Scheduled and Actual times

[jackharr]

Published timetables are blocks to blocks, eg LGW dep 0510, AMS arr 0625 UTC (but given in local times for the public’s benefit).

Now if A/C leaves stand at 0510, it is considered to be “on time”. That’s fine. But if it touches down at say 0620, the arrival on the displays (and nowadays, available on line) is given as “5 minutes early”. Now at somewhere like AMS, the time to taxy in after a landing on 18R might be as much as 15 minutes so the aircraft arrives on the stand 10 minutes behind the scheduled time.

This practice of quoting departure time as being when the aircraft starts to taxy but quoting arrival time as when the aircraft touches down is inconsistent. I presume the airlines like this as are perceived as achieving a higher percentage of on-time departures and arrivals this way.

I raised this matter when I was flying 20 years ago but got no response other than “that is the way it is”. I am currently following my son’s line training and am disappointed that this, frankly dishonest, practice is still used.

[DaveReidUK]

Now if A/C leaves stand at 0510, it is considered to be “on time”. That’s fine. But if it touches down at say 0620, the arrival on the displays (and nowadays, available on line) is given as “5 minutes early”. Now at somewhere like AMS, the time to taxy in after a landing on 18R might be as much as 15 minutes so the aircraft arrives on the stand 10 minutes behind the scheduled time.

Can you give an example of an airport/airline that you consider to be guilty of this practice?

I ask because if you look at live arrivals info for an airport like Heathrow, for example, you will see a display showing entries like "LANDED 08:32".

That doesn't sound like anyone being dishonest, it's simply a statement of fact.

[Capetonian]

I don't know which criterion the airlines themselves use, but the MVT messages which are sent to the distribution systems show a 'landed' time and an 'arrived' time, the latter being the block time.

Example 1 : Last night's SA235 LHR - JNB where the MVT and the airport (ACSA) website show +/- the same landing time (1 minute difference)

* OPERATIONAL FLIGHT INFO * SA 235 -1 TU 02JUL
LHR ESTIMATED TIME OF ARRIVAL 0649 JNB
JNB AIRCRAFT LANDED 0643
ARRIVED 0652

SA235: London-Heathrow LANDED 6:44

Example 2: This morning's IB 3170 MAD-LHR where the airport arrivals and the MVT show the same 'landed' time of 0759.

08:20 IB3170 MADRID LANDED 07:59 Terminal five

* OPERATIONAL FLIGHT INFO * IB3170 0 WE 03JUL
MAD ESTIMATED TIME OF DEPARTURE 0645
LEFT THE GATE 0645
TOOK OFF 0655
ESTIMATED TIME OF ARRIVAL 0758 LHR
LHR AIRCRAFT LANDED 0759
ARRIVED 0815

[Sunnyjohn]

As I understand it, the aircraft flight time is from the moment the door is sealed before taxying prior to takeoff to the time the door is unsealed following taxying after landing. Is that correct?

[PAXboy]

My guess is that very, very, very few people believe corporates these days anyway. if it's a very small company - I believe them more as they have more to lose. But the big companies can always cover up / apologise / compensate for a mistake.

If a company say they are on time - that is historic and no ref to what might happen on the day. So I just ignore ANY publicity or advertising and that goes in ANY field of commerce. Oh and I ignore things the govt tell me they have done as well.

[DaveReidUK]

As I understand it, the aircraft flight time is from the moment the door is sealed before taxying prior to takeoff to the time the door is unsealed following taxying after landing. Is that correct?

http://www.pprune.org/spectators-bal...lculation.html

[PAXboy]

• Flight time
• Block time
• Passenger time
• Public relations time
• RyanAir time

Take your pick!

[RJ100]

At BACF we use Brakes off, at the start of the push back, to Brakes on when pulled on to stand. This is transmitted by ACARS to the company. We are not able to manipulate these figured. These times are what's shown on the BA website as the actual the of arrival.

[jackharr]

My original post was badly written and not quite I had meant to say. I didn’t intend to imply that particular airlines use a misleading way of using arrival times. But I did mean that airlines in general might be happy if the “system” suggests better arrival timekeeping than is actually the case.

Here is the sort of misleading confusion I had in mind.

From the Gatwick Live Arrivals
08:30 BA2262 KINGSTON EXPECTED 08:32

08:30 was the scheduled time to be on blocks. But the expected 08:32 was the ETA for landing.
(In fact one and a half holds were needed; it actually landed at around 08:38. That could hardly have been fed into the landing estimate so not complaining on that score.)

However the implication was that the flight was expected to be just 2 minutes late which was never going to be true. For the live arrival board to quote – and invite comparison – between two different things is misleading: it is not comparing like with like. If touchdown was expected to be 08:32, then it would have been far nearer the truth to say EXPECTED 8:40. This would therefore compare expected blocks time with scheduled blocks time.
(I accept that landing-to-blocks interval is a huge guess)

[Agaricus bisporus]

I don't think that what is displayed on an airport's information screens has anything to do with on time statistics, its just something the airport puts up for info of the public. It isn't a likely to be a definitive statistic.

[Sunnyjohn]

Thanks for the link to the thread, DR. I have read it twice and I am now clear that I am completely confused.

[jackharr]

...just something the airport puts up for info of the public

Let me give an example of how it misleads the public. I recently went (by car) to GLA to collect my daughter. Now parking at most airports can involve a significant walk to the terminal. My daughter is handicapped and cannot walk far and has to be accompanied by a carer. So I used the much closer dedicated drop off/pick up point but where however you cannot simply wait indefinitely. So it was important that I should arrive at the pick up point at the appropriate time. Had I simply taken the estimated time as being the gate time, I might have arrived too early and would have had to enter a “holding pattern” in my car. So times that are estimated landing times and not estimated gate times can mislead for Joe Public who doesn’t necessarily understand the difference. At GLA, the difference is trivial - only a matter of a few minutes - but at somewhere like AMS it is significant.

And of course, for some car parking, you have pay and display and have to guess how long you will need.

Confusion reigns as already noted by another contributor to this thread.

[ExXB]

I believe that the only airline that harps on about their OTP is a certain Irish based airline that frequents obscure and out of the way airports. Yes, their OTP is good, but it should be.

But they still compare themselves to AEA statistics that are at least five years old. The AEA stopped compiling them because it is really a useless statistic and just invited unfair comparisons.