# Flight Tracking Altitudes **URL:** \ **Category:** General\ **Created:** [July 9, 2006, 4:03pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709 "2006-07-09T16:03:58Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 9, 2006, 4:03pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/1 "2006-07-09T16:03:58Z")
What criteria is used to indicate the altitude information? It appears that the arrows indicate climbing and descending, but I don’t understand how an assigned altitude is depicted. Occasionally a lower altitude will appear in the sequence with a down arrow and seems to remain until the aircraft actually starts a descent. ---
**Author:** ![dbaker](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/dbaker/32/97166_2.png) [@dbaker](https://discussions.flightaware.com/u/dbaker)\ **Post date:** [July 9, 2006, 4:11pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/2 "2006-07-09T16:11:28Z")
Can you paste a link to an example so I can take a look at what you’re describing? ---
**Author:** ![mduell](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/mduell/32/115680_2.png) [@mduell](https://discussions.flightaware.com/u/mduell)\ **Post date:** [July 9, 2006, 4:16pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/3 "2006-07-09T16:16:33Z")
This is a bug in our feed from the FAA. When an aircraft is assigned a lower altitude, a radar site (usually not the one currently tracking the plane) will claim the aircraft is immediately at that altitude. The normal descent then comes from the radar site actually tracking the aircraft. ---
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 10, 2006, 1:19am UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/4 "2006-07-10T01:19:31Z")
In this example ([flightaware.com/live/flight/N418 … U/tracklog](http://flightaware.com/live/flight/N418GJ/history/20060706/2029Z/KLZU/KHOU/tracklog)), at 16:51 the altitude column indicates 40000; at 16:52 it indicates 37900 with a down arrow; at 16:53 it indicates 35000 with a down arrow; at 16:54 it indicates 40000 with an up arrow. In another example ([flightaware.com/live/flight/COA1 … O/tracklog](http://flightaware.com/live/flight/COA1086/history/20060706/2128Z/KIAH/KMCO/tracklog)), at 17:46 the aircraft c0lumn indicates 35000; at 17:47 it indicates 15000 with a down arrow that remains until 17:55 when it changes to 31800 with an up arrow before changing to 28200 with a down arrow at 17:56. I understand from the last post how the second example exists, but it doesn’t explain the first example. Thanks! ---
**Author:** ![mduell](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/mduell/32/115680_2.png) [@mduell](https://discussions.flightaware.com/u/mduell)\ **Post date:** [July 10, 2006, 2:01am UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/5 "2006-07-10T02:01:10Z")
Your first example is a slightly different permutation of the same bug. Another radar site is claiming intermittently that the aircraft is at its previously assigned altitude of FL400 during the descent. We plan to add some code to detect these bogus altitude reports (as we recently did for the bogus position reports off the coast of Africac) in the future. ---
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 10, 2006, 3:16am UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/6 "2006-07-10T03:16:51Z")
FlightAware is a great website for general information. An airline pilot recently told me about hearing communications related to an inflight emergency. When the N Number was researched, the flight track data verified that such an event had occurred. Keep up the good work. ---
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 10, 2006, 11:19am UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/7 "2006-07-10T11:19:02Z")
Which radar systems are available to FlightAware? I see that most arrival tracking terminates short of the terminal area. ---
**Author:** ![pika1000](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/pika1000/32/124076_2.png) [@pika1000](https://discussions.flightaware.com/u/pika1000)\ **Post date:** [July 10, 2006, 12:25pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/8 "2006-07-10T12:25:05Z")
> [@cboneill](#): > > Which radar systems are available to FlightAware? > > I see that most arrival tracking terminates short of the terminal area. In my experiences, a lot of pilots (private, not commercial) will cancel their IFR plan when they get close to the airport. If you look at the history of a friend of mine (Take out all flights to MYAT, even though where they end, is where he typically cancels IFR) N86RL, you will see that the vast majority of his flight tracks end before he gets to his destination. When I fly with my FIL, and on the occasion we do file IFR, we typically cancel before we get to our destination (usually RVS or 2V1). When we are heading to 2V1, typically it is automatically canceled by Denver Center because it is in a “void” for radar once you get below FL180, which we typically are by that point. Either way, there are tons of different possibilities for the answer to this. ---
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 10, 2006, 5:58pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/9 "2006-07-10T17:58:57Z")
I don’t think that an air carrier cencels IFR prior to landing. There’s got to be another explanation. ---
**Author:** ![dbaker](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/dbaker/32/97166_2.png) [@dbaker](https://discussions.flightaware.com/u/dbaker)\ **Post date:** [July 10, 2006, 6:01pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/10 "2006-07-10T18:01:19Z")
Can you link to an example of an airline flight where the line ends prematurely? ---
**Author:** ![pika1000](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/pika1000/32/124076_2.png) [@pika1000](https://discussions.flightaware.com/u/pika1000)\ **Post date:** [July 10, 2006, 6:07pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/11 "2006-07-10T18:07:34Z")
> [@cboneill](#): > > I don’t think that an air carrier cencels IFR prior to landing. There’s got to be another explanation. In that case, I give you the all encompassing answer of “Because they can” ---
**Author:** ![pika1000](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/pika1000/32/124076_2.png) [@pika1000](https://discussions.flightaware.com/u/pika1000)\ **Post date:** [July 10, 2006, 6:07pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/12 "2006-07-10T18:07:56Z")
> [@cboneill](#): > > I don’t think that an air carrier cencels IFR prior to landing. There’s got to be another explanation. In that case, I give you the all encompassing answer of “Because they can” ---
**Author:** ![damiross](https://avatars.discourse-cdn.com/v4/letter/d/b9bd4f/32.png) [@damiross](https://discussions.flightaware.com/u/damiross)\ **Post date:** [July 10, 2006, 6:22pm UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/13 "2006-07-10T18:22:27Z")
> [@cboneill](#): > > I don’t think that an air carrier cencels IFR prior to landing. There’s got to be another explanation. An air carrier can cancel IFR and fly visual into the airport. ---
**Author:** ![cboneill](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@cboneill](https://discussions.flightaware.com/u/cboneill)\ **Post date:** [July 11, 2006, 2:33am UTC](https://discussions.flightaware.com/t/flight-tracking-altitudes/1709/14 "2006-07-11T02:33:22Z")
Okay, so I used the term Air Carrier incorrectly. Air Taxi operators are Air Carriers. Nevertheless, it is unusual for a Part 121 carrier to cancel IFR before landing. The number of terminated flight tracks depicted in FlightAware certainly aren’t explained by cancellation of IFR.