Resolved Cumulative times wrong


Well-known member
Feb 4, 2007
I have 365 days of data in APDL now, and I validated all the block times day by day. Everything matches Crewtrac.

So why are all the cumulative limits off? Let's just start with 100/672. I checked the 28 day totals in excel and Crewtrac is correct. APDL is wrong.

Here are screenshots:

This is the top of the legality page showing when the data was computed. I navigated to the legality page from tomorrow's trip (2/9)


Below it shows the 100/678 limit as 54:50.


Crewtrac shows 49:56:


In excel I also calculate 49:56 from the end of tomorrow's trip


The only thing I can figure is that instead of calculating tomorrow's legality, which it obviously SHOULD be doing, instead it is looking back from THIS moment on 2/8, which is when it says the calculation is being made. BUT EVEN THAT IS WRONG! THAT SHOULD BE 54:22, AND APDL SHOWS 54:50, 28 MINUTES OFF! There are no segments that are 28 minutes during this period.

All the other cumulative limits (1000/365, 190/678 and 60/162) are significantly off, as well. I also verified all block time and FDP totals. I just thought I'd start with the 100/678.

What is going on here?
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The cumulative time page in RAH crewtrac has bugs from what scheduling says. They don't even use that for our legality.

I wouldn't trust it 100%.

I have had a few things happen on the dash trash here at RAH. RTG's and other stuff that don't count against my block and the crewtrac page shows that it does.

Example RTG from 3 trips ago. My RTG was 30 minutes and we returned to gate and cancelled due to MX. Didn't fly another lag that day.

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That is not the case. As you can see, I verified all the calculations. There are no issues with RTGs. Crewtrac is 100% correct. Both crewtrac and APDL have the same block times. The math is correct on crewtrac. Somehow, APDL is making a different calculation. Here are the block times from APDL if you want to compare with above from crewtrac and my calculations in excel.


Also, BTW, if there is an rtg, it DOES counts towards block time IF the airplane moved under its own power with the intention of flight. It just doesn't count as a segment for max FDP calculations.


"Q-45. A flight pushes back and taxies to the runway under its own power with the intention of flight. Before taking off, the flightcrew is notified that the flight is canceled. Is the taxi time counted as flight time?

A-45. Yes, because the flight moved under its own power with the intention of flight. However, the cancellation of the segment could change the FDP limit so the FDP Table should be reviewed to determine if the FDP is changed."
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My ALPA guide says no it doesn't.

Q-45. A flight pushes back and taxies to the runway under its own power with the intention of flight. Before taking off, the flight crew is notified that the flight is canceled and the aircraft returns to the gate. Is the taxi time counted as flight time?

A-45. No, because there was no takeoff and landing. However, this could change the FDP since the segment was not flown.
Just to eliminate as many possibilities as possible, do you have any entries during that period that are entered as something OTHER than "block"?
I just found that one. Interesting. The RAH guide with the same question is dated after that and says it IS counted as flight time. I need to research this one a little bit more, but my last RTG WAS counted as flight time.

There is one RTG, but it is counted as block in the summary and that is definitely not the discrepancy, as it is 1:58.

How does APDL do the 168 look back?. Does it start at the end of the last flight on the given day and then look back 678 hours, splitting any flight segment that might straddle the chosen FDP end minus 168? In other words if you look back 28 days from the chosen day and time and there is a flight in progress at that specific minute, does it take just the applicable portion of that flight, Or use the whole flight?
All good. Figured it out. Everything matches now. The discrepancy was because unbeknownst to me, at the time, was that the upcoming day already showed 4:54 of cancellations which were not included in the crewtrac cumulative summary. I should have seen that the current day only showed 2:45 of scheduled block.

Had another discrepancy today due to the fact that crewtrac was using updated estimate times instead of scheduled for the first 2 legs today.

Both were crewtrac induced problems. APDL good. Crewtrac bad. Also noticed that crewtrac appears to only show the last 27 days, not 28 for their so called 672 calculation. Calculating for 2/9 look back, shouldn't it go back to 1/12?
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Good to hear that APDL is correct when crewtrac is wrong.

This is precisely why we created APDL. It's very good and important that we all have confidence in the calculations that APDL is providing us so when there's a discrepancy, we know which one to trust.

So despite the confusion, pointing out things like this and taking a closer look with a fine toothed comb is important and helpful. Thanks for helping us clear it up.