Flight Plan Differences
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Flight Plan Differences
On a number of occasions recently it has become apparant that my acknowledged(by CFMU)flight plan differs from the one which enroute ATC thinks that i'm following - mainly in the UK but occasionally over Continental Europe. Is there some fundamental problem here or are these just a series of one-off events?
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It can depend on what levels you are flying at. For example, and a/c flying from Amsterdam to Coventry at FL100 will file to route via LAM VOR. Given that this is the busiest Holding Stack for Heathrow, the a/c will be re routed in the majority of cases via CLN then BPK. Likewise if you file at a certain level then request a higher one (or indeed lower) then you may get re routed because of the base of controlled airspace.
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If I understand your question correctly oracle, I believe that CFMU can (and do) change FPL details in order to enable a particular slot to be issued. I am a simple airport-type controller so it doesn't affect me greatly but I have often wondered how crews get to know about these changes - and never been able to get an authoritative answer.
Is there some fundamental problem here or are these just a series of one-off events?
I've certainly had issues that fit the description you give, omega. In my case, it was usually a routing via CLN SASKI COA which complies with the RAD and is accepted by CFMU, but seems to confuse both London and Brussels whose systems indicate a DVR KOK routing. To their credit, both were extremely helpful after the event in assisting to try to find the underlying problem, though I'm not sure if anything is resolved. There seems to be an occasionally variance between the RAD and letters of agreement between centres.
but I have often wondered how crews get to know about these changes
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The FPL route in the cockpit and the FPL acknowledged by IFPU should be the same.
That's not to say that ATC cannot issue a clearance along a slightly different route for their own reasons.
There is not enough info from the above posts to give a definitive answer but if you can supply the following info:
Date of Flight, c/s and city pair
I can try to get an explanation.
flowman
That's not to say that ATC cannot issue a clearance along a slightly different route for their own reasons.
There is not enough info from the above posts to give a definitive answer but if you can supply the following info:
Date of Flight, c/s and city pair
I can try to get an explanation.
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Does your Ops put 'IFPS Re-route accepted' in the FPL?
This is one possible reason why it has been ACK'ed but turns out to be different (as Spitoon has alluded to).
Another reason: If a FPL has been 'referred for manual intervention' (i.e. UK computer says 'no') the route or level may have to be altered, but should always be accompanied by a note on the strip to say what has been filed.
This is one possible reason why it has been ACK'ed but turns out to be different (as Spitoon has alluded to).
Another reason: If a FPL has been 'referred for manual intervention' (i.e. UK computer says 'no') the route or level may have to be altered, but should always be accompanied by a note on the strip to say what has been filed.
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In my case, it was usually a routing via CLN SASKI COA which complies with the RAD and is accepted by CFMU, but seems to confuse both London and Brussels whose systems indicate a DVR KOK routing
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I feel it happens regularly that the route that is accepted by CFMU is not allowed in the Letter of Agreement between the ATC units concerned. Let's hope this will be a disappearing problem...
And just a bit more on the SASKI - COA routeing.
Straight out of the Letter of Agreement between LTC and Brussels ACC :
Flights from LTC to EBBU on L179 (SASKI - COA):
Flights with destination EBOS, EBBR TMA(EBBR, EBMB, EBAW, EBCV) and EBCI may be accepted via L179. FL170 will be the maximum level. An approval request is required for traffic above FL115.
Even though the use of L179 is limited to the flights with the specified destinations, we get a lot of approval requests for overflights too...
And just a bit more on the SASKI - COA routeing.
Straight out of the Letter of Agreement between LTC and Brussels ACC :
Flights from LTC to EBBU on L179 (SASKI - COA):
Flights with destination EBOS, EBBR TMA(EBBR, EBMB, EBAW, EBCV) and EBCI may be accepted via L179. FL170 will be the maximum level. An approval request is required for traffic above FL115.
Even though the use of L179 is limited to the flights with the specified destinations, we get a lot of approval requests for overflights too...
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There is a requirment for the flight plan to be included with the paperwork for the flight. We also include the ack message also so that pilots know the flight plan as shown is accepted.
When we get the weather and notams briefing (much closer to EOBT than the filing time), we ask for a printout of the CFMU route points which will include any re-routing by flow.
The problem is that when an ACC for local reasons change the routing they do not let the CFMU know and consequently you get a route different from what you were expecting.
We checked this out and the decision for the time being is that;
a) The filed flight plan is not being amended by the ACC and thus in the radio failure senario (prior to the new clearance) you go as filed.........(even if filed and ACK'd at FL100 via LAM). The ACC are aware of this and note it on the strip for the controller. They will not have a problem.
b) Route changes are treated like any directs or shortcuts enroute and very few make a significant effect on the fuel burn - at least not one that is outside the natural contingency.
c) Where regularly pilots find that the filed route and the actual route clearance are diffeent they include such info on the voyage report and the goold old ATC liasion person
checks with ACC, CFMU etc to see if it is better to file a new route.
Regards,
DFC
When we get the weather and notams briefing (much closer to EOBT than the filing time), we ask for a printout of the CFMU route points which will include any re-routing by flow.
The problem is that when an ACC for local reasons change the routing they do not let the CFMU know and consequently you get a route different from what you were expecting.
We checked this out and the decision for the time being is that;
a) The filed flight plan is not being amended by the ACC and thus in the radio failure senario (prior to the new clearance) you go as filed.........(even if filed and ACK'd at FL100 via LAM). The ACC are aware of this and note it on the strip for the controller. They will not have a problem.
b) Route changes are treated like any directs or shortcuts enroute and very few make a significant effect on the fuel burn - at least not one that is outside the natural contingency.
c) Where regularly pilots find that the filed route and the actual route clearance are diffeent they include such info on the voyage report and the goold old ATC liasion person
checks with ACC, CFMU etc to see if it is better to file a new route.Regards,
DFC
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Flowman
A recent example to hand is EGSC to EGPN 11 Jan 08 c/s MCE10A. It became apparant that ATC were using a different hymn sheet when we were transferred to Scottish (round about POL, I think) and weren't able to make contact for a short while due to R/T congestion. Continuing with our acknowledged FPL route in the meantime was obviously a surprise to Scottish who subsequently read out a completely different route from the one we had.
As someone else noted, it would probably only become a problem in the event of R/T failure - giving ATC more difficulty in predicting the route we were likely to follow.
On a similar topic - it quite often seems impossible to get a FPL accepted by CFMU for a route which is known to be used by ATC (eg northbound across France to GUBAR or AKIKI) and which one eventually ends up following anyway.
Any ideas why that might be so?
A recent example to hand is EGSC to EGPN 11 Jan 08 c/s MCE10A. It became apparant that ATC were using a different hymn sheet when we were transferred to Scottish (round about POL, I think) and weren't able to make contact for a short while due to R/T congestion. Continuing with our acknowledged FPL route in the meantime was obviously a surprise to Scottish who subsequently read out a completely different route from the one we had.
As someone else noted, it would probably only become a problem in the event of R/T failure - giving ATC more difficulty in predicting the route we were likely to follow.
On a similar topic - it quite often seems impossible to get a FPL accepted by CFMU for a route which is known to be used by ATC (eg northbound across France to GUBAR or AKIKI) and which one eventually ends up following anyway.
Any ideas why that might be so?
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A recent example to hand is EGSC to EGPN 11 Jan 08 c/s MCE10A. It became apparant that ATC were using a different hymn sheet when we were transferred to Scottish (round about POL, I think) and weren't able to make contact for a short while due to R/T congestion.
At the time of the flight, EGPN arrivals were treated as EGPH inbounds by Scottish and transferred to Edinburgh Radar either on a heading towards their inbound fix (TARTN) or on the pilot's own navigation direct to TARTN, EDN, or EGPN.
The benefits of this tactical rerouting are to ensure the aircraft enters less sectors (freeing up capacity), with the spin off of a more direct routing to EGPN for the pilot.
This procedure has now changed and Edinburgh no longer work this traffic but it is handled internally by Scottish. You'll probably still get put on a direct track towards EGPN, but on a more efficient descent profile.
Of course that might not be what you have filed, and the longer route should still be available if you really want it
I feel it happens regularly that the route that is accepted by CFMU is not allowed in the Letter of Agreement between the ATC units concerned. Let's hope this will be a disappearing problem...
Regarding SASKI-COA, the LoA you quote doesn't make the situation below FL115 explicit. L179 is a normal airway with no RAD restrictions in that direction. There is no RAD restriction on destination. The Brussels supervisor (was it you?) with whom I spoke last time quoted the LoA (and informally suggested that you tend to accept anything London sends your way anyway) but there doesn't seem to have been any move towards consistency between LoA and RAD.
If the problem disappears, I'd be grateful if it disappeared in the direction of the LoA being made consistent with the current RAD (i.e. all flights permitted below FL115).
When we get the weather and notams briefing (much closer to EOBT than the filing time), we ask for a printout of the CFMU route points which will include any re-routing by flow.
...
a) The filed flight plan is not being amended by the ACC and thus in the radio failure senario (prior to the new clearance) you go as filed.........(even if filed and ACK'd at FL100 via LAM).
...
a) The filed flight plan is not being amended by the ACC and thus in the radio failure senario (prior to the new clearance) you go as filed.........(even if filed and ACK'd at FL100 via LAM).
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Omega, I've just come off nights and will be back at work on Friday.
I will try to get some answers for you then and to some of the other issues mentioned here.
Pprune Radar seems to have covered the answer though.
I will try to get some answers for you then and to some of the other issues mentioned here.
Pprune Radar seems to have covered the answer though.
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PPRuNe Radar/Flowman
Thank you for all that. Obviously, always happy to accept 'directs' when available.
I no longer have easy access to the paperwork for that flight but, from (somewhat ageing) memory, the ACK FPL went something like: DCT MAMUL UL613 HALIF UN590 MARGO UN601 TLA DCT EDN DCT. I was pretty sure we wouldn't be routed that way, particulary as the initial clearance was towards BKY(as usual). It seems as if someone in operational ATC system changes these from the CFMU version (often to a more practical routing) but the crew only find out about it by chance.
Another thought on this general subject - why can't the CFMU website, which we use for checking out FPL's before filing, be programmed to advise what is possible rather than just saying what can't? I and many others, i'm sure, waste lots of time trying to iron out the bugs in a proposed route (incidentally, this is using a commercial flight planning system).
Thank you for all that. Obviously, always happy to accept 'directs' when available.
I no longer have easy access to the paperwork for that flight but, from (somewhat ageing) memory, the ACK FPL went something like: DCT MAMUL UL613 HALIF UN590 MARGO UN601 TLA DCT EDN DCT. I was pretty sure we wouldn't be routed that way, particulary as the initial clearance was towards BKY(as usual). It seems as if someone in operational ATC system changes these from the CFMU version (often to a more practical routing) but the crew only find out about it by chance.
Another thought on this general subject - why can't the CFMU website, which we use for checking out FPL's before filing, be programmed to advise what is possible rather than just saying what can't? I and many others, i'm sure, waste lots of time trying to iron out the bugs in a proposed route (incidentally, this is using a commercial flight planning system).
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@Bookworm
After some research, I don't think this SASKI - COA thing has a simple answer. I understand the reasoning of the Letter of Agreement between LTC and Brussels ACC (SASKI - COA is opposite to the departures from EBBR/EBMB and EBAW).
So, the LoA is not clear, the RAD says nothing and the Belgian AIP gives the restriction above FL115 only.
I'll have a talk with someone on wednesday, let's see what he says...
An additional problem might be that about 2/3 of the airway between SASKI and COA is in the Dutch FIR and is delegated to Brussels ACC.
Anyway, we are going a bit off topic here but if you want i'll PM you anything I can dig up.
OH, and no, I'm not a supervisor, just a regular ACC ATCO
After some research, I don't think this SASKI - COA thing has a simple answer. I understand the reasoning of the Letter of Agreement between LTC and Brussels ACC (SASKI - COA is opposite to the departures from EBBR/EBMB and EBAW).
So, the LoA is not clear, the RAD says nothing and the Belgian AIP gives the restriction above FL115 only.
I'll have a talk with someone on wednesday, let's see what he says...
An additional problem might be that about 2/3 of the airway between SASKI and COA is in the Dutch FIR and is delegated to Brussels ACC.
Anyway, we are going a bit off topic here but if you want i'll PM you anything I can dig up.
OH, and no, I'm not a supervisor, just a regular ACC ATCO
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Omega,
My colleague in Flight Planning has done some investigation using the information you supplied and reports as follows:
-EGSC1600
-N0403F300 DCT DTY DCT STOAT UL613 TLA/N0404F290 DCT EDN DCT
-EGPN0100
This route was not accepted by the computer due to DCT LIMIT being exceeded on the segment DTY DCT STOAT .
As the FPL contained RMK/IFPS REROUTE ACCEPTED, the IFPS operator corrected the route to:
-N0403F300 DCT MAMUL UL613 FINDO UP600 PTH DCT
This is the final route that was accepted, that became valid both to FPS and FLOW, that was transmitted back to the FPL originator in the ACK and finally, that was also tramsmited to all ACCs concerned.
If the cockpit had anything else that would indicate a problem between the FPL filer and the cockpit crew.
In ACC: anything different from the route above is the result of changes performed by the ACC itself. ACC received from CFMU a route identical to the one in the ACK.
regards,
flowman
My colleague in Flight Planning has done some investigation using the information you supplied and reports as follows:
-EGSC1600
-N0403F300 DCT DTY DCT STOAT UL613 TLA/N0404F290 DCT EDN DCT
-EGPN0100
This route was not accepted by the computer due to DCT LIMIT being exceeded on the segment DTY DCT STOAT .
As the FPL contained RMK/IFPS REROUTE ACCEPTED, the IFPS operator corrected the route to:
-N0403F300 DCT MAMUL UL613 FINDO UP600 PTH DCT
This is the final route that was accepted, that became valid both to FPS and FLOW, that was transmitted back to the FPL originator in the ACK and finally, that was also tramsmited to all ACCs concerned.
If the cockpit had anything else that would indicate a problem between the FPL filer and the cockpit crew.
In ACC: anything different from the route above is the result of changes performed by the ACC itself. ACC received from CFMU a route identical to the one in the ACK.
regards,
flowman
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Bookworm,
Prior to flight we have to get a new printed flight log from ops which will include the new route and of course the new fuel figures.
Getting a new printout is far quicker than amending the old one and working out the new fuel requirements etc.
It also means that the FMS waypoints can be crosschecked with the PLOG.
---------
I think that the example of the Dundee inbound is a very good one;
The pilot wants to route one way
The IFPS system route him/her another way
The ACC then change the routing again because being in the upper air to findo does not work in terms of getting the aircraft down for Dundee and the IFPS does not take into account the availability of LARS from Leuchars whic is very handy some Dundee is non-radar.
Regards,
DFC
DFC, are the instructions to fly the route as filed, or the route as indicated on the CFMU point-by-point calculation?
Getting a new printout is far quicker than amending the old one and working out the new fuel requirements etc.
It also means that the FMS waypoints can be crosschecked with the PLOG.
---------
I think that the example of the Dundee inbound is a very good one;
The pilot wants to route one way
The IFPS system route him/her another way
The ACC then change the routing again because being in the upper air to findo does not work in terms of getting the aircraft down for Dundee and the IFPS does not take into account the availability of LARS from Leuchars whic is very handy some Dundee is non-radar.
Regards,
DFC
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Bookworm has alluded to one of the problems that can arise when a flight plan contains point to point DCT routeings. Provided the distance between the two waypoints is within IFPS limits then a flight plan can be accepted that may not be on an acceptable route to a particular ATC centre. An amended route may be input at the centre - in the UK this should have a remark entered on the flight strips showing what had been filed by the operator.