon 20C.

The MGT first took to the air on March 13, 1970, but was short-lived. On May 12, 1970, the Mini Guppy Turbine was lost, along with the entire crew, in an accident during flight testing at Edwards Air Force Base, California.