Hi guys.

 

Does anyone know how airliner diversions are handled in reality?

 

On a diversion you're obviously not going to have a planned route in the FMC for the plane to follow, so how does it work?

 

You can do what you like in FSX, e.g. just enter a new destination and approach then select direct-to the initial approach fix, but that's not necessarily how it should be done.

 

Many thanks.

The first thing you do is call DISPATCH, and get them working on it for you !!

If you are going to divert, it's going to get expensive.

The best solution is the one that is going to cost the least, and many complex criteria goes into that calculation.

 

 

http://www.nycaviati...t/#.UHMRFK6wV7c

 

is interesting reading on the subject

So here is what happens for us. Approaching the destination as we get Wx we see that we aren't going to land yet. We will generally hold (if able) and while in holding we will start looking for alternates (unless we were already give one). We check Wx at those places and see where the best place might be. Some of the considerations that go into it are weather, airport approaches, along with whether our airline serves that station (we never divert somewhere that our airline doesn't serve). Usually dispatch has a place they would like to see us go. Anyway, after we look at Wx and determine what is a good alternate, we ACARS our dispatch and give them out intentions and fuel load. They will run the numbers if needed because it is a new alternate or a different one. Then once they give the ok, we advise ATC of our intentions and they usually give us vectors to the airport. On our way we do our normal landing preparations in addition to informing the people in the back and letting our operations on the ground know (dispatch will call them before that and let them know we are coming and what our plane will be). Once on the ground we either fuel up and leave right away or deplane the passengers if needed and wait it out. That is it in a nutshell.

Similar to the above but we have no ACARS so we are our own dispatch. Only had one diversion so far, so we took a lot of extra fuel and held for 20 minutes at our planned destination with absolutely zero improvement in that time so we decided to go to the alternate having checked the weather both before the flight and whilst in the hold. ATC gave us direct to a fix near the ILS for that airport and then vectors later on for a CAT 2 landing. Not ideal for our passengers, but we anticipated the threat and made good decisions. Landed at the alternate, our passengers got off and we waited 4 hours for the return passengers to be bussed up to us, and then flew back to our original departure airport. Not a big deal really but part of airline life!

 

Henry Lidster

The best solution is the one that is going to cost the least, and many complex criteria goes into that calculation.

 

Sometimes the cheapest option isn't the best. I might want to go to an airport that my airline doesn't serve or one that is in the clear. Sometimes dispatch doesn't have the answer. Think Alaska 261.

 

This is where your 4th stripe comes in to play.

Thanks very much for the responses guys, very informative!

Sometimes the cheapest option isn't the best. I might want to go to an airport that my airline doesn't serve or one that is in the clear. Sometimes dispatch doesn't have the answer. Think Alaska 261.

 

If you consider all the costs, then cheapest is best. Of course what is more expensive flying-wise, might end up cheaper in the end

 

(for example, consider flight ANC-SEA. 80% of people continue to PDX for some reason. What will be cheaper, divert to BFI, bus all those people to SEA and fly or bus them to PDX, or divert to PDX and only bus the 20% elsewhere? Might very well be the second option.)

If its not an dire emergency then I fly to the nearest airport that the airline serves but if its a bad emergency then I land at the nearest suitable airport. I fly to the planned alternate if the wx is bad but usually perform autolands if its just the visibility that's causing the issue.

If you consider all the costs, then cheapest is best.

I'd say if cost is your only consideration, then cheapest is best. That's for the bean counters on the ground in comfy chairs to decide.

 

If you've got fuel and time, go for it - spend it to find a good solution.

 

If not, then you've got to choose a safe option, not a cheap one. They may or may not be the same thing.

If not, then you've got to choose a safe option, not a cheap one. They may or may not be the same thing.

 

I would say that anything that is not safe is not cheap either, especially in the long run.

 

In general, I think we both agree in principle, but as a business major, I am taught to consider costs beyond what most people see, and in that might be a reason why I see "cheap" where you do not.

Hello, This post does not affect me as I dont use ATC however, It is one of the best posts in recent weeks and the replies were very informative. I detected that real world pilots were involved in the replies (maybe not) which makes FS more realistic. Thanks a lot. Richard Welsh.

Sometimes the cheapest option isn't the best. I might want to go to an airport that my airline doesn't serve or one that is in the clear. Sometimes dispatch doesn't have the answer. Think Alaska 261.

 

This is where your 4th stripe comes in to play.

 

Ultimately you're right, but let's change "sometimes" to "rarely."

 

There are very few true emergencies on an airliner. The plane being on fire, all engines spooling down, or smoke are real emergencies. The intended destination being below minimums for landing (or whatever the reason to divert might be) isn't an emergency, and so the dispatcher must be consulted. In the US, the dispatch and PIC share responsibility for the safety of the flight. Which means the dispatcher should agree with the diversion decision. Also, the dispatcher can get the ball rolling at the diversion field to ensure that fuel, and passenger handling are in place for your arrival. Very rarely do diversions just suddenly become necessary to the degree that there isn't time to discuss it with dispatch. In every flight that I've had to divert, or that there's been a possibility of needing to divert, I'd say there was about a 10 minute window during which possible courses of action could be thought out before really needing to make a decision.

 

If there's a true emergency, and the plane needs to be on the ground immediately then no one will fault a crew for proceeding to the nearest field and putting the plane on the ground. For every other diversion, you can't just go where ever you want to go. US carriers each have their own table of approved airports for operations, and you have to go to one of those airports. For all the non-emergency diversions, a long list of variables are considered. Available fuel is definitely high on the list, but generally speaking it's the cost of receiving services at the possible diversion airports that is typically the determining factor. Airlines have contracts at each station that will determine the cost of the required services, along with alternate transportation if it becomes necessary. Also, if numerous aircraft are diverting, dispatchers have to keep track of total diversions to each field so that the ground services don't become too overwelmed and so there's enough room to even park all the aircraft.

 

Just because the intended destination's weather drops doesn't mean you're going to go looking for the field with the best weather conditions, beyond ensuring they're above minimums for arrivals and departures, the weather is a low concern compared to costs.

Reminds me of 9/11 when USA airspace was shut down, and alot if the us bound international flights got diverted to Canada.