Flight History Repositioning?

I'm trawling through the Flight history at the moment on a little project

Just noticed that a lot of the 'Assumed Flight Movements' are actually due to the history being in the wrong order.

Hence for VAEL at the beginning of November we have:
(*=Assumed)

1. 1 Nov: LHR - LAX
2. LAX - JNB *
3. JNB - LHR
4. 2 Nov LHR - JNB
5. 3 Nov JNB - LHR *
6. 4 Nov LHR - BOS
7. BOS - JNB *
8. JNB - LHR

I reckon this is because all the dates are LHR dates of arrival or departure e.g. the date the flight either leaves or arrives at LHR. Hence flight 3 actually arrived at LHR on the morning of 1/11 and took off for LAX in the PM. #5 is a phantom of #7 as it would have taken off from JNB on eve of 3/11 and arrived early on 4/11 ready to serve Boston in the afternoon.

The actual flight history for these 4 days would then read:

1. 31 Oct-1 Nov: JNB - LHR
2. 1 Nov-2 Nov LHR - LAX
3. 2 Nov: LAX - LHR *
4. 2 Nov-3 Nov: LHR - JNB
5. 3 Nov-4 Nov: JNB - LHR
6. 4 Nov LHR - BOS

This seems to work better. Does this make sense?

Phil (Buffy)

[Pete]

Yes - looks like you are correct. When the order was switched (so the latest flights were at the top of the list rather than the bottom), I hadn't realised the effect it would have on the assumed flights.

The dates are indeed LHR/LGW dates, since the ACARS logs used to collate the info are all UK. I'll need to do a bit of brain-melting work on the logic behind the list to get everything back into order - but thanks for pointing out the error

[Pete]

Think I've got is sussed - it didn't take quite as long as I thought, but did involve totally re-scripting the logic behind the route history.

It now takes into account the fact flights are recorded in the UK, and therefore the departure date is adjusted when the arrival is + 1 day. It compares the log with a VS timetable to work out which route is which, and the scheduled time of departure - so if a flight goes off to Boston from London, it knows that happened before the return flight to London that night.

Anyways, the new page is live and should be producing the correct results. Please let me know if there are any errors!

Pete

Looks good - I like the addition of the time from the schedule - wish it was the actual departure time

One small thing - on the 'To' side of the listing the airport codes do not tally with the stated destination on the 'Assumed' flights - I reckon you're reusing the same variable as the code and not clearing out the buffer [8D]

Phil (Buffy)

[Pete]

I may be missing something, but it looks right to me. Remember, the flights are listed in reverse order (so the latest flights are at the top), so you have to read the routes (and assumed flights) backwards.

Pete

quote:Originally posted by pixuk
I may be missing something, but it looks right to me....
Pete

If you check out this extract for G-VAEL...

quote:From Aircraft History

28 Nov 04 8:20 AM VS018 EWR New York Newark LHR London LHR
LOS Lagos EWR LHR
27 Nov 04 10:00 PM VS651 LHR London LHR LOS Lagos
EWR New York Newark LHR LOS
27 Nov 04 8:30 PM VS017 LHR London LHR EWR New York Newark
27 Nov 04 10:25 AM VS652 LOS Lagos LHR London LHR
LHR London LHR LOS LHR
26 Nov 04 8:20 AM VS018 EWR New York Newark LHR London LHR

Sorry can't format it quite right.

You can see that for those flight that are 'Assumed' the three letter airport code is followed by another 3 letter code rather than the airport name as with the actual flights.

Phil (Buffy)

[Pete]

[:o)] Sorry - totally word blind there. Obvious when you pointed it out.

Ok, fixed that. I was just using the wrong dimension of the array that holds the flights.

Pix

Oooh spotted something else.

Again on VAEL

LOS Lagos EWR New York Newark
27 Nov 04 10:00 PM VS651 LHR London LHR LOS Lagos
EWR New York Newark LHR London LHR
27 Nov 04 8:30 PM VS017 LHR London LHR EWR New York Newark

The Lagos flight is showing as 27th but I'm sure its 26th to fit in with other movements - probably not minusing the day from the date - just the time.

Then lower down...

23 Nov 04 4:00 PM VS250 LHR London LHR SHA Shanghai
EWR New York Newark LHR London LHR
23 Nov 04 4:00 PM VS001 LHR London LHR EWR New York Newark

Two places at once?

Maybe we should take this off-line [:I]

Phil (Buffy)

[Pete]

Although the Lagos flight from London arrives the next day in Lagos, the ACARS would have been recorded in London on the departure date - so that should be correct. For the return flight, it arrives the same day, so no adjustment required.

VS651 LHR-LOS 22:00 05:45*
VS652 LOS-LHR 10:25 15:55

For the example you're looking at, G-VAEL flew back from EWR on the 26th as the VS18 - departure 08:20am, arrival 20:00 same day. After a 2 hour turnaround, it would have left LHR at 22:00 to Lagos, arriving in the morning on the 27th, then back to London at 10:25 (arriving 15:55) ready for the 20:30 VS17 to EWR again.

For the other error you mention, that looks like an incorrect entry in the ACARS data. Unfortunately (although not too common) they occassionally creep into the data because there's a human element on the part of the good folk who sit under the flightpath listening into this stuff, and recording it in ACARS logs to share with the world. There's no real way to account for oddities such as that.

Pix

Sorry Pix,

Second guessing myself and it's been a long day [B)]

Think I was getting confused by the last entry as it had a flight from LHR to LOS on the evening of the 27th - followed by two missing flights (I assume) LOS - LHR and LHR - EWR and then still had a flight from EWR on the morning of the 28th - So I guess I figured day missing. Its prob. more likely an error in the data as you suggested with the other data.

As I go through the data I'll let you know if I find anything else strange

Thanx for sorting it out so quickly though - appreciate it much.

Phil (Buffy)