FPL filing, departure time: EOBT or TOT?
Thread Starter
Joined: Sep 2013
Posts: 19
Likes: 0
From: NQZ
FPL filing, departure time: EOBT or TOT?
Hi,
recently we had some debates over what should be considered as a departure time in ICAO FPL format.
In the Item 13 we insert the departure time, which should be off block time as per explanation given in Skybrary. I failed to find any respective ICAO definition, but no doubts here: at least in Europe, if you file ETD for 1400UTC, it will be shown as EOBT 1400 UTC.
The estimated elapsed time though is as per ICAO definition as the time required from take-off to arrive over that designated point, so the time enroute, or trip time, is calculated for the time frame between take off and arriving over navaid.
That means if we want to calculate the ETA, we can not just add the ETE to ETD value, which appears to be a common mistake, but rather ETA = ETD+(taxi time)= TOT as take off time.
TOT + ETE = ETA.
The problem is, neither the take off time nor taxi time are stated nowhere in the FPL, so where exactly should we start to count the EET?
I mean Eurocontrol provides some taxi time statistics plus most airlines have their own, but then again, they are not stated in the FPL, so if you don't know it, you can' t really define the ETA.
recently we had some debates over what should be considered as a departure time in ICAO FPL format.
In the Item 13 we insert the departure time, which should be off block time as per explanation given in Skybrary. I failed to find any respective ICAO definition, but no doubts here: at least in Europe, if you file ETD for 1400UTC, it will be shown as EOBT 1400 UTC.
The estimated elapsed time though is as per ICAO definition as the time required from take-off to arrive over that designated point, so the time enroute, or trip time, is calculated for the time frame between take off and arriving over navaid.
That means if we want to calculate the ETA, we can not just add the ETE to ETD value, which appears to be a common mistake, but rather ETA = ETD+(taxi time)= TOT as take off time.
TOT + ETE = ETA.
The problem is, neither the take off time nor taxi time are stated nowhere in the FPL, so where exactly should we start to count the EET?
I mean Eurocontrol provides some taxi time statistics plus most airlines have their own, but then again, they are not stated in the FPL, so if you don't know it, you can' t really define the ETA.
Joined: Jun 2008
Posts: 80
Likes: 0
From: Some hotel
Departure time, STD is always off block time as per the ATC filing. Then there are some airports that publish TSAT and TOBT from there. Eurocontrol normally has a standard taxi time for each airport normally 10-20 minutes, but regardless of that the EET always starts at takeoff. Eurocontrol will see both actual OBT and TOT.
Some flight plan systems assume a certain standard taxi time to estimate the ETA from the STD and even the ETA at the alternate airport for info only, but I fail to see why you would need that as it rarely will be accurate.
Some flight plan systems assume a certain standard taxi time to estimate the ETA from the STD and even the ETA at the alternate airport for info only, but I fail to see why you would need that as it rarely will be accurate.
Joined: Mar 2011
Posts: 105
Likes: 0
From: Italy
I have a question just as spectator...
I assume a rotation MXP-LGW-MXP , the aircraft is scheduled to arrive at 10.00 and departs again at 10.30. If the incoming aircraft arrives at 10.05 by default the Estimated departure time will be 10.35?
I assume a rotation MXP-LGW-MXP , the aircraft is scheduled to arrive at 10.00 and departs again at 10.30. If the incoming aircraft arrives at 10.05 by default the Estimated departure time will be 10.35?
Joined: Mar 2011
Posts: 105
Likes: 0
From: Italy
Just a simple example.
Flight rotation, MXP-LGW-MXP
MXP-LGW scheduled on blocks time: 10.00 Actual on blocks time: 10.10
LGW-MXP Scheduled off blocks time 10.30 my question is by default this flight estimated off block time is delayed at 10.40 due to late arrival of the incoming aircraft
Flight rotation, MXP-LGW-MXP
MXP-LGW scheduled on blocks time: 10.00 Actual on blocks time: 10.10
LGW-MXP Scheduled off blocks time 10.30 my question is by default this flight estimated off block time is delayed at 10.40 due to late arrival of the incoming aircraft
Only half a speed-brake
Joined: Apr 2003
Posts: 4,459
Likes: 136
From: Commuting not home
Every flight is treated as a stand alone movement - from ATC that is (which I am not). So, unless somebody amends the FPL or enter new estimated off block, then no.
One of the serious issues, when dealing with irregularities from the airlines' side, is telling the customers the flight is delayed. Some will be gone in an instant from the gate only to be seen again 10 minutes after the new, delayed departure time you declared so honestly.
One of the serious issues, when dealing with irregularities from the airlines' side, is telling the customers the flight is delayed. Some will be gone in an instant from the gate only to be seen again 10 minutes after the new, delayed departure time you declared so honestly.
