
Originally Posted by
Captain_Rightfoot
In passenger jets they sometimes have to be conscious of wheel speeds as there are maximums. A heavy ship on a downwind takeoff might have to consider that.
Yes, there are other factors as well, I simplified a bit. There may be tyre speed limitations as well, but downwind takeoffs where the speed is high enough to be a concern would be very rare as there are very few runways long enough for them to even be thought of by aircraft heavy enough for it to be an issue.
Not really covered in my summary is the issue of the effect of air density on engine performance and propeller efficiency. Both turbine and piston engines have reduced maximum power at lower air densities (primarily due to altitude), and in some cases the power handling capability of a propeller will be limited by the propeller tips reaching Mach 1.0 - when power is used to produce what is essentially a sonic boom, but sounds like a loud howl. Not uncommon with high powered light aircraft taking off in the PNG highlands, where density altitude can be around 10,000ft. I have heard it at Mt Hagen, Mendi and Goroka.
John
JDNSW
1986 110 County 3.9 diesel
1970 2a 109 2.25 petrol
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