Different Altitude than Filed

Salkadi

Well-Known Member
I'm a dispatcher for a regional airline. We do regular flights between SLC-SNA. A captain on one of my flights asked why he was filed at FL310 for the west bound flight, he also said that was the third that had happened. I checked the flight strip that was sent to ATC it had FL340 on it. Apparently, the discrepancy came in from ATC, they had changed the departure from the flight plan due to runway configuration in SLC, but why the altitude change?

Also, to add, apparently this was with clearance delivery, the controller asked him what flight level he wanted after reading the FL310.
 

maksvell

Well-Known Member
it could be center leveled off the guy at FL310 for crossing traffic and then didnt bother to give another clerance for a filed altitude
 

Vector4Food

This job would be easier without all the airplanes
^^ what he said.

Most likely anyway, regional pilots in my experience are a bit like cold war era Russian pilots, they don't question ATC instructions.

Edit: I'm not complaining either...
 

FM_Weasel

Well-Known Member
Centers will change a departure's requested altitude while they're on the ground for traffic?

The OP's question seems to pertain to filed altitude, not an altitude assigned during flight for traffic.
 

Salkadi

Well-Known Member
Centers will change a departure's requested altitude while they're on the ground for traffic?

The OP's question seems to pertain to filed altitude, not an altitude assigned during flight for traffic.
That is correct. The flight was still on the ground when this issue came up.
 

s60

Well-Known Member
There are a number of reasons Center might change your filed altitude. It could be for that destination, that's the highest possible alt to get approved. It could be for that route, that's the highest we can approve, and the other route where you can go higher will add so much time to your flight the controller didn't think it was worth asking which you wanted. It could have been an accident - I've done that a couple times, but good controllers will ask what altitude you want after doing that if they don't know what the previous request was, at least once you are on with the Center sector who changed the route in the first place. Or it could be something I'm not thinking of right now. It rarely hurts to just ask the controller, most of us will gladly explain why we did it, and even offer a different altitude if we can. I don't know of anyone who would do that without a reason/accidentally.

We do occasionally see airline flight plans that pop into the system filed wrong altitude for direction, that are everyday flights usually filed correctly. That usually gets a "silly dispatch" type comment from us behind the scene, then we just ask the pilot what altitude he wants when we talk to him.
 

ppragman

Direct BATTY
^^ what he said.

Most likely anyway, regional pilots in my experience are a bit like cold war era Russian pilots, they don't question ATC instructions.

Edit: I'm not complaining either...
I find this...alarming. I'm kind of the opposite though, maybe that's a bad thing, but I always question stuff like that - mainly to make sure I didn't screw up and write the wrong thing down. Also, I'm always asking for direct, I'm sure it bothers some of the controllers, but "No I want to go direct, is there any chance for that? When I get close I'll cancel, the weather's good there, but I want to go direct." I've been known to ask whether or not I've been cleared to land on a fairly regular basis - sometimes it's just not clear, or there's a little doubt on my end whether they guy cleared me on this trip, or on one of the other 4 to 8 trips I made that day. I ask questions or for direct all the time, I figure it can't hurt, and if it keeps me from bending metal, getting violated, or fired then it doesn't hurt to ask - especially when the cockpit is busy and there's a lot going on. But that's just me.
 

FM_Weasel

Well-Known Member
At the terminal facilities I've worked at, center doesn't get involved with our clearances until after the aircraft departs. If a requested altitude on a flight plan is changed, it's because we did it ourselves. Probably to make it comply with agreements we have with adjacent facilities (centers included)
 

s60

Well-Known Member
At the terminal facilities I've worked at, center doesn't get involved with our clearances until after the aircraft departs. If a requested altitude on a flight plan is changed, it's because we did it ourselves. Probably to make it comply with agreements we have with adjacent facilities (centers included)
That's interesting! Does center fix routes, or do you? At my center, we have to check all the routes that will enter our airspace, and either put any change in the computer or, if it's within 15 minutes of the p-time, call the tower/approach that will give the clearance so they know a revision's coming. As for altitudes, each controller does it differently. Some leave the requested in until they are talking to the plane then work it out with the pilot, others change it on the ground then tell the pilot when they check in, and others change it on the ground and don't say a word to the pilot unless questioned.
 

FM_Weasel

Well-Known Member
I'm a dispatcher for a regional airline.A captain on one of my flights asked why he was filed at FL310 for the west bound flight, he also said that was the third that had happened. I checked the flight strip that was sent to ATC it had FL340 on it.
After re-reading this situation, this was almost certainly to fulfill a requirement spelled out in a Letter of Agreement between SLC Center (or Approach) and SLC tower. Clearance delivery is probably required to make sure flights going out that way are expecting odd altitudes. After departure, the radar controllers responsible for actually dealing with the flight can make the determination (either themselves or via verbal coordination with the facility requiring the altitude) to change the cruising altitude back to whatever the pilot wanted.

That's interesting! Does center fix routes, or do you?
We do. We need to make sure routes comply with Letters of Agreement, same with the altitudes requested. It's all spelled out in writing, though some of it may be done automatically by our flight data computer. Say we get the following route for EGF3263 and it is:
"KACT KDFW" (otherwise known as "direct")

When we get the flight plan strip printout, it will look like this:

+JEN JEN9+
KACT KDFW

And we'll clear that flight "via direct Glen Rose, Glen Rose 9 arrival." The altitudes don't get changed automatically like that, but since we have to memorize all LoAs with adjacent facilities, we'll know when an altitude needs to be amended. At that point, it becomes like you say here:

Some leave the requested in until they are talking to the plane then work it out with the pilot, others change it on the ground then tell the pilot when they check in, and others change it on the ground and don't say a word to the pilot unless questioned.
Different techniques, for different folks. I always prefer to change it immediately to comply with our agreements, so if the next controller sitting down doesn't notice it, we don't have a goof. After issuing the revised altitude, I expect the pilot to speak up if they have an issue with the new altitude (it's usually only different by 1,000 ft or so).

At my center, we have to check all the routes that will enter our airspace, and either put any change in the computer or, if it's within 15 minutes of the p-time, call the tower/approach that will give the clearance so they know a revision's coming.
This sounds similar to what we do, but it mostly comes through the flight data computer automatically. At towers without a flight data computer, I could see the need for those procedures. If we don't get an automatic amendment to make the route "legal" we're expected to know to make the proper amendment ourselves, because we have the agreements memorized. Since the LoAs cover how aircraft are allowed to exit our airspace, it really doesn't matter how far in advance the amendment occurs. It mostly all gets done well before the aircraft even picks up their clearance, much less departs.

Interestingly, out flight data computer only "plus routes" (places routing between plus mark symbols) for portions of the route into the next facility or two's airspace. Beyond that it usually goes "direct" to the destination airport. Since everything is connected, I don't know why the routing isn't just calculated out as far as possible, but I expect pilots get caught off guard when the departure tower clears them "direct," or with a small route change THEN direct, and shortly after departure Center completely re-routes them.
 

Vector4Food

This job would be easier without all the airplanes
Ppragman, ive tried to reply to your post but my iPhone keeps loosing my paragraphs, I'll clarify a bit in the morning.
 
Top