When are you obligated to go to your filed alternate

[luvflyin]

Never. If you divert during a lost comm scenario they will look for you there but I wouldn’t feel obligated to be there when they came looking.

Yeah. There may be a ‘valid’ reason to go somewhere else. Besides finding you after you land, there is the issue of separating you from other airplanes while you are flying to there. If the weather is not suitable for landing at the destination airport then the ‘anticipated pilot action’ would be to go to the alternate.

From the ATC rulebook:
1. When an IFR aircraft experiences two-way radio communications failure, air traffic control is based on anticipated pilot actions...

Now a lot of the country is under Radar coverage and they just use that to keep everyone else out of the way while they watch you do your thing. But sometimes there isn’t Radar and they got to do things based on your anticipated actions. Even with Radar your transponder may go with your radios. Tracking a primary target can be iffy sometimes depending on the Radar system and weather.

Going to your alternate, buying some gas, waiting out the weather and then being on your way is different than going to your alternate and wondering how long it’s going to take to get the airplane fixed. Deciding to go some airport other than your alternate because Aunt Sally lives there and will let me crash at her place until the airplane gets fixed is probably not going to fly as a ‘valid’ reason. If you caused some incident by doing an ‘unanticipated’ pilot action you may get to meet some official type people and talk to them about it. All of this of course is notwithstanding that if you get VFR, get the airplane out of the air and on the ground as soon as practical

 

[Palmpilot]

...Your flight plan provides ATC with the expectation that you'll go to the filed alternate...

Many controllers have said that they don't expect you to go to your filed alternate, and that it is normally not even sent to ATC.

 

[Tarheelpilot]

Yeah. There may be a ‘valid’ reason to go somewhere else. Besides finding you after you land, there is the issue of separating you from other airplanes while you are flying to there. If the weather is not suitable for landing at the destination airport then the ‘anticipated pilot action’ would be to go to the alternate.

From the ATC rulebook:
1. When an IFR aircraft experiences two-way radio communications failure, air traffic control is based on anticipated pilot actions...

Now a lot of the country is under Radar coverage and they just use that to keep everyone else out of the way while they watch you do your thing. But sometimes there isn’t Radar and they got to do things based on your anticipated actions. Even with Radar your transponder may go with your radios. Tracking a primary target can be iffy sometimes depending on the Radar system and weather.

Going to your alternate, buying some gas, waiting out the weather and then being on your way is different than going to your alternate and wondering how long it’s going to take to get the airplane fixed. Deciding to go some airport other than your alternate because Aunt Sally lives there and will let me crash at her place until the airplane gets fixed is probably not going to fly as a ‘valid’ reason. If you caused some incident by doing an ‘unanticipated’ pilot action you may get to meet some official type people and talk to them about it. All of this of course is notwithstanding that if you get VFR, get the airplane out of the air and on the ground as soon as practical

Hmm

Well I assumed it was rather obvious there should be a “real” reason for not going to the planned alternate but perhaps that was an unrealistic assumption that I wasn’t addressing a group of dummies. Thanks for backing me up and clearly spelling it out for the group.

 

[luvflyin]

Hmm

Well I assumed it was rather obvious there should be a “real” reason for not going to the planned alternate but perhaps that was an unrealistic assumption that I wasn’t addressing a group of dummies. Thanks for backing me up and clearly spelling it out for the group.

Gotcha. The main reason I replied to your post was to emphasize that there is more to it than finding you after landing. What you and other airplanes in the sky are doing while getting there is very important.

 

[Tarheelpilot]

Gotcha. The main reason I replied to your post was to emphasize that there is more to it than finding you after landing. What you and other airplanes in the sky are doing while getting there is very important.

Yeah. It’s mainly about not hitting other traffic. Finding you is secondary. You were right to expand on what I said. I left out a lot of detail due to the assumptions I made.

 

[Palmpilot]

..."If the failure occurs in IFR conditions, or if paragraph (b) of this section cannot be complied with, each pilot shall continue the flight according to the following:
<list of things>
...by the route filed in the flight plan."
And apparently they take that to include the filed alternate.

However, he did give the caveat that if your alternate is also below minimums and you are running low on fuel then you could and should invoke FAR 91.3 by declaring an emergency and go where you need to go.

But it sounds like in a lost comms situation you can't deviate from your filed alternate (assuming it's legally and safely flyable) simply because someplace else is better.

An alternate airport is not a route. It's not even part of the filed route, because it's not entered in the route field of the flight plan form. Furthermore, no space is provided to enter a route to your filed alternate. So based on the design of the form, I conclude that the "route filed" ends at the primary destination, and therefore the regulatory paragraph that references the "route filed" is no longer applicable after that point.

 

[Witmo]

Filing an alternate is an exercise in weather checking and fuel management. Suppose I choose an alternate that is well away from my destination where the weather is great (at the alternate, not the primary). I load up on fuel for worst case. I arrive at destination and cannot land. Before I start heading over to the alternate I findthat the weather at airfield much closer would allow me to land all that much closer/sooner to my intended destination. Does anyone really think ATC would rather I flog around in the clag clogging up the system comm out for any longer than I possibly have to? Does anyone think they sanitize airspace procedurally for an aircraft they can't see on radar on the expectation that he's on his way to a filed alternate? There is no legal requirement that forces you to go to the filed alternate if there is a better alternative.

 

[Dave S.]

You are never required to actually go to your filed alternate in the case that you can not land at the destination airport. You only must file for the alternate if require due to forecasted weather +/- 1 hour of eta...but you are not required to actually go there. You could go to a completely different airport if desired.

tex

 

[John Collins]

You are never required to actually go to your filed alternate in the case that you can not land at the destination airport. You only must file for the alternate if require due to forecasted weather +/- 1 hour of eta...but you are not required to actually go there. You could go to a completely different airport if desired.

Absolutely agree.

There was a fatal accident where a pilot ran out of gas after attempting an approach due to low visibility, widespread fog. He flew on to his alternate that had also deteriorated weather. The route was west bound along the Gulf of Mexico coastline into Texas, where both his destination and alternate were located. The pilot had received updated reports that the weather had deteriorated. For most of his route, VFR weather was only a few miles to the north, but the pilot continued on knowing the weather had deteriorated. Had he merely diverted to a VFR weather airport, he would have survived. I wonder if he was one of those who thought he had a legal obligation to go to his alternate. Sad.

 

[kgruber]

When we flew every day for a department store in the west, we virtually ALWAYS used Lewiston, Idaho for the alternate. Never went there, but it always had alt minimums.