PIPER CHEYENNE (400LS)

In the late 1970s, Piper avoided developing a clean-sheet light business jet to compete with the Cessna Citation I and upgraded its PT6As from 720 to 1,000 hp (540 to 750 kW) Honeywell TPE331-14s. The PA-42-1000 Cheyenne IV was certified in 1984, 44 were built until 1991 and 37 remain in service in 2018. Due to its top speed over 400 mph, it was renamed Cheyenne 400LS when Lear Siegler owned Piper then Cheyenne 400.

Flat rated to ISA+37, the turboprops maintain their power to almost 20,000 ft (6,100 m). The 106 in (2.7 m) Dowty Rotol propellers had four round-tip composite blades and 8 in (20 cm) of ground clearance. Its empennage was enlarged for stability at higher speeds and altitudes, and its fuselage was strengthened. Pressurization was increased to 7.6 psi (0.52 bar) to elevate its ceiling from 35,000 to 41,000 ft (10,700 to 12,500 m) while maintaining a 10,000 ft (3,000 m) cabin.

It can carry eight passengers farther than a King Air 200 while cruising 50 kn (93 km/h) faster. It can operate out of 3,000 ft (900 m) runways with a 97 kn (180 km/h) minimum control speed, similar to a King Air 300. It can operate from much shorter hot and high runways than a Citation I and landing is shortened by the rotating speedbrake effect of the propellers in beta pitch.

Aircraft of similar role, configuration and era are: Beech Super King Air, Cessna 441 Conquest II, Embraer EMB 121 Xingu, Mitsubishi MU-2, Piaggio P.180 Avanti.