Cleared for take off?
 

Greetings fellow aviators! :-)

I have a Q! A rather stupid and easy one perhaps, but I have been thinking about it lately.

At what point is the aircraft cleared for take off, and it is okey to press TO/GA? Is it:
1: When ATC starts to say you are cleared for take off
2: At the point where ATC says the words "cleared for take off"
3: At the point when PM reads back the clearance

In order to achieve MROT, when are you guys setting take off thrust?

There's no rule on this--use some long-lost common sense. Your looking down the runway, it's clear, checklist is complete and PM is ready to go, you get the clearance, push up the throttles and go. I'd wait until ATC has the learance out, so as not to jump the gun.

Has aviation training now reached the point we need a rule for English fluency? How did you depart without ATC giving you a clearance?

Let me look at the second part of your question, which is when it is ok to press TOGA.

Is it 1, when ATC just starts to pronounce your call sign? This might as well become a request to vacate the runway again or an information about an increased tailwind component, birds on the runway or anything else the controller wants you to know so you can decide whether you are at all inclined to accept a takeoff clearance. Logically, this cannot be right.

Is it 2, when you hear the magic words? May well be; from his side you are authorised to depart his runway. But a clearance for takeoff is not to be confused with an obligation to take off; you can of course reject it. A technical issue might be a reason, as is the question if you have understood his clearance correctly. Now this is not so much an issue in the corner of the world you are used to operating in, but there surely are areas in which ATC is less well understandable, tends to use nonstandard phraseology or even uses a language to communicate with you that it does not use on most other aircraft in the sector. Would you like to confirm that every crew member in the flight deck has understood the same words you believe to have heard? If so, make sure it is so; then this answer cannot be right though. If not, well, go.

Or is it 3., when the PM has read back the clearance? You have heard the clearance, PM has repeated it to the controller, who in turn chose not to call you back to correct what he just heard. So everyone is satisfied that you are good and approved to go.

From a logical and also from a CRM standpoint, it must be thus.

Adding to Tu's No. 3, we still have to do a few extra things AFTER we have been cleared (confirm, lights on, spool up to 40%). Only when the engines are accelerating together at 40% do we selected TO power.

Can't comment on the flight deck procedures, but, technically, an aircraft is cleared for take-off when ATC have issued the clearance, the crew have read it back, and ATC have not corrected any part of the readback. For a professional pilot to have any doubts about this would be worrying.

In practise I've never had any problems with engines increasing power as the clearance is read back, but one needs to be aware of predictive or confirmation bias creeping in to such situations.