These are the classic Comanches and represent a nice balance of performance, useful load, range, and simplicity. Some 2,537 Comanche 250s were sold. Most of these airplanes came with carbureted 250-hp, Lycoming O-540-AIA5 engines, but a small number were fitted out with fuel-injected versions of the same engine. Like the Comanche 180, early Comanche 250s came with hand brakes, manual flap controls, and 60-gallon fuel capacities. Toe brakes and the 90-gallon-capacity auxiliary fuel system was available in 1961. Electrically actuated flaps were made standard with the 1962 model year. A gross weight increase - from the original 2,800 pounds to 2,900 pounds -came in 1961. This had the effect of raising the 250's useful load to 1,270 pounds. Full-fuel payloads with the higher gross weight and 90-gallon fuel system run around 660 pounds.
The Comanche 250 was a great performer, with cruise speeds from 140 (55-percent power) to 157 (75-percent power) knots and fuel burns anywhere from 10 to 14 gph, respectively. Ranges with 45-minute reserves run the gamut, from about 1,250 nm (90-gallon fuel system, 55-percent power, at 15,000 feet) to 600 nm (60-gallon fuel system, 75-percent power, at 8,000 feet).
Comanche 250s (and 180s) with engines having standard-sized 7/16" valves have 1,200-hour recommended time between overhauls (TBOs). If a modification is made to install larger, half-inch valves, and most owners have done this by now, the O-540's TBO climbs to a more respectable 2,000 hours of operation.
Average-equipped prices of new Comanche 250s ranged from $21,250 (1958) to $26,900. This pricing structure made 250s only $3,000 to $5,000 more expensive than the 180s. This explains the 250's greater sales and popularity.