Originally Posted by
Intruder
Not true in general. Pushback and start clearances are required at many US airports. For example, at LAX I've received clearance for pushback, but hold start until some other aircraft cleared...
A specific engine start clearance must be received before the engines may be started at all of the major airports to which I fly outside the US. Startup clearance, per se, is not required at US airports. It is permissible to start the engines and run them at idle power without receiving an ATC clearance. Mechanics do it all the time. To move the aircraft may or may not require ATC permission, depending on the area. Some apron areas are uncontrolled, or are unofficially controlled by non-ATC entities. At ORD, the 6th busiest airport in the world, the cargo ramp from which I operate is uncontrolled -- strictly self-announce like UNICOM at a little airport. It was formerly controlled by UPS, but they no longer do so. I don't know why they stopped -- maybe a liability concern. We push back and start engines there without any clearance from anyone (of course, we have our ATC route clearance). Without any clearances from anyone, we taxi to and hold short of the taxiway and contact ground control. If an airport has gate hold procedures in effect, then we must obtain permission beforehand, even in an uncontrolled area. My domicile is LAX. We must request pushback clearance there from ground control because we are pushing back onto a taxiway controlled by them. We do not request clearance to start engines because it is not required. Of course, if ATC were to request that we not start engines due to a light aircraft taxiing behind, we would comply. But at most (all?) big airports outside the USA, you must request an engine start clearance along with a pushback clearance. You will get cleared for both at the same time or you will get cleared for one, and later, the other.