Yes, but what about a contaminant that floats on top of the fuel? Harmless till the tank runs low enough for it to be ingested, and drain checks would never show it.

Perhaps obvious - maybe it's even suggested to some u/t pilots theses days - but a thought re communicating a problem.....
I worked as an ATCO offshore from 1980 to 1982. The calm was shattered one morning when an inbound (Puma or S61) suddenly broadcast a Mayday, the callsign &, to me, what sounded like a check list & lots of numbers.
All tx/rx was, of course recorded by ATC.
He landed ok on his nearby destination platform & later called me to say he'd had a warning light(s) & was broadcasting some parameters that investigators would like if it had gone wrong & they'd ended up swimming. Smart thinking in a dodgy situation before cvr's .... :D

@DAPT and how many real emergencies have you been involved in when a Mayday was required? I'm talking life threatening emergencies. It is always a little different when you are sitting at the controls of a properly out of control helicopter that seconds before was behaving normally. Go figure as they say.

DAPT

The Mayday call is well ingrained as part of a drill when we recognize what has happened and we are executing the actions that we know intimately. If you have a really unusual situation, and you are concentrating on working out what you are going to do whilst the ground rushes up at you, I rather think it is going to slip down the priority list.

If that's the way you think you'll be able to do it fair enough DAPT, however it is well known that we can't concentrate on 2 things at the same time, we can multitask, but not concentrate on more than one thing at a time. Throw in an unexpected or multiple emergency and I'll bet that call gets shoved to the back of the list. My training involved putting out a call, if there was time, once the situation allowed.

Eric, nice post. Flying around our local city the other night, I was under no illusion that if I managed to get a call out, the first thing after the Mayday & c/s would be the problem/symptoms. Not SOP I know!

Cabby, Turbomeca or P&W ?

I must ask, before or after TDP? I know neither of the engines failed as such, but to stop the take off (rejected before TDP?) and return to stand!
I know I wasn't there, etc etc, but I think I'd rather leave it in situ, than continue flight.

DAPT

The pilot in this case was previously military.

Mil Rotary use the WADFIR principle for dealing with emergencies.

Warn the crew
Achieve Safe Flight or Land
Diagnosis
FRC Actions
Intentions
Radio Call

However the principle can be tailored to suit the nature of the emergency. Note that Radio Call comes last and is done if possible and time permits.

I think that in this case, the pilot had enough to contend with in trying to achieve the second item in the best way possible at night, in an area with very few options.

I've seen some struggle to achieve all of this in training with the luxury of advanced notice and height and be able to achieve a full flare recovery, in daylight.

For all the armchair experts out there who are having a go at the AIB for not getting a preliminary cause out yet, give them a break! They must carry out the investigation thoroughly and and without jumping to conclusions. They have to determine what damage was caused prior to and after the crash. They have a mountain of evidence to sift through and must ensure they don't overlook any detail. I'm sure when they have the facts that they will report their findings.

Finally, I'd like to say, there is a lot of B0110x on this thread and some have you have demonstrated why you are not employed by the AIB or maybe you shouldn't even be employed within the aviation industry!

In the simulator with catastrophic type failures, I have observed decent pilots put out a perfect May day call then crash the aircraft. Others have not used radio and landed the aircraft. My brief is to make a call if it doesn't put the aircraft at risk. Stating you have 'failed' SOPs is quite frankly a load of bollocks

@Cabby:If only all of life's problems could be solved so easily with a little astrology...;)

Comment to non-aviators on the thread
 

The clue is in the meaning of the word "Mayday": "venez m'aider"; "come to help me".

I suspect the public think a helicopter is safer than an aeroplane because "it can land anywhere" but an aeroplane glides naturally, and thus there is normally more time available.

When learning and practising there has to be some framework and guidelines but always it's "first fly the aircraft". If you're going to crash a call just helps other find you.

On that theme, fitting data recorders won't make a flight any safer.

Finally, I don't know the statistics but it's uncommon for people on the ground to be hit when a small aircraft comes down, even in a city.

May I ask, what would a Mayday call have achieved here?

Wikipedia - Mayday

Quel dommage! Dommage votre français n'est pas un peu mieux. Mais ce n'est à prévoir si vous vous asseyez en Nouvelle-Zélande!

F&*k Google - just ask me - a well known print on T-Shirts in Asia!

Autorotation - is as close to "natural" that any helicopter can achieve.

Aviate, navigate, communicate and in the event of risk to life,
the captain is in charge, not the rule book. The AAIB is not a rumour network and will carry out its work with its usual thoroughness. Although it is reported that four out of five accidents are due to pilot error, it looks to me as though this was not one of them.

"Mayday Mayday tail rotor failure going down, 3 POB "

or

"Mayday Mayday engine failure going down..."

some useful information can be sent over the rt

I completely agree. For all we know, the pilot may have had only single figure seconds to react to the entire incident before the aircraft hit the surface.

Before implying criticism of the pilot's actions, firstly none of us was there in the cockpit.

The obvious question is: What difference would a Mayday call have made to the outcome?

An ATC response would have resulted in a questions and answer exchange and the ATCO most probably could have done nothing of use, except for beginning to locate the aircraft and to determine the nature of the problem. By the very nature of this accident, i.e. over a populated area, folks on the ground were immediately aware of it - the very prompt reaction of the emergency services to the accident scene was reported.

Whatever happened appears to have been very sudden and I'm certain the pilot prioritised as well as he could in what was obviously a most dire situation. Sometimes things don't happen as a "text book" problem, such as they are practised in a simulator (or MS Flight Sim...) or talked about in the classroom. Some of the most worrying emergencies I've had to deal with in the air don't appear in the RFM. I've also had error messages come up that even the engineers didn't know about and that the aircraft manufacturer (initially) said did not exist.

In any emergency situation, the first priority has to be fly the aircraft and speaking to ATC is possibly quite a long way down the priority list, at least until under some sort of control because it detracts from the safety of the aircraft. It appears that poor Davey Traill never reached a state of affairs where a distress call got to the top of the hit list.

Mayday call-

Obviously your call sign - preferably 3 times if time permits.

N
I
P

Nature - Whats up

Intentions - What you are going to do

Position - Where you are (obviously)

Globally Universal format (hopefully)

Who hears it and to what extent is with luck.

Silo, re you post 722, it has of course happened, albeit different scenario and on the P1.


http://dms.ntsb.gov/aviation/Acciden...2013120000.pdf

Perhaps putting it into the Pub was the Mayday call as it surely got the message out didn't it?:ugh:

Come on folks....it's Sunday and the Pub is open....there's a better place to have this argument isn't it?

There is a scenario that might actually be the complete opposite to which you interpret as "good versus bad".

The assumption is that pilots actually know how these things work.

Unfortunately history has shown the opposite in some cases.

Mmm, I thought my post 722 was about the unlikelihood of inadvertently shutting down the wrong engine after an engine problem. The example you give is an inadvertent movement if the#1 twist grip out if it's detent and while manually controlling that engine, inadvertently moving #2 out of its detent. Did you read & understand your own link?

Of course on the T1 we know that the twist grips are smaller and we also know that on the T2, not only are the twist grips larger and have different textures, if the twist grip was to have been inadvertently moved out if it's detent (as in your linked incident), the CAD would display, 'TWIST GRIP' on the respective side thereby indicating to the pilot the problem, which is easily resolved by putting the twist grip back into its detent.

I think that all you have done here Cgb, is trawled the internet for a 135 incident where someone did something unexpected and somehow linked it to something unrelated. I guess this shows that knowing the 135 helps a bit in threads such as this.