Departure times

[xfeed]

With a scheduled departure time of 12.00, for example, is that the time that the plane pushes back from the gate or when it should be starting its take-off roll?

I have read that in the States if a plane pushes back at the scheduled departure time it is considered "on time". That would seem to indicate the departure time is anywhere between pushback and take-off roll but I would appreciate anyone's help in clearing this up for me. Conversely, what is considered the scheduled arrival time...the touch down onto the runway or the gate arrival? I'm guessing the landing time since many of you probably sit for a bit waiting for a gate to open.

Cheers!

[B737NG]

Departure time is push back time. The calculation for estimate time required for taxi out, take off, cruise, desent and approach as well as landing and taxi to the gate that is the arrival time. The time table gives you a departure time and a arrival time what includes all the above named phases of the operation. If you have a usually congested ramp/taxiway then there is a longer time in the time table considert as the actual average flight times
for that particular route.

NG

[xfeed]

NG,

Thanks for clearing that up for me. I appreciate the information.

Cheers!

[Old Smokey]

As a post-script to B737NG's correct statement, a departure is still considered as "on time" by most airlines if no later than 3 minutes from schedule. 4 minutes late, and you're late.

[MkVIII]

Agreed. Departure time is the time when the brakes are released, and pushback begins.

Or in the case of smaller aircraft, including turboprops, it's the time that brakes are released with all engines running.

[Firestorm]

At some airlines, I believe, it is the time that the dispatcher hands over the load sheet, and the time that the Captain rights on it, as that is the time at which the aircraft is considered to be ready to go, barring any ATC resritiction. Personally, I write down the time that we are given permission to push, after that it is a matter of fate, if you like. I don't think we have it defined in our Ops Manual.

[xfeed]

Thanks, everyone, for the information. I appreciate the responses.

Cheers!

[The SSK]

I have, in a previous career incarnation, organised a survey of numerous airlines asking them about their operating definitions, in order to arrive at industry 'guidelines' rather than standards.

Basically, it's up to the individual airline - there is no standard definition, but among the major airlines at least it is almost inevitably the start of pushback. I have however known some carriers to use 'aircraft moving under its own power' and 'doors closed'.

Equally, each airline has its own definition of 'on-time'. The commonest standard is two minutes, but I have known zero, three, four, five, ten and fifteen (the latter was a purely longhaul airline).

If you want a really grey area, ask an airline what is meant by 'scheduled' in 'scheduled time of departure'.