Why are propeller motors unusual in commercial aircraft

Why do commercial aircraft not have turboprop engines instead of jet engines? [Duplicate]

Turboprop engines are also used in ATR aircraft. The main reasons airlines don't use turboprop engines are:

  1. They are not as efficient as jet engines for long-haul flights at high altitudes. For this reason, all turboprop aircraft are used for short-haul flights.
  2. Their efficiency decreases as the speed increases above Mach 0.6 ~ 0.7. In comparison, the Boeing 747-8 runs at around Mach 0.85. (Their efficient (cruising) speed is lower compared to jet planes (~ 700-750 km / h vs ~ 880-840 kmph). This significantly increases the travel time of long-haul flights.
  3. The cabin (and the outside) is significantly quieter in turbofan engines compared to turboprop engines. This is an important problem in civil aircraft where the noise (and vibration) affects passenger comfort.
  4. The turbofan engines, for a given size, produce much more thrust than turboprop engines (however, turboprop engine power is measured in shaft power). This makes them unsuitable for large aircraft.
  5. The huge propellers in the large turboprop aircraft require long landing gears, which add weight and make maintenance difficult.

The largest (and fastest) civilian turboprop aircraft flew slower and lower than jet planes of comparable time. It wasn't known for its comfort either.

Peter Kämpf

Points 1 and 4 are completely wrong.

cpast

@Peter Is point 1 also wrong about point 2 (which seems to say that a turboprop takes longer to fly a certain distance at efficient speeds)?

Peter Kämpf

@cpast: It depends on how you define the efficiency (see the answer on Concorde motor efficiency). However, if we take the fuel per seat mile (excluding speed), the turboprop is clearly ahead. If we use the transport service (lowest cost of seat miles per hour) the competition is tighter, but still in favor of turboprop