Some larger airliners must get ground control permission before starting their engines.

  1. Is this based on size? Does a Learjet need permission?

  2. Is this just turbines? For example does a DC3 or DC6 need permission?

  3. How would a pilot find out? Does the airport supplement or some other document show when it is required?

  4. Are there exceptions such as jets parked on remote ramps, not at gates, non-commercial?

I know from flying small recips that I never needed permission anywhere in the US or Canada - but certain airliners did.

This airport in Australia says they enforces their right for the engine start. Part of the authorization comes from environmental noise control. townsvilleairport (Australia).

Van Nuy - US, "All aircraft with engines capable of producing more than 14,750 lbs. of thrust must be pushed back or towed onto the taxiway prior to engine start." (Airport ops) (Of course you need ground approval prior to entering a taxi way...)

When working at Anchorage International, Alaska with Continental 737-757, we had to contact ground control. We could start the engines at the gate while doing maintenance; there were no ground crew around. We started the onboard APU, turned on the red strobes, got permission from ground, then started the engines. I never read a document, this info was relayed to me by my supervisors.

  • $\begingroup$ I wonder if you are confusing communication with ground control and ground crew. Ground control are the nice folk in the control tower who authorise movement on taxiways, and don't care when the engines are started. Ground crew however are airline personnel, and do care when the engines are started because they might get sucked in to one! One of them is usually communicating to the pilots during pushback via a headset connector, and sometimes in videos you might hear the pilots asking them if everyone is clear before starting the engines. $\endgroup$
    – Ben
    Commented Jan 3, 2018 at 2:20

2 Answers 2


Airliners usually push back from the gate and then start their engines when well clear.

If the aircraft has an unserviceable APU, a ground based power supply must be used at the gate for the start. Permission(coordination) is required so that their are no hazards for ground crew and vehicles in the gate area.

After one engine is started at the gate, the aircraft is pushed back. The next start, still needs permission(coordination) because the operating engine usually has to increase it's thrust above idle in order to have enough bleed air pressure for the "Cross Bleed Start".

EDIT: "Permission" may be not be mandatory at many airports, so "Coordination" with Apron Control, Ramp Control, or Ground Control may be a better description.

  • $\begingroup$ Is the tower responsible for making sure personnel are clear? That seems like something you would coordinate with the crew chief $\endgroup$
    – TomMcW
    Commented Jan 2, 2018 at 17:55
  • 2
    $\begingroup$ The ramp crew doesn’t know which aircraft are going to be taxing behind the aircraft $\endgroup$ Commented Jan 2, 2018 at 19:23
  • $\begingroup$ Is engine start generally assumed to be part of pushback clearance? $\endgroup$
    – TomMcW
    Commented Jan 2, 2018 at 19:24
  • 1
    $\begingroup$ I'm not sure that "permission" is the correct term. I think its a function of most airliner crews can't see behind them so someone with a good vantage point can assist in making sure they are clear, but I'm not familiar with any regulation that requires "permission" from ATC to start engine on ramp. If there is such a regulation it would be very enlightening to see it. I used to work on ground crew for 747, 767, 757, and another others at UPS and our ground crews handled clearing pilots to start the engines (i.e. making sure all were clear). Of course we did have our own private ramp area. $\endgroup$
    – Devil07
    Commented Jan 2, 2018 at 22:52

Two separate things:

  • you get a “clear” for engine start from the ground crews (either handsignals or via heatset/intercom) to ensure the area ahead/behind the engines is clear. Mind you, most cockpits you cannot see the engines, let alone the area behind them.

  • you get a “clear” for engine start from ATC via radio, though (much like the taxi instructions) this is not a clearance per se. It is more an ‘agreement/acknowledgement’ with ATC that you will be moving soon enough (they know it slightly better when you will be taxing) so you might go ahead and start the engines. They might need to keep you from moving another 10-15 minutes (departure slot, other trafic taxiing by,etc) at which point I’d preffer to wait with engines stopped.

It gets a little bit more complex if there is a pushback involved, especially at airports where ‘start’ is cleared on DLV frq and ‘pushback’ is cleared on GND frq, but most of the times the two clearances mean the same thing: the airport is ready to handle your traffic.


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