In 1968 the company moved to better facilities in Moultrie, Georgia, and began development of an improved M-5 based on the M-4 Strata Rocket. It differed in having a 30% increase in flap area and enlarged tail surfaces to give improved. STOL performance. Two prototypes, flown in 1971, kicked off the Lunar Rocket Line. These were the M-5-210C (marketed as the Strata Rocket) and the Franklin-powered M-5-220C with engines of 210 and 220hp respectively and both entered production early in 1974. Later versions comprised the four-door unnamed M-5-180C powered by a 180hp O-360-C1F, the turbocharged M-5-210TC and the M-5-235C with an Avco Lycoming O-540-J1A5D. This was developed into the M-6-235 Super Rocket with wing span increased 0.71m, larger flaps, higher gross weight and carrying more fuel. The Maule Patroller was a derivative of the latter. Maule Aircraft went into Chapter 11 bankruptcy in 1984 and a new company, Maule Air Inc.; was formed to continue production of a new variant, the M-7. The M-7-235 Super Rocket has a bigger cabin with extra windows, plus other refinements, and a tricycle undercarriage version (the MX-7-180 Star Rocket) and a turboprop version (the MX-7-250 Starcraft with an Allison 250 powerplant) are currently under development. The MX-7-180 four-seat Star Rocket is a M-7 with short wings as fitted to the M-5, and the MX-7-235 Star Rocket has a 235hp fuel injection engine. By 1991 production of the Maule family of designs had reached around 1,700 aircraft, including the best selling M-5-235C with sales of 380.