Wrong Flight Path

[Guest jeffg]

I was flying yersterday from KORD to EGPK in Scotland and after I left the mainland was told that I was off my route and RC direction was 275 and I was on a course of 095.The course RC wanted me to fly was in wrong direction.I looked at the MS flight plan that was loaded and 275 was no where to be found.What caused this problem? Jeff

[nobleord 17]

Hi Jeff,Can you post the flight plan that you used for this flight. Since you were turned in the opposite direction (180 degrees) it sounds like you may have missed a waypoint and RC was turning you back towards it.

[Guest Chese]

I had a similar issue flying KBOS to EGLL. I think RC doesnt handle waypoints very far apart properly.

[PeteP 2]

Jeff,Bryan is correct - you missed a checkpoint (waypoint). The big clue is the 180 degree turn RC wants you to do to reach it. Remember, you're required to pass within 2nm in the departure phase and within 5nm in the en-route phase to be credited with a checkpoint.To confirm this is what has happened, compare the waypoint RC thinks is next (you'll find this at the top of the advdisp display) with what your FMC, GPS or whatever you're using for navigation thinks is next. If they're different, that's your problem. The solution if this happens in the en-route phase of your flight is to select the "Dir Chkpoint" item from the advdisp menu (you'll find it on page 2 by pressing the "next" key) and request a direct route to whichever waypoint your FMC/GPS etc. thinks is next. Problem solved.Pete

[PeteP 2]

I think RC doesnt handle waypoints very far apart properly.I don't think that's the issue in this case - see my reply to Jeff. However, it is something that's being worked on for a future release and beta team members have already carried out successful long distance great-circle track test flights.You're only likely to experience problems with the current version if your waypoints are more than about 300nm apart. If you try to keep your flight plan waypoints to no more than 250nm apart, you won't see the problem at all and this restriction should be more than adequate for most flight plans - I have, though, heard of a user trying to fly a "flight plan" which just consisted of EGLL DCT KJFK and that sort of thing really does give the current version a headache!If you do have to fly with waypoints more than, say, 300nm apart, the workaround is to increase the permitted heading deviation on the Radar Contact Options page - the default is 15 degrees. You can work out the amount of deviation that may be needed by comparing the track RC expects you to follow between waypoints (shown on the top line of the advdip display window)with that expected by your FMC, GPS or whatever. The other possibility when you have a long distance between waypoints is to ignore the FMC/GPS and follow the track information provided by RC instead - you'll still get where you're going and ATC won't yell at you.Pete

[Guest jeffg]

Here is the flightplan using FSBuild 2.2title=KORD to EGPKdescription=KORD, EGPKtype=IFRroutetype=3cruising_altitude=39000departure_id=KORD, N41* 58.46', W087* 54.15',+000666.00departure_position=PARKING 175destination_id=EGPK, N55* 30.10', W004* 34.31',+000066.00departure_name=CHICAGO_OHARE_INTLdestination_name=PRESTWICKwaypoint.0=KORD, A, N41* 58.46', W087* 54.15', +000000.00, waypoint.1=PETTY, I, N42* 49.38', W087* 38.02', +08000.00, waypoint.2=SSM, V, N46* 24.43', W084* 18.53', +35000.00, waypoint.3=DOTTY, I, N50* 38.00', W055* 35.00', +37000.00, waypoint.4=5248N, I, N52* 00.00', W048* 00.00', +39000.00, waypoint.5=5441N, I, N54* 00.00', W041* 00.00', +39000.00, waypoint.6=5532N, I, N55* 00.00', W032* 00.00', +39000.00, waypoint.7=5624N, I, N56* 00.00', W024* 00.00', +39000.00, waypoint.8=5615N, I, N56* 00.00', W015* 00.00', +39000.00, waypoint.9=NURSI, I, N54* 57.44', W009* 30.00', +39000.00, UN552waypoint.10=24DUB, I, N55* 05.15', W008* 34.11', +39000.00, UN552waypoint.11=TURLU, I, N55* 16.57', W006* 59.17', +24000.00, UN552waypoint.12=MAC, V, N55* 25.48', W005* 39.01', +11000.00, waypoint.13=EGPK, A, N55* 30.10', W004* 34.31', +000000.00, I flew the waypoints right and heard the dings when I passed them between dotty and waypoint 4 is when I was told not on route of flight. Jeff

[PeteP 2]

Jeff,There's about 295nm between DOTTY and 5248N so it's possible that there would have been a few degrees of difference between RC's calculated track between those waypoints and that of your FMC but certainly not the 180 degrees (275 - 095) that you mention in your original post.No, the only reason you'd get a track difference of 180 degrees between DOTTY and 5248N is if you failed to progress DOTTY to RC's satisfaction. Try flying the plan again and see if you can replicate the problem. If you're told you're 180 degrees of track again, check the waypoint RC is navigating to (top line of the advdisp window) against the current one in your FMC. That should you give you the answer to the problem.Pete

[clements 4]

>Jeff,>Bryan is correct - you missed a checkpoint (waypoint). The big>clue is the 180 degree turn RC wants you to do to reach it.>Remember, you're required to pass within 2nm in the departure>phase and within 5nm in the en-route phase to be credited with>a checkpoint.I think you can also get turned around when you're not climbing or descending at a rate that ATC likes. >The solution if this happens in the en-route phase of your>flight is to select the "Dir Chkpoint" item from the advdisp>menu (you'll find it on page 2 by pressing the "next" key) and>request a direct route to whichever waypoint your FMC/GPS etc.>thinks is next. Problem solved.Your "Dir Chkpoint? suggestion is a great one. I use it to get back on-course if ATC turns me around. Bob

[PeteP 2]

I think you can also get turned around when you're not climbing or descending at a rate that ATC likesHi Bob,I'm glad you're finding the "Dir Chkpt" function useful for missed waypoints. I don't know of any routine in RC that turns you around because of a poor climb rate - although it that does happen occasionally in real life. What you're probably thinking of is when the RC controller turns you away from approach's airspace if you've descended too slowly to make your crossing restriction. In this case, it's always a specific heading 90 degrees away from your original heading and is only applied until you reach the level specified in your descent clearance.BestPete

[Guest jeffg]

I will refly the route tomorrow and see what happens. Jeff