Expert: David A. NewMyer - 4/17/2006

Question
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Followup To
Question -
Dear David

A friend and I got involved in a conversation about flight schedules and we had different views about what is a "departure time" in an airline schedule:
(1) I maintaned that it refers to take-off time, and my friend says (2) It is the time when the crew closes the door and the aircraft is ready to leave the passenger station.

Can you help determine who is right?

Thank you very much in advance for your help.
Answer -
Hi, Jose:

Thanks for your question:  Answer #2 is correct.  It is essentially the time the door is closed at the gate.  The reason for this is that there are a number of "gate holds" and the departing flights are held at the gate, sometimes for an hour or more, and their departure time is calculated from when the door closes...same with arrival at the gate (door opening is the arrival time).

I hope that this helps,

Dave NewMyer

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Thank you very much, and I should consider myself satisfied. But...
Just think that, by the same logic, "arrival time" should be the time the wheels of the airplane touch the ground, since many of the same problems that may happen between boarding time and take-off could conveivably happen between landing time and discharge of passengers at the gate.
I remember once having stood up for one hour at Heathrow, waiting for a bus to get to the airplane, as they seem to have run out of busses...
Am I being too fussy?
Best regards  

Answer
HI,

Thanks for the follow up question.  I should have quoted you chapter and verse.....sorry about that!  The answer IN THE USA (this may not be how it is calculated in other nations) is contained in CFR (Code of Federal Regulations) part 234.4 (e) which states:  "Actual arrival, departure and elapsed times shall be measured by the times at which the aircraft arrived at or departed from the gate or passenger loading area." Part 234 is entitled "Airline Service Quality Performance Reports" and is the responsibility of the US Department of Transportation, Office of the Secretary.  It specifies how airlines are to report on time performance nationally.

I hope that this clarifies my earlier answer.

Sincerely,

David A. NewMyer, Ph.D., Professor and Chair
Aviation Management and Flight
Southern Illinois University Carbondale
http://www.aviation.siu.edu