sankaps
Topic Author
Posts: 1692
Joined: Fri Jan 04, 2008 6:51 am

Airlines Definition Of On-time In Various Places?

Tue Mar 13, 2012 1:17 pm

Hi all,

Can anyone tel me definitively how on-time performance is defined by airlines in the US, UK, Germany, Singapore, UAE, Japan, India, China, etc? Is there a standard definition? Are delays due to weather, ATC, etc excluded? Are cancelled flights excluded?

Essentiall, is there a gobally accepted standard definition?

Thanks,

Sankaps.
 
boeing773W
Posts: 46
Joined: Sat Mar 10, 2012 9:03 am

RE: Airlines Definition Of On-time In Various Places?

Tue Mar 13, 2012 3:08 pm

I don't have a source for this and cannot say for sure that it applies equally in every country, but I seem to recall that a flight which operates within 15 minutes of its schedule is considered "on time"- i.e. within 15 minutes before or after. A flight over 15 minutes late is considered "delayed" and under 15 minutes "early".

It would be interesting to get other people's responses, perhaps with some authority.
 
Rdh3e
Posts: 2767
Joined: Wed Mar 30, 2011 2:09 pm

RE: Airlines Definition Of On-time In Various Places?

Tue Mar 13, 2012 6:29 pm

Quoting boeing773W (Reply 1):
I don't have a source for this and cannot say for sure that it applies equally in every country, but I seem to recall that a flight which operates within 15 minutes of its schedule is considered "on time"- i.e. within 15 minutes before or after. A flight over 15 minutes late is considered "delayed" and under 15 minutes "early".

It would be interesting to get other people's responses, perhaps with some authority.

The standard for departure is D:00. So departing by the time the flight is scheduled to leave, some measure that by when you kick the brakes, some by when you move the aircraft.

The real standard for on time though at least in the US is A:14, arrival within 14 minutes of scheduled arrival time.

[Edited 2012-03-13 11:29:44]
 
roseflyer
Posts: 9606
Joined: Fri Feb 13, 2004 9:34 am

RE: Airlines Definition Of On-time In Various Places?

Tue Mar 13, 2012 6:59 pm

When I was working reviewing reliability numbers at an airline, there were 5 numbers that we used.

A14: Arrival within 15 minutes of scheduled arrival time for all flights.
D0: Airplane parking brake is released at departure time, which is filtered to remove weather, airport operations, passenger loading, catering, etc
D15: Airplane is within 15 minutes of scheduled departure time (filtered as above)
D120: Airplane is within 120 minutes of scheduled departure time (filtered as above)
Cancellations: Canceled for airplane maintenance and mechanical reasons including crew time out due to airplane maintenance, but not weather or lack of crew availability

The reason for so many metrics is that each of them is evaluated for different reasons.

The metric reported to the public is A14 and shows the overall health of the airline. This metric can be used to measure performance of all divisions from crew operations to maintenance to dispatch. It also shows delays caused by cascading problems in the schedule. Padding the schedule helps this number, but padding the schedule comes at the cost of paying higher crew rates and lower fleet utilization.

D0 is the goal from an aircraft availability point. The airplane is ready to fly with no mechanical problems. Airport operations delays can happen, but the airplane should be ready to go.

D15 is important because items causing mechanical delays less than 15 minutes are understandable. They typically are for deferring a part or cycling power quickly to a system. They do not require intensive maintenance and show that the airline is healthy at addressing a maintenance problem from the second the plane blocks into the gate rather than waiting until departure is imminent.

D120 is useful because it shows overall how reliable are the airplanes. Poorer reliability can be fixed by improving maintenance programs. D120 are delays that usually result from a genuine mechanical problem and not about simple deferral items.

Cancellations are about maintenance but also spares availability, dispatch's ability to swap airplanes and crew, etc.
If you have never designed an airplane part before, let the real designers do the work!
 
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zippyjet
Posts: 5089
Joined: Tue Sep 04, 2001 3:32 pm

RE: Airlines Definition Of On-time In Various Places?

Tue Mar 13, 2012 9:09 pm

With us, if it says departure at 1915, it's 1915; wheels rolling (off the gate). All passengers have to be on board no later than 10 minutes prior to published departure time. If we are late (CSA/Ramp/In Flight) you better come up with the reason and document.
Enough times late and there's a secret room    kidding on the secret room. From a Department of transportation standpoint (DOT) delays more than 15 minutes are considered major delays and count against the carrier involved.
I'm Zippyjet & I approve of this message!

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