Diversion planning and execution

[Will]

True story: back when we were CFIs looking to build hours, my buddy Dave got a gig ferrying a Beechcraft Duke from somewhere far away to somewhere nearby. That night, we get a phone call - it's Dave, can we please come pick him up tomorrow in a C-172, you see, the Duke had an engine failure and he made an emergency landing at a small airport in the middle of nowhere, and it's going to be a long time before the Duke can be flown out again.

So early the next day, we go get Dave. The airport he landed at is tiny but picturesque, the type of place you'd consider for a "$100 hamburger" jaunt. Or maybe even a more impressive outing, as the field had a tiny two-story motel on it, as well as Longhorn Larry's Steakhouse, "home of the Cattleman's Cut," supposedly the best beef in the American Southwest. There were a few light planes tied down to the tarmac, and then there was Dave's broken Duke, parked right in front of the restaurant.

As eager young pilots, hungry for stories of Avgas and adventure, we were very curious to hear what happened to Dave. Was the engine failure dramatic? What was it like to have an emergency on your first-ever flight in type? Did things get tense? Most importantly, how was it to flight-plan a diversion to an unfamiliar airfield while flying on one engine and all alone?

"Oh, the diversion was pretty easy," Dave said. "I just asked ATC for radar vectors to the nearest airport with a steakhouse and a motel on the field."

[IefCooreman]

Next week - Fire categories (unless someone beats me to it - feel free!)
Peter

PCN, then fire categories... oh boy... :-). I'll leave the hono(u)r of explaining this to you, but i'll try to write down a post on how it's ("supposed to be") done in our operations. This might take a while... grin... :-)

[IefCooreman]

So, the "planning" of a diversion...

To discuss how diversions are "organised" there are basically two questions:
1) Why?
2) Where?

To tackle the first question, one must know a little bit about the second. The "Where?"

Our company has sort of copied the ETOPS way of working on the European network. You have all the commercial airports in the world, a selection is made and verified by the offices on minimum requirements (runways, navigation, services, etc...). This generates the list of "adequate airports". For certain remote regions (Siberia, etc...), they will also have "emergency" airports as there are so limited amount of options, but the fact they are classified "emergency" says enough: don't go there unless you really need to (engine failure & depressurization cases).

What do they look at? PCN, fire fighting category, opening hours, performance, chart availability, briefing requirements,... and they will put it all in a long list which we always have on board including all briefings. The performance is kinda "worst-case" (hot day, etc), just to make sure, but it gives us a little clue of our maximum capabilities/limitations on a certain runway.

On the day of the flight dispatch takes the list, picks the minimum amount of required airports (yes, the absolute minimum...) and checks notams and weather. If ok, they are mentioned on the flightplan. One takeoff, enroute if required, one or two destination alternates depending on different factors.

Back to question (1): why?

Technical: technical means we can't continue to our destination. Even though we do have enroute alternates, we have almost absolute freedom. The alternates on the flightplan are nothing more than a legal cover. We look at the problem and make an analyses: what do we need? (long runway, no crosswind, good medical services, maintenance services,...) and then we look around us and look for it... and look at how we can get there (terrain, weather, fuel critical,...?). This is sometimes referred to as the "inside-outside" analyses. We will look at the list of adequate airports as a primary reference, unless we really really need to be on the ground asap (fire/smoke).

As mentioned before, there's a lot of communication but that communication comes after you've made up your mind on what you want/need (inside). Not before. Most extreme cases are medical where we won't rush at all (don't kill yourself trying to save the other), and fire/smoke, where we'll take anything that is longer than 1200m with an ILS. Performance checks become important here, we basically calculate the influence of the problem on our aircraft and check landing performance just to make sure we don't hit the approach lights on the other side of the runway. Overweight landings depend on the situation but there are checklists for that as well, so they don't really limit us. All these cases usually resolve into some kind of priority request where ATC is hopefully your friend. On the flightdeck, good CRM, prioritising, and task distribution are key in this whole process.

Non-technical diversion: weather at destination, operational reasons, airport closures,... Basically these diversions are "easy" up to a certain point as we try as much as possible to stick to what the company has asked us. We fly for clients, the client decides what he wants. He usually wants us to be on our destination and picks a first alternate really close. For our main client, this is all negociated beforehand. They decide on our minimum fuel (based on max payload). We have the liberty to add for weather or traffic of course, but only because we want to get the job done. Upon arrival we basically look at the time available, try to burn that fuel if we have to wait, and divert to the selected airport if time runs out.

The big difference here, and the big risk, is that there is no priority. In many of these cases, if one aircraft diverts, many are to follow, and for some odd reason all dispatch offices work with the same airports... There are days when low visibility is all around a region and you will see all these aircraft looking for one airport. The risk is that – despite the fact this airport is mentioned on your flightplan as a primary alternate, the airport itself has no obligation to accept you.

Again communication is key. If there are doubts on where to go, these are usually resolved preflight already in the crewroom where we will call dispatch and ask to confirm where they want us to show up in case destination is not an option. As there isn't really a decision process, it's better to keep ATC in the loop as soon as possible. They can contact our alternate airport and sometimes even "guarantee" you a slot at the alternate in case of.

Anyway, my 2 cents on diversions. Charter flights are a bit of a different discussion.

[Holger Wende]

  I feel a bit naive with my amateur questions after having read all the considerations and constraints.

Now I see, diversions are a really complex topic and the pure FMC work is only a tiny portion of the overall challenge.
Thanks to all for sharing your insights.

What is the extra challenge with charter flights? Tourists only, sometimes isolated islands, ...?

Regards, Holger

[cagarini]

Holger,

I am so so so with you :-)

Problem is, it's about pretty much every complex item discussed at these forums :-)
I feel so so dumb at times ....

When that hapens I go trying a loop or a barrel-roll in the 744, maybe a hammerhead... Or dive from FL 400 at near 90º to see what happens to the turbines...

[Britjet]

Guys - all this is nice to think about but not much of it is relevant to simulated ops like PSX.
It makes my head hurt, too -  so don't feel bad about it!
For most of us diversions were in any case a very rare event, and I doubt if many accomplished them without a few misdeeds. If I think of mine they all went wrong somewhere!
We'll try to get onto some more relevant methodology on this post soon.

Peter

[IefCooreman]

Sorry Britjet, I read your post on PCN and fire fighting and was thinking "oh that's part of it?" and that made me write my post.

Don't want to take it too far. The charter business, I'm referring to ad-hoc business. These one-off flight usually bring you to very specific airports, sometimes outside of what the airline is used to work with, and these are the real "story generators". When you leave the "network" environment, you become a DIY crew, which is the reason why we usually have loadmaster and engineer with us. Diversions are really "oh no" situations for these flights.

But if you divert in PS, and the airport is not in the FMC, or you don't have the approach in there... it's part of reality to :-). Back to PS!

[Britjet]

Sorry Britjet, I read your post on PCN and fire fighting and was thinking "oh that's part of it?" and that made me write my post.

Not at all! It was a very interesting post- I learned a lot!

Re the firefighting then..
The Fire Category is usually called the "RFFS (Sometimes called the RFF) Category". RFFS stands for "Rescue and Fire Services". It is found in much the same docs as PCN etc.
There will be a category for an airport, and also for an aircraft, and both can change depending on circumstance.
At an airport the RFFS refers in the main to how many fire trucks they have, and how much "squirt" they have.
In the case of the aircraft, it is a factor of size eg A320 - 6, A380 - 10.

The absolute minimum fire category for a pax version of the 747 is 4. But I would stress this is a minimum, in extremis..
The standard RFFS is 9 for the 747, but it can be reduced, for instance, if it is the subject of a NOTAM to 8, or even 7 if the NOTAM is temporary. Of course, in an absolute dire emergency - it is irrelevant.

At most major airports the RFFS is usually 10 but of course it will be lower elsewhere, and at any airport it might well be degraded (this would be in a NOTAM). Such NOTAMS will usually give the time(s) of the reduction, and quite often that they can be reinstated at, say, 1 hour's notice. (I have a vision of some overworked mechanic being asked to put the fire-truck back together as there is an emergency inbound, or maybe they just take one out of service for a few hours for the local fair, or to jet-wash the fire-chief's patio!).

Some computerised flight-planning software might take note of this sort of thing, but it would be a necessary check by the crew that all their required alternates had the necessary fire cover.

My head is spinning again..

Peter

[Holger Wende]

I am so so so with you :-)

Thanks, good to hear/read, I honestly feel better now

It makes my head hurt, too -  so don't feel bad about it!

I only feel bad about my limited time I can spend in this forum and my limited brain capacity to digest all the interesting details.
Most posts are really fascinating and the nice thing on a forum is, I can stop reading if I feel overloaded or if discussions get too technical 
But although I am an amateur flight enthusiast I enjoy reading about background information which just broaden my horizon. And it's really entertaining to realize how an apparently simple topic (to me) turns into such a complex matter 

I "played" with diversions a few times already:
E.g. I recall a flight from Dubai to Male and roughly half way out over the Indian ocean I had the spontaneous idea about what if I had to divert now? Where to go? Just as an experiment.
Searching for the next suitable airport(s) from my current position distracted me entirely from thinking about the Why of the diversion.

The past forum articles about diversions covered lots of the necessary considerations and I am sure my next diversion will be significantly more thought through.

Some aspects may not be not applicable to the simulator, ok, but I am just curious and want to learn how it works in real life.

Best regards, Holger

[Jeroen Hoppenbrouwers]

Just to add fuel to the fire: h'bout planning diversions while ascending to orbit? Or the slightly more challenging abort from orbit?

https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes


Hoppie

[Toga]

In my airline we use a decision making model known as T-DODAR to help standardise non normal events. The idea being we are able to use all available resources to mitigate errors and increases our chances of making the right decisions when we find ourselves outside of the comforts of routine. These days UK airlines are sh*t hot on CRM, TEM and DODAR. Every decision you make is being scrutinised and big brother is always watching.

Before you rush into your DODAR don't forget to FLY THE AIRCRAFT! ANC! See too many guys rushing straight into a DODAR meanwhile no one is flying the plane. Aviate, Navigate and communicate!

Below is for sim checks mainly but you get the jist. The DECIDE bit in real world could be anything!

You'd usually run through your DODAR once you're satisfied the a/c is secure and you've given yourself time to think. So perhaps ask for a hold someplace to give yourself a momentary pause in space.




Post TBC.

[Martin Baker]

I like that the cabin crew are referred to as NITS!

[Toga]

Martin, sadly NITS is a brief and the CC can give us one too! It stands for: Nature, Intention, Time, Specials. It's written down by the receiver then read back as a review.

[IefCooreman]

I presume this is more related to technical diversions, which to be honest, don't really happen that often. Modern aircraft are pretty sturdy. Long haul aircraft have triple redundancy on many levels. It is actually funny to read the company above prioritizes the "return". We prioritize the "continue". The background is our aircraft is sitting idle outstation during the day, and the company prefers us to continue to destination as long as there is no real reason to actually divert. During the day local maintenance can have a look, or own maintenance is flown in with spareparts to repair the issue while we sleep. A big difference between long haul and short haul as well.

The return or divert reasons are clearly defined by Boeing. Either the checklists tells you to, or you've lost all your redundancy (one electrical, one hydraulic, ...) or anything related to smoke/fire.

These days, if you mention the methodology you use, you can pretty much guess what company you fly for. If you want to know more about it, google FORDEC, DODAR, T-DODAR, DECIDE... There are many others, pretty much one for every company :-).

As opposed to firing abbreviations, I'll simply try to explain some keypoints we use in our company.

To make sure the flying part is the first priority, the initiating is always done by the PF (pilot flying). It is up to the PF to announce if he considers the aircraft situation to be "safe" enough to continue for a thorough identification of the problem. I call this the three P's (pitch – power – protect). It stabilizes the aircraft, makes sure all "flying steps" are taken and we protect ourselves in case we need to (oxygen). The PM is not allowed to initiate the sequence to force him to focus on the backup of the PF, so actually two persons are busy with the flying part.

When all checklists are run through the "roleplay" shifts from PF/PM to CPT/FO. The captain will usually hand controls to FO, makes a full technical analyses and the consequences for the flight if he deems there is time available.

Analyses boils down to "how severely is the aircraft/crew/pax downgraded?" That's the inside. I usually make a list of downgrades, the threats they create and how to avoid that threat. (roll problem > no crosswind/long final, antiskid problem > long dry runway, anti-ice problem > avoid clouds, no contaminations,...). The main idea here is not to find the perfect solution, but how to stay away from your new "weak points". Any technical problem can limit the performance of your aircraft, you simply outline what you are still capable of and what not.

Then you go "outside", seeks information and make a pro's/con's list on possible solutions. Outside can be anything you think is necessary. Terrain situation, weather situation, ATC info, airport info, company info,... Once the list pro/con solution list is made, the decision is taken as a crew. Next is then to inform all concerned parties (NITSA is indeed used everywhere), and the execution started.

At the end there is always a review process as it's a dynamic world and things you need might not always be available.

This work method can actually go a long way. There was a time when ISIS was growing we were all overflying Iraq, but we knew we would never ever wanted to divert to that country. Even with cabin depressurization we knew we would never go below FL250 until outside of that airspace.

Anyway, enjoy the diversions :-).

[localiser]

Re Pitch power protect.... some guys read out the FMAs to cover the AFDS modes are what they should be.

The point is it's easy to get distracted. I think Peter illustrated this idea of keeping an eye on what the flight path is doing in a really good way in his video 34 "Non Normal Procedures 3: human factors" at 01:10. Let it play for about 20 seconds...

I interviewed for a freight company a number of years ago and was interested to learn that they did not want you to divert for weather. They absolutely wanted you to take as much fuel as necessary to be able to wait it out for as long as possible because they wanted the packages to arrive at destination, not at an alternate 100nm away. Makes sense I suppose. I didn't take that job in the end but it was tempting for a minute just for the fuel policy!

[IefCooreman]

They absolutely wanted you to take as much fuel as necessary to be able to wait it out for as long as possible because they wanted the packages to arrive at destination, not at an alternate 100nm away. Makes sense I suppose. I didn't take that job in the end but it was tempting for a minute just for the fuel policy!

That sounds very familiar, though I usually tell people "don't hope too much, as you might get it". The day you spend 1hrs45 at 7:00am in a holding above a closed airport and dispatch tells you "it's fun watching you on flightradar..."

Times are a changing though...