Originally Posted by
Saint Jack
"Does it make a difference whether it is a turbine or reciprocal engine?" I've not worked with recip-powered helicopters so can't give a definitive comment, but I would imagine it's pretty much the same. I've seen turbine-powered helicopters sit on the ground for 20 - 30 minutes with their engines running, all in a days work on some operations.
For recip's it's not so much about cycles, but it is very much about the time factor.
Consider the garden variety R44. Even with a warm engine, you figure it's about 3 minutes from activating the starter to full rotor RPM, and on shutdown 2 minutes of cool-down (minimum, unless it's very cold out), 30 seconds of throttle closed spin down to pulling the mixture, 30 seconds before rotor brake can be applied, and call it 30 seconds getting the rotor stopped. About 3.5 minutes for shutdown total. Optimistically, one cycle is going to take about 6 minutes or a tenth of an hour. That is unsupportable for operations like rides at special events, agricultural op's, etc. Time is money! The op's around here like to see at least 6 loads an hour for rides, including loading and unloading. It's a quick trip at $30/seat. It would have to be 3 times that or more if the helicopter shut down each time, and nobody would pay it.