The Piper PA-30 and PA-39 Twin Comanche are a twin-engine development of the PA-24 Comanche single-engine aircraft. The Twin Comanche was developed from the single engine Comanche by Ed Swearingen who at the time operated a facility that specialized in the modification of production aircraft. No engine options were available from Piper, which produced the aircraft with two 160 hp (120 kW) Lycoming engines, but 180 hp (135 kW) and 200 hp (150 kW) engines were available as a Miller modification. A version with turbocharged engines for higher altitude flight was also developed, and the PA-39 was a version with counter-rotating engines (to eliminate the critical engine) that replaced the PA-30 in the early 1970s. As the Twin Comanche was produced on the same production line as its single-engine cousin, production ceased when the production line was wiped out in a flood in the early 1970s, and Piper chose instead to focus on its equally popular Cherokee 140/180/235/Arrow line, eventually giving birth to the highly popular twin-engine Seneca, which is essentially a Twin Cherokee Six. The Piper PA-40 Arapaho had been scheduled to replace the PA-39 in the 1973-4 timeframe. Three were manufactured, and the aircraft was already fully certified when the decision was made not to proceed with the manufacturing. One of the three Arapahos was destroyed in a flat spin accident in 1973; the test pilot (who was none other than future aviation entrepreneur Clay Lacy) successfully escaped. One was scrapped by Piper and the other one remains flightworthy as of this writing but is not currently being flown.

The Twin Comanche is the most fuel efficient aircraft in its class. With tip tanks, the aircraft holds 120 gallons (454 l) of fuel. Fuel burn at typical cruise settings is approximately 15.5 gph (58.7 lph) with a cruise speed of 165 kts. It easily climbs to 18,000' (5,500 m) when desired (24,000' - 7,300 m - if turbocharged). When compared with the Seminole (in reality a Twin Arrow), the Twin Comanche goes faster, carries more, burns less fuel, climbs more rapidly and ultimately higher, is quieter, and is more difficult for a novice to land. When compared to the Seneca, which is really quite a different aircraft, the more noticeable differences are in handling. The Seneca is like an SUV and the Comanche is like a sports car.

Three versions of the PA30 were produced: the original, a B model, and a C model. The B and C models both carry six people and can be identified by the additional side windows. Since there was no accompanying power increase, the B/C models simply give owners a fuel/passenger tradeoff issue. The back two seats are quite small. Exterior dimensions are identical among all model PA30/PA39 aircraft.

The original Twin Comanche was beset by training accidents which were subsequently improved by modifying training techniques and raising the minimum airspeed at which engine-out flights were conducted. The Twin Comanche is considered to be an unforgiving airplane to fly with only one engine but not dangerous if the pilot is properly trained and current in engine-out procedures.

The main competitive aircraft to the Twin Comanche are the Raytheon (Beech) Travelair and the Grumman Cougar. The former has higher powered engines of 180 horsepower. The latter has O-320D1D engines (same hp as the Twin Comanche but not fuel injected). Only 115 Cougars were built (versus 2000 Twin Comanches) so parts availability can be shaky. The Cougar has the advantage of being newer (1978-1979). Neither has the performance of the Twin Comanche.