Main Question or Discussion Point
why propeller airplanes have superior take-off performance than jet airplanes?
Who told you they do? Takeoff performance is a function of thrust to weight ratio. At low advance ratios, propellers perform worse than they would at cruise. Some props are specifically designed as "climb" propellers, but then have lower cruise speeds.why propeller airplanes have superior take-off performance than jet airplanes?
I'm not sure what the thrust of a jet engine looks like as a function of speed, but he may well be correct.okay! this guy at the other forum makes this point which is quite confusing to me.
here's is what he says
" All aircraft's Climb Rate depends upon excess Power available. For the jet, Power, and excess Power increase as the aircraft fly at higher speeds, with excess Power reducing at very high speed as Drag builds up, and the Power Required increases. That's why jet aircraft Climb at very high speed, typically at, and sometimes above, normal cruising speed. For the same reason in REVERSE, best Climb speed for a piston aircraft is somewhat below cruising speed.
All of this also explains why 'prop' aircraft generally have superior Takeoff performance (High low speed Thrust) with modest cruise performance, whilst their jet cousins experience have inferior Takeoff performance, but superior cruise performance "
is he correct?
We have small airports around here with short runways. Having had clients fly in with both small jets and turbo-props (and conventional prop-planes) I can assure you that the folks with the private jets needed a lot of room to get off the ground, while the folks with the turboprops jumped off the runways quite promptly. I always assumed that being able to change the prop pitch allowed the turbo-props to "claw" their way through the air and gain altitude quickly. Could be wrong about that, but turbo-props seemed to be pretty muscular at take-off.and suppose if : Two identical aircraft of equal weight, one powered by turbojet, the other by turboprop, are lined up on parallel runways. Both will fly their maximum rate of climb performance. how do we compare their AOA and TAS?
my answer to this is ' AOA for the prop is higher & TAS for the jet is higher'.
m i correct?