MAYDAY during diversion
 

So since the original thread was closed, I will have to ask my question here. I did not mention any company names so I hope this will not be closed as well.

Can someone explain this to me?

Obviously military aviation as I am used to, is different from commercial aviation, in respect to purpose, rules and regulation. However, the built in safety margin and more specifically the reason for it to be in place, should in my opinion be the same. For us in the military, any diversion is a planned event, and a planned event will never require a MAYDAY call. We always carry extra fuel to enable us to divert. If weather dictates that we carry enough fuel so as to be able to divert in case we can’t land at the planned destination, we do exactly that. If its VMC conditions, we still have a requirement to carry enough fuel, so that we can divert to the nearest suitable airfield, in case the destination runway closes for whatever reason, just before we land (i.e. the plane in front of me crashes on landing). Only situation I can think of that will require a MAYDAY is if the weather changes unexpectedly (below landing minima) at both the destination and the alternate, and we now have to fly to an other airfield which will result in landing with less then minimum fuel.

So having multiple aircraft from the same company, declare MAYDAY during diversion, for any other reason then unexpected worsening weather, at both destination and alternate, just sound to me like pure planning or inadequate rules/regulation/procedures. Reminds me of a situation with a carrier that had multiple diversions with MAYDAY and low fuel, during a very short duration of time, in Spain some years ago...

Or is there just a big difference between our two worlds of aviation?

Do we know they declared a mayday or did they just set 7700. They might have declared pans or minimum fuel and ATC asked them to do this. Genuine question, I don’t know.

Of course it would not be normal but the system worked and everyone landed safely.

Regardless of a MAYDAY or 7700, the question still remains: Is a diversion a planned event or is it an emergency?

F16GUY
 

I’m military through and through and if I had to divert for fuel (I have a couple of times) I would declare a PAN as a matter of course.

The reason is that, upon reaching my diversion airfield, I would then be out of options and would need landing priority. This assumes that at the start of my diversion I was at my minima (I was when I did it for real).

When you reach your planned alternate you do not carry enough fuel for another alternate so it is your last chance saloon.

The question of PAN vs MAYDAY may carry a personal (or company SOP) element to it. In my mind (without giving it too much thought) it would depend on weather and traffic. If it is a VFR transit to the alternate and light traffic a PAN would suffice. If the situation was making me twitch then a MAYDAY may be required.

BV

A diversion doesn’t need to be an emergency. In the last two years I’ve diverted twice, one of which was under a pan. Also a diversion to your nominated alternate should ALWAYS be planned. Obviously they didn’t want to divert but given the situation presented, opted for plan B and did so safely. London ATC will then ask the aircraft their endurance and prioritise them accordingly. If the level of priority given is incompatible with their fuel state then they will first declare ‘minimum fuel’ and then potentially a pan or a mayday. The controller might ask them to set 7700 as it is a conspicuity code that will enable the other controllers of lower, upper or adjacent sectors to see them or see them coming.

Why would you have to divert for fuel? Fuel leak? Underflown Bingo fuel? That sounds to me like a different and unplanned situation obviously requiring some kind of urgency. The question is regarding planned events.

That makes sense for a single aircraft. But I think that when multiple aircraft from the same company are involved, something just doesn't add up.

The flight plan will include a few different parts to the fuel plan. The taxi fuel, the trip fuel, the alternate fuel and the final reserve fuel. In addition to those there is the contingency fuel. Most airlines use statistical contingency fuel (might be called something else) and it gives the crew an idea of how much extra fuel is routinely used on a route from A>B (an average of hundreds of flights to keep it simple). On a thursday in March, this will probably be a low figure, on a saturday in August, it will be a high figure. It should give the crew a decent starting point for thier fuel decision and encourages them not to take less as obviously the airline want the flight to reach the destination.

Crew will take extra fuel if the weather looks bad (today it didn't) or there are ATC delays (such as strikes, equipment failures etc), or they'd prefer an extra comfort margin for whatever reason. Maybe the captain is new and wants a better margin for another 5 mins of thinking time, but they don't just fill the tanks. The two aircraft that ended up diverting came from performance limited airfields (short runway, lots of hills etc - Look up Innsbruck for pretty pictures) so they can't just put on an endless supply of fuel. They do have other options, but business sense would dictacte that rather than offload passengers on a day with decent weather, on a quiet day of the week at a quiet time of year.

Don't forget that easyjet are BY FAR the largest operator into this airfield and therefore any issues (a sudden closure of the runway) will far more likely hurt them than another operator.

Don’t forget you have to get acceptance from the diversion airfield before you commence diversion.
What if your original destination is unavailable and you’ve held for 10 minutes waiting for the diversion airfield to accept you? Do you carry on holding? How long for?
Once you suspect you may land with less than 30 minutes fuel you must declare a Mayday and you can then divert with priority.(Mayday not Pan)

I imagine in the military, if you wish to divert you make the call and go immediately but in the commercial world a busy airfield might not have the capacity (or handling) to accept you.

The fact that it was the same airline may be down to the fact they are the largest operator there, no other reason and certainly not anything more sinister or foolhardy.

This is a good point. During storm Dennis or Kiara (cant remember) I heard a Vueling on the radio. They did 2 windshear go arounds and then requested a divert to MAN (150nm away). ATC didn't tell them their diversion was accepted for approx 20 mins and left them painting lines in the sky for that time in a poor position. Still south of LGW they headed north and then declared a Mayday and landed in LHR. You don't automatically get your nominated alternate as the UK is very capacity limited. On a nice day with decent weather, that shouldn't be a problem. Worst comes to worst, you declare minimum fuel, then a pan, then a mayday as required to get what YOU want. It's ATC are essentially triaging flights.

In the commercial world, we don't routinely carry additional fuel "just in case". It is entirely possible to have planned a flight perfectly adequately from a fuel point of view, arrive at your destination with your contingency, alternate and final reserve fuel intact, and through an unforeseen set of circumstances end up in a situation where you will land with less than final reserve fuel (30 minutes, or approximately 1200KG on an A320CEO). If you know that you will land with less than final reserve fuel, a MAYDAY must be declared.

I can't comment on the military SOP in such a situation, but a PAN for fuel is no longer correct phraseology in the UK.

I dont know about the EZY flights in subject, but sometimes we do fly with a RCF (Reduced Contingency Fuel) approved Flight Plan and a declared Decision Point (DP) where we do check our fuel levels and decide whether to divert to the agreed ALT or not based on the Flight Plan, thats a normal procedure that doesnt require any MAYDAY or PAN.

No difference. If you expect to land below Final Reserve Fuel (30 mins at 1500’) it’s black and white in the CAP. Mayday. If any further delay could lead to you landing below reserve fuel, it’s Minimum fuel.

big difference in civilian aviation I suppose is you can commit to destination once certain requirements are met. Never did that in the military, done it a few times as a civvie.

Especially if a busy airport like LGW has some issue affecting the landing rate, you will get a lot of diversions fast and those diversion airports and their ATC will become saturated equally fast as well. There is no doubt that ATC in the south of the UK is absolutely top notch, but even they are human beings and a lot of diversions do require a lot of extra work.

Considering the airline in question has something like 65 to 70 aircraft based in LGW, even a short problem will invariably involve quite a few aircraft. If it was not anything you can plan for, they probably did not take extra fuel to account for something like that.

According to the rules there is basically two levels of low fuel warning from an aircraft to ATC: after having committed to land at a certain airport you may end up with less than final reserve fuel in case of any change to routing or clearance, it is "low fuel", that is not an emergency and the aircraft in question will not get preferential treatment. Well, it might, but there is automatism there. The next level is, if it is certain that you will land with less than final reserve fuel, it will go directly to "MAYDAY Fuel". The difference between low fuel and mayday fuel is surprisingly small.

Standard fuel planning does not account for any holding at the destination, or delay vectors while ATC sorts out a diversion and so on. It is departure to destination including approach and missed approach, diversion to alternate, and then 30 minutes of holding (final reserve). On top there is of course fuel for taxi out and contingency, but that can be as low as 5 minutes and can be used at any time after off blocks for any reason, so it might not be available at the destination.

I had it myself, waiting 15+ minutes until ATC had sorted out a diversion, it can happen. And the fuel used during that time does not have to be planned for, so it can dip into final reserve very fast indeed.

bingo is a military term. The regulator has strict rules regards minimum fuel. So how many minutes flying is that in an F16?

if you had committed, or were planning to land close to reserve, and something changed (drone alert is my biggest thought here or short term runway blockage, you may end up in a mayday fuel whilst enroute to diversion. The drone thing has influenced how I plan - I will always have another piece of tarmac up my sleeve just in case.

London is well served anyway, with Stansted, Gatwick, Heathrow, Bournemouth and Birmingham in close proximity. All are good for a wide body.

most airlines fly off stat contingency these days. Enroute alternate is something we only seem to do when building the stats on a new route.

Unless the definition of emergency has changed, why would a diversion ever fall into this category?

Quote from a training handout:

"The “MAYDAY” declaration is used when all opportunities to protect final reserve fuel have been exploited and in the judgment of the Commander the flight will now land with less than final reserve fuel remaining in the tanks."

The diversion itself is no reason to declare a MAYDAY, it's down to how much fuel you have left.

EASA OPS CAT.OP.MOA.280 (b)(3)
The commander shall declare an emergency when the calculated usable fuel on landing, at the nearest adequate aerodrome where a safe landing can be performed, is less than final reserve fuel.

Challenge is when more aircraft does it simultaniously, declare emergency.

One aircraft declaring emergency is relatively easy to handle, but if several aircraft follow, due to a "he did it, then I can do it"-mindset, it may spark a lot of problems, especially for those who are in the most dire situation, since they may end up behind someone who could have been in holding for an additional 5-10 minutes.

Not saying the mindset is something that is likely to happen, it's may still be a danger.

Like LookingForAJob said.

I believe the questions that need to be answered are :
1) Is it confirmed the 3 aircrafts actually declared a mayday fuel or did they opt for a minimum fuel / PAN call and ATC has asked them to squawk 7700 for their own London Area Ops ?
2) In case of a multiple mayday call by 3 aircrafts diverting, what is the root cause ?

Being clear on the above could be helpful.

Three possible areas of consideration ...
1 Single seater - self-concerned and relatively unrestricted
2. Pax conveyor with commercial and other limitations
3. ATC controller(s) with multi inputs, coordination (traffic) problems.
The question is posed, perhaps unsurprisingly, by 1.

How long does it take for a controller to organise one diversion??? That time can take you from no emergency to MAYDAY pretty easily. I did STAC at Swanwick last year and a figure was quoted, I just can't remember whether it was 10 or 15 mins...

Part of the problem in the south east of the UK is that if you need to divert to your primary flight plan diversion, but they won’t accept you, ATC end up saying “you know what you need to do”. We shouldn’t be having to call MAYDAY just to play the game to get to our nominated diversion and it goes somewhat against the convention of the standard phraseology regarding minimum fuel states. It’s not ATC’s fault and they’re always excellent. These days I always carry fuel to cover a non London alternate. It’s just not worth he stress.

It can easily be that long. We have to get approval from the airport before we can send you there and that's what takes the time.

For the actual ATC side of it, it's pretty easy. It involves us putting a new route into the computer to make sure the right sectors get your details, coordinating with the next sector if required and then telling you the route, except you probably already know that, but we have to tell you anyway

AFAIK only 1 a/c declared MAYDAY, however 3 others squawked 7700, not at the request of ATC. NONE declared PAN.

As for DIVs it is not uncommon for a named alternate to refuse the DIV, particularly LTMA airports on bad weather days/peak hours. With multiple DIVs at any one time workload becomes very high trying to find a suitable alternative which will accept the DIV as the request routes Aircraft - Terminal Controller/Area Controller - Supervisor - TWR - Airfield OPS and then back again which can (at times) take a lot of time.
Capacity restraints within LTMA airports make the current DIV process unfit for purpose and safety compromising which was realised during the recent storms. This is something the CAA should seriously look at.

and what happens as soon as we say the magic word? Permish goes out of the window. I guess this is where these guys got to. As soon as one called it, I bet the other two piped up pretty quickly.

The reality is not everyone is operating to this level of fuel, due to the range of flight durations and conditions encountered enroute. there is therefore a distribution of endurance as people hit the stack.

Problem is, there are the unknown unknowns (not talking about your prob 30 tempos that turn out far worse) like drones or security events in the terminal. Statistical contingency can’t account for this, neither can 5%/5 mins holding on a short sector.

Airlines have an overriding responsibility for safety, but also consider operational efficiency.sometimes benign conditions together with modern commercial, very accurate planning systems, when a “black swan” event occurs can really screw things up. We don’t use string on a map, fold lines or rules of thumb.

anyhow, something must be working. When was the last time aircraft were falling from the skies with dry tanks? What helps is London Air Traffic being literally awesome and by far the best controllers we work with. East coast USA? Bad weather at destination? Give me another two tonnes minimum.

Military flying generally involved filling the tanks or going up to MTOW as you need the operational flexibility it gives in theatre with turd atc and no proper support on the ground, not to mention “the fog”, plus operating with a vastly inexperienced (but well meaning) operational control structure. The commercial world has comparatively a far more benign operational environment, with far greater comms capability and very experienced people on the ground (multi decade experience) with data from acars and lacking a lot of the fog of war. This means you can SAFELY plan to lower margins of fuel.

If you divert from overhead destination with your normal reserves, you should be able to fly to the alternate and land still with 'final reserve fuel' on board; there is no need to declare an emergency of any sort. If you are go below final reserve fuel, you must declare a Mayday.

If you set off on a diversion and have to declare Mayday straight away, then something has gone wrong. Either the crew held for too long and have started the diversion below the normal reserves or the fuel planning was wrong, by which I mean maybe an unrealistic route from destination to alternate was catered for.

Couple of scenarios. Previously issued ET becomes invalid as it’s taking longer to clear the runway. With an ET you can hold below diversion fuel.

airspace congestion led to longer routing.

aircraft told of ET at diversion, or in organising diversion, that meant they would be landing with below reserves level of fuel.

Say the magic word, all stops are pulled, having been in a similar situation in the Middle East with an intransigent host nation trying to make a political point resulting in us having no diversion option, other than the country we were filed to land in.

Would You really burn your alternate fuel in the hold while waiting the runway to be cleared / inspected on an airport without independent runway OPS ?

I guess you didn't read the thread. First of all, no, you do not declare mayday only once you are below final reserve fuel, you declare it as soon as you are reasonably sure that you will land with less than final reserve fuel. Which can be at a time where you are still quite a bit above final reserve fuel. Not to mention, at some point the low fuel warning of the aircraft will come on, that is a LAND ASAP amber indication which could be interpreted as reason for a PAN or MAYDAY depending on how you are trained.

And as has been explained in here, you fly to your destination, you do the approach, missed approach, decide straight away you want to divert, and ATC tells you to stand by for 15 to 20 minutes. That is an amount of time that is not included in your alternate fuel. You are straight away in a mayday situation as you will land below final reserve fuel. Of course, there could be contingency fuel, if that hasn't been used before, but that is at minimum only 5 minutes worth of holding. You still have to wait another 10 to 15 minutes until ATC has sorted out the approval, routing and so on. Still a mayday situation.

Of course, we could always take those 15 minutes as extra fuel. And personally i like to take 20 minutes into the london TMA simply because they advise us that "no delay" means up to 20 minutes of holding. But during a low season day to your homebase in benign weather? Probably not.

Agree on the above. I believe that all those kind of considerations should be embedded in the fuel planning regulations at EASA level. If I have the legal amount of fuel at all times and take my decisions accordingly I can't end up in an emergency because TMAs are busy and ATCs need to coordinate diversions and so on. I mean if that is always case it is perfectly fine and understandable given the amount of traffic nowadays, but the rules should take it into account and EASA should intervene through the appropriate channels to ensure Operators plan fuel accordingly.

Multiple simultaneous fuel emergencies declared?

Sounds to me like a systemic aspect exists here.

Company policy (aka local training department) browbeating crew to fly with minimum fuel and some delay occurring (this pressure has been a persistent problem in several companies as we well know) - suddenly several of that company's aircraft are trapped in the hold and crews begin sweating. All know what they ought to do but human nature being what it is hold off on the hope of a reprieve in another three or four minutes to save the interview and all the paperwork - and possible pointed fingers...finally someone has the sense to do what everyone is thinking and the dam bursts; there is a relieved cascade of MAYDAYS from crews who are thinking, well, at least it isn't just us...

Just surmise you understand...

If I have been given an ET off the hold by ATC, and I think its realistic, yep. I would have a brief discussion with ATC emphasizing the situation to ATC though, together with any margin above declaring a Mayday.

That is also what everybody else would be doing in that exact same position unless they have loads of extra fuel for no reason. Having multiple airplanes declaring mayday in the same TMA due to fuel on a fair weather day is not normal (nor it would be even on a stormy day). As I have written in another post, it is fine if ATC takes some time to coordinate diversion / routings, just highlight it to regulators / operators so that everybody can plan accordingly. No pun intended to the specific airline, they fully abide by the rules.

You wont get an EAT if runway is closed, it’s delay not determined.
would you really plan your fuel on the basis of an estimate of how long it was going to take to remove a stricken aircraft or for a concrete patch to dry?

was that the reason for the closure? No, of course not. But if it’s for an extended runway inspection due to a shedded tyre, yes I would. It’s all context. This job rarely is black and white. That’s the difference between a GA enthusiast and a professional pilot.

A small patch of runway break up, resulting debris and subsequent quick dry patch, I believe was the reason.

It would still be delay not determined if the reason was to allow someone to drive the length of the runway picking up various sized and amounts of shredded rubber for obvious reasons.

The only times I’ve diverted from LGW when the runway was closed, the response from ATC went along the lines of.. LTN is full, STN and BHX will accept you if you declare an emergency, there is space at EMA or the next available airport is LPL... not sure if this is relevant to the OP but as has been said, with the flow rate into LGW, when the runway shuts, the surrounding airports fill up very quickly.