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-   -   Police helicopter crashes onto Glasgow pub (https://www.pprune.org/rotorheads/528850-police-helicopter-crashes-onto-glasgow-pub.html)

Sky Sports 14th Feb 2014 21:50

Let's face it, it wouldn't be the first time that fuel mismanagement in a police helicopter has resulted in a crash.
Why did it all go wrong when it did? 'Pressonitis'

Tandemrotor 14th Feb 2014 22:28

JTobias

I couldn't agree more, and I will happily join you on that journey.

Wageslave

Certainly as far as the Mull Chinook is concerned, you clearly haven't got a clue what you are talking about!

I know I'll be slated for saying this by ignoramuses and holier than thou pricks, but I'm absolutely gutted for the guy. I certainly haven't ruled out the possibility that there is more to this than first meets the eye!

Senior Pilot 14th Feb 2014 22:30

Enough of the personal abuse and inappropriate language, please. I haven't the time to edit your posts but if you have an issue with each other; take it outside.

Tandemrotor 14th Feb 2014 22:35

How compatible with NVG was this cockpit?

JTobias 14th Feb 2014 22:55

SeniorPilot (Moderator)

Apologies for my language but whoever that guy is, he's not got the right to reply the way he did to my earlier post.

Tandem rotor - thanks

Joel

Digital flight deck 14th Feb 2014 23:15

Jtobias, give me a call and I'd be your wing man on that little jaunt.

SilsoeSid 14th Feb 2014 23:18

Sorry JT, I don't understand what you, as a pilot of both fixed and rotary aircraft, mean by;


I'm also guessing that there was not sufficient time for the pilot to react to the double flame out and as a result the RRPM decayed to an un-recoverable level resulting in the crash.
Do you mean he simply didn't react in time, or something else happened that stopped him reacting in time? If your 206 flamed out for example, what might cause you not to have 'sufficient time' to react?

JTobias 15th Feb 2014 00:06

Silsoe,

Don't you start! Were mates now !

And why do you feel the need to quote my 'credentials' you can clearly see that I posted that only because I was challenged in the original reply to my first post - don't you start adding fuel!

Now, to answer you, I don't 'mean' anything - my whole post is basically asking for a steer as to what might have happened to have caused him to not react quickly enough - surely my post is in plain enough language for anyone to understand that - I'm asking!!

For instance is it possible that his hand wasn't on the collective for whatever reason or that the collective was locked with friction or the autopilot was engaged and it takes 1 second to disengage but the RRPM decays in under that time.

In my machine, if my engine fails (god forbid) I get an engine out tone, I get un commanded yaw and I drop the lever quick. But my machine also allows me something like two seconds in which to do it. Does the EC135 allow such a time frame?

However, if I had a passenger who panicked and grabbed my arm or I was switching my pitot heat on or changing frequency at the point my engine failed maybe those action could cause me to react more slowly and the RRPM might decay to an un-recoverable point. In this case whilst the manufacturer might consider in a calm cockpit with no other distraction there is traditionally sufficient time to lower the lever there are factors like those I've described that might cause there to be NOT sufficient time to react. It's not rocket science!

If there were warning captions illuminated, aural tones, and procedures that he had to follow etc that distracted him, plus pax that might have been talking to him or were panicked causing him to not instantly realise that he'd had a double flame out then he may not have had sufficient (as in humanly possible) time to process the information that his brain was dealing with and consequently not lowered the lever quickly enough.

None of us were in that cockpit so no one knows what happened but I'm asking for a steer from someone like you who flies twins and understands the systems and processes that might have lead to that. Finally, should the fuel transfer switches been on or off, because I don't think that's been answered.

The point is, I don't know, which is basically why I'm asking!!!!

Come on Silsoe! I'm relying on you for a sensible answer now that you've waded in!

Joel :ok:

JTobias 15th Feb 2014 00:17

Digital flight deck,

Thanks !

Joel :ok:

helmet fire 15th Feb 2014 00:54

Helicopter certification standards must permit RRPM to be recoverable by a "reasonable" pilot and that generally means at least 2 seconds must be available. When flying an incredibly reliable twin, double engine failure possibilities seems so remote compared to being on the edge in the 206 all the time given the immediate consequence presented by the failure of one engine in a single engine machine.....

The recognition keys are the same in all machines, so it reacts just like yours to complete loss of power to the drive train, though apart from the yaw you mentioned, pitch movement is also a key factor. It is really here that individual machines behave individually, some pitch remarkably, some hardly move and have advanced mixing units to cope, some pitch up (rare), some pitch down (more common) and some even change depending on configuration : floats fitted, winch fitted, external tanks fitted or even emergency floats deployed.

Ranger One 15th Feb 2014 02:23

I don't know one end of a 135 (or any other rotary device) from the other. But I have a small interest in this accident for personal reasons (no names no pack drill). I have a couple of questions about The Book:

What are the single engine failure checklist/action items on this aircraft, according to The Book?

There has been some discussion about the low fuel warnings and systems behaviour, flight time remaining from low fuel warning etc. What does The Book say about how the position of the transfer pump switches affects this scenario? The behaviour here must have been tested, explored and understood during certification.

I'm speaking strictly as a fixed wing pilot here. A single engine failure on a twin is routine. A single engine failure *following low fuel warnings* would ring my alarm bells good and proper, have Gimli flashing before my eyes, and have me thinking "oh sh!t I've stuffed up my fuel management" - would a prudent rotary pilot not be thinking *land immediately* in that scenario?

MightyGem 15th Feb 2014 04:09

Re NVGs. If the unit was cleared to operate with them, and if the aircraft was "NVG serviceable" on the night, then given the dark lumpy areas up there, the crew would probably wearing them. We always did.

Also, if the above is true, then the cockpit would be completely NVG compatible.

As to why both Transfer pumps were off, with all the constant switching on and off as they illuminate in the cruise and hover, as some operators do, perhaps that's why in 15 years or so I never did. Just left them on to work when they were re-immersed in fuel.

I can't recall any incidents of premature pump replacement.

John Eacott 15th Feb 2014 04:56


Originally Posted by MightyGem (Post 8319837)
Re NVGs. If the unit was cleared to operate with them, and if the aircraft was "NVG serviceable" on the night, then given the dark lumpy areas up there, the crew would probably wearing them. We always did.

Thanks MG.

So how would the NVGs impact on looking up and back to identify the load shed? Any other possible distractions/restrictions that could be created by the goggs on the front of the helmet or by the restricted field of view; just stabs in the dark as we acknowledge that something out of left field has apparently been confirmed by this interim report.

robdean 15th Feb 2014 05:06

When an experienced pilot crashes a fully functioning aircraft in broadly benign conditions there is commonly an issue of cognitive psychology in play. In other words, some 'software bug' of the human mind or perception from which none of us can ever be entirely immune. I remember a phrase from my psychology degree: 'we are free to construe but bound by our constructions'. In other words, you can make sense of things in any number of ways, but once you have made sense of things it can be inherently difficult to step back and identify mistaken assumptions. This can be a vicious trap in an emergency situation, where perception is narrowed and time is short.
In other words, it's worth considering whether the pilot became cognitively disoriented. That need not mean spatially disoriented. There are plenty of examples of crews intensely working a puzzling but irrelevant problem until CFIT, or becoming increasingly exasperated by 'spurious' cockpit warnings until the tragic moment when those alarms prove to have been functioning exactly as intended. The answer to 'But in that situation, every pilot knows to...' may lie in figuring 'What could possibly have somehow led him to doubt or be in denial that he was in that situation, just for long enough to no longer be within the recovery envelope'.

helmet fire 15th Feb 2014 06:57

:D :D :D

Agree 100% RD

At the centre of this there will be a lack of cognitive processing space available at a critical time. What will be instructive is why. What will be certain is that it could have been me.

MightyGem 15th Feb 2014 07:01


So how would the NVGs impact on looking up and back to identify the load shed?
Yes they can get in the way at times. Can't comment on any other distractions they may or may not have suffered.

Scuffers 15th Feb 2014 07:10

question for the 135 guys...

approx how long will 4Kg's of fuel last?

as in from the first engine flaming out, how long before the second one will quit?

AnFI 15th Feb 2014 07:20

RD quite right.
Maybe not much actually wrong just overcomplicated to death?
Needs two crew to manage this overcomplex cockpit scenario?


Under pressure the complexity of many pumps (with conditional performance), tanks, engines, goggles, several warning systems, alarms, horns, beeps, lights could lead to mental seizure.
and proceedures! (load shedding etc) (you wouldn't want to wast your time going through a drill in the 2 seconds you have to put a lever down)

Sky Sports 15th Feb 2014 07:22

2 minutes and 25 seconds (ish)

paco 15th Feb 2014 07:38

Ranger One:

Transfer pump switches are there for that purpose - I've not flown the 135 myself, but on the AS 350, you use the transfer pumps when you want to transfer fuel from one tank to another - nothing more, nothing less. Fuel boost pumps (and not all machines have them) must be on all the time. I would not necessarily read anything sinister from the fact that the transfer pumps were off in this case.

Fuel low warning lights typically come on early enough so that you don't have to land immediately, but as with cars, the prudent pilot doesn't trust them! For example, you have around 6 minutes on some helicopters, but call it three. But you should certainly land in a suitable time frame.

Talking of which, you are supposed to have 30 minutes on a battery when the gennies stop working. I wonder if this one was up to speed when running the electrics which are required to fly a machine such as this.


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