How long does it take from starting of turbine or turbofan or turboprop, either by using an APU or other methods, until the engine is warm enough for safely extracting full power for takeoff?
A320 with IAE engines has one of the longest shafts in business, and thus is most sensitive to temperature variations/deformations.
Don’t know what the producer requires, but operator procedure is 5 minutes from start to take-off power if the engine was shut down for more than 2 hours before.
Interestlingly enough, this is on top of other temperature limitations (eg min oil temp) and is the same time, regardless of outside temperature ( eg oil on cold day may take longer to warm up)
The P&W engines like the JT-3, JT-8, JT-9 are usually above minimum T.O. temperature by the time the After Start Checklist is completed. Initially, oil pressures can be on the high side in very cold weather but will quickly come down as the oil gets warmer. I have never had a T.O. delay due to engine temperature or pressure restriction with these engines. This was definitely not the case with the large radial engines when we had to have at least 40 deg. of oil temperature before the throttles could be moved above 1000 RPM to protect the engine and this could take several minutes. The large Russian aircraft like the IL-76 also play this warm-up game. The turbine blades in these engines are made of lower quality material than that of their American counterparts. They require warming up the engines in stages which involves several increases in power corresponding to increases in temperatures until such time as take-off power can be accepted by the engine without turbine or shaft failure. The procedure usually takes 10 to 15 minutes an a cold day.