Ed Helicopter Crashes into Glasgow Pub

Skwinty said:
Bearing in mind that the helicopter was at an altitude of 1000' AGL, there was very little time before impact to analyse and correct any apparent fault. The pilot could have believed he still had another 10 minutes of fuel left. Had the rotors not already stalled there still would have insufficient time to correct the fuel configuration and effect an engine restart.
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At the risk of over-repeating myself...... how could the pilot reasonably have believed he still had another 10 minutes of fuel left? He had perfectly-functioning, entirely-accurate fuel gauges right in front of his eyes, which showed him explicitly that he had no fuel left! Oh, and he also had a series of escalating low-fuel alarms that were explicitly directing him to the inexorable conclusion that his engines were about to run out of available fuel.

I think that any analysis of the pilot's actions post-flameout is a slightly separate matter. I fully agree that the pilot may either have become over-rushed, panicky, struck paralysed with fear or done the wrong things once both engines failed - especially if he had relatively little time in which to react before the aircraft hit the ground (however, I'd add that he could and should at least have initiated an autorotate procedure, and I believe that the aircraft could potentially have made a safe hard landing under the circumstances).

But what I find very hard to believe is that the double engine failure can have taken the pilot by surprise. I also find it very hard to understand all the actions and inactions up to the point where the engines flamed out. I find it very hard to understand how and why the pilot either a) failed to respond altogether to the multiple "low fuel" alarms, or b) did respond to them at some point but then did not notice that his response had had zero effect upon the problem (which, instead, was escalating in nature). Why didn't the pilot land the aircraft? Why did he elect to fly back towards his base right over the centre of Glasgow on a busy Friday late evening?

You know that situation that sometimes occurs when you are driving (most commonly on a motorway (freeway)) and your low fuel warning light comes on? It's only usually a small light, sited next to the fuel gauge itself. But I guarantee that virtually every driver sees and understands that warning light when it comes on. In addition, the consequences of running out of fuel in a car are extremely annoying and inconvenient, but are very rarely dangerous and almost never potentially fatal. In an aircraft, by contrast, the consequences of running out of fuel are obviously potentially extremely serious, and often fatal. Therefore, a) the alarms system is extremely alerting - particularly in modern aircraft such as this EC-135, and b) pilots are exhaustively trained and tested to watch out for the fuel situation constantly, and (more importantly and relevantly) to react immediately and effectively to any alarms. And if they cannot solve the "low fuel" problem, to put the aircraft down safely if at all possible before the engines run out of fuel completely.

In addition, going back to the car example, once the "Low fuel" warning light goes on, have you ever found yourself staring at the needle gauge, thinking something like: "I bet I've got about 20 more miles' fuel left - there's a petrol (gas) station right here but I'd prefer to go to the next one, and I'm sure I'd make it"? Many have. Some have been guilty of bad misjudgement, and have ended up coasting to a stop by the side of the road when they run out of fuel (and having to walk miles to fill up a fuel can). Too bad. But aircraft pilots clearly cannot afford to adopt this sort of cavalier attitude. If they misjudge it, they possibly lose the aircraft, and they possibly lose the lives of themselves, their passengers, and perhaps people on the ground. And that's why there is such a strict and non-negotiable protocol that must be followed for a "low fuel" emergency on an aircraft:

1) Keeping the aircraft in stable, level flight, confirm the exact nature of the problem;

2) Apply corrective action (ideally by running through the appropriate written checklist);

3) Monitor closely to see whether the actions performed have corrected the problem (in this case: have the alarms stopped? are the supply tanks visibly refilling with fuel?);

4) If the problem is solved, carry on with normal flight while remaining extra-vigilant to the situation to see whether it (or any related problem) might reoccur. Best practice is to radio back to report the problem and its solution at this point;

5) If the problem is NOT solved (in this case: alarms not going off but actually increasing, levels in supply tanks continuing to dwindle towards zero), immediately look to land in a safe place, if at all reasonably possible. And make an immediate radio call to outline the situation;

6) Do NOT, under ANY circumstances, either a) ignore the problem, or b) fail to carry out step (5) if you cannot solve the problem satisfactorily. And beyond a shadow of a doubt, do not attempt to fly an aircraft in this condition directly over the densely-populated centre of a major city.
 
IIRC the operating manual says when the low fuel alarm activates the pilot should land the helicopter within 10 minutes.
 
Skwinty said:
When the rotors are not turning the pilot cannot aviate or navigate.
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Well, technically-speaking, an autorotate procedure falls under the definition of aviating. But clearly navigating is out of the question.

My father once hard-landed a Hawker Hunter (back in the day.....) when the entire landing gear had jammed in the retracted position. He knew the nature of the problem, and he had been trained how to react to it appropriately. He executed a textbook hard landing, causing only surface skin damage to the aircraft, and received a military medal for his actions.

But his view (and one that was shared by all his fellow military pilots) was that he was doing nothing more than that he was trained to do, and his only accomplishment was to execute the procedure properly as required. He didn't do anything extraordinary or "heroic". But nor did he panic, freeze or react incorrectly. He was properly trained, and of the proper character for the job.

And in my opinion, a helicopter pilot who finds himself with a total loss of rotational power (and thus lift) should be adequately trained, and of adequate character (since (s)he has passed certification) to identify the problem immediately and to apply the correct remedy: in this case, an autorotation manoeuvre. All the evidence from eyewitnesses in the Glasgow case indicates firmly that the pilot did not even initiate an autorotation: the aircraft just fell with level attitude out of the sky.

As I have said many times before, however, I can understand how this part of the accident - if taken in isolation - might be explained as either a failure of training, pilot panic, pilot incorrect inputs or pilot freezing. It was a fast-moving situation that required instant action. Some pilots just fail when they are given this sort of ultimate challenge. But what I cannot understand is the entirety of the pilot's actions and inactions, including the failure to deal with the flameouts, but (more importantly) including every input (and non-input) and every decision from the start of the first "low fuel" alarm several minutes earlier.
 
Skwinty said:
IIRC the operating manual says when the low fuel alarm activates the pilot should land the helicopter within 10 minutes.
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It says exactly that: provided that the pilot has not managed to satisfactorily correct the problem.

In this instance, it is self-evident that the pilot failed to correct the problem. And it's also beyond all doubt that the pilot must have known that he had failed to correct the problem. He should have set the helicopter down on a playing field or other clear green space (or even a large car park if empty), of which there would have been plenty in the immediate vicinity of his flight path.
 
The conditions required for successful autorotation are high forward velocity and high altitude. High forward velocity and low altitude like 1000' AGL does not satisfy the requirement. Same with low forward velocity and high altitude. On loss of power the pilot needs to immediately lower the collective pitch to 2 degrees and nose down to maintain rotor speed. The pilot should flare and increase collective pitch just prior to impact to soften the landing. I don't think the conditions for successful autorotation were present for this particular accident
 
Skwinty said:
The conditions required for successful autorotation are high forward velocity and high altitude. High forward velocity and low altitude like 1000' AGL does not satisfy the requirement. Same with low forward velocity and high altitude. On loss of power the pilot needs to immediately lower the collective pitch to 2 degrees and nose down to maintain rotor speed. The pilot should flare and increase collective pitch just prior to impact to soften the landing. I don't think the conditions for successful autorotation were present for this particular accident
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1,000 feet is absolutely not considered "low altitude" for the purposes of an autorotation manoeuvre.

Nearly every small helicopter can make a safe autorotation landing from far, far lower altitude than that, even with zero initial forward speed. I am trying to locate the specific HV curve for the EC-135 - which will show the safe operating envelope for the aircraft at any given height and velocity (with the shaded areas representing no-go zones).

As an example, though, here is the HV curve for a Robinson R44, which is fairly comparable to the EC-135. It's the graph that is shown at the bottom of the webpage:

http://blog.aopa.org/helicopter/?m=201112

You will see that at Sea Level, anything above 400 feet is in the "OK" zone for autorotation, even at zero forward speed.

If I (or anyone else) can locate the specific HV curve for the EC-135, that would provide the totally accurate information we require. But I would suggest that for the EC-135, 1,000 feet at 0 knots is more than adequate height for a successful and safe autorotation landing.
 
LondonJohn said:
He appeared to be consciously and deliberately piloting his aircraft - an aircraft in which escalating "low fuel" alarms were blaring out, and where the fuel gauges in front of the pilot's eyes were rapidly bleeding out to zero - back towards his base, taking him over the densely-populated centre of Glasgow.

Can you explain that?
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I wonder if he intended to follow the course of the River Clyde. Both his destination, if that was the heliport, and the point of impact, the Clutha bar, are literally within a few yards of the water's edge.
 
I understood that with a cat a helicopter with twin engines and one engine inoperative (nevermind 2 inoperative) the hv diagram was of little use. I of course stand to be corrected.
 
LondonJohn said:
At the risk of over-repeating myself...... how could the pilot reasonably have believed he still had another 10 minutes of fuel left? He had perfectly-functioning, entirely-accurate fuel gauges right in front of his eyes, which showed him explicitly that he had no fuel left! Oh, and he also had a series of escalating low-fuel alarms that were explicitly directing him to the inexorable conclusion that his engines were about to run out of available fuel.
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There would have been some confusion with what he was seeing(and hearing). The first fuel alarm that normally would sound would be the low main tank alarm. That would not have gone off and the gauge would show fuel in that tank. The first alarm he got was the feed tanks were running low and if he thought he corrected this with the pump switches, he could think it was an instrument problem. He would have seen fuel on the gauge.

Naturally this is all speculation.

ETA:

This is what he would expect to see:



Instead the center part would still be partially blue.
 
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There is a class of error where you believe you have done a certain thing, for example you reached up and toggled some switches, and then it is out of your world while you deal with other things. You don't even consider that the thing isn't done when you interpret the condition you are seeing in front of you.
 
BenBurch said:
There is a class of error where you believe you have done a certain thing, for example you reached up and toggled some switches, and then it is out of your world while you deal with other things. You don't even consider that the thing isn't done when you interpret the condition you are seeing in front of you.
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Yes...no doubt. And that type of error is very dangerous for pilots.
 
SUSpilot said:
Massive screw-up, either ignoring the systems or not comprehending them.
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Fair enough..... up to a point.

My own personal point of view is that while I completely understand that cases of pilots ignoring or not comprehending alarms is not uncommon (and is often a significant factor in CFITs), I just can't see how it can have been the explanation in this case.

Why do I think that? Because there was simply so much explicit evidence sitting literally right in front of the pilot's eyes and in his ears. It would have been functionally impossible for him to fail to notice that alarms were sounding and flashing. It would also have been impossible for him to fail to notice that these alarms were not stopping, but were instead increasing in number and urgency.

So, at that point, we have to believe (in my opinion) that the pilot knew that the aircraft was telling him that there was a serious problem that was only getting worse. And therefore, we have to speculate as to how the pilot might have reacted. Is it reasonable to suppose that he simply ignored the alarms altogether? In my opinion, no. Is it reasonable to suppose that he thought the alarms were false alarms and therefore decided to discount them? Possible, I guess, but why would he do that?

Perhaps in order to address this question, we should ask whether it's possible that the pilot misinterpreted the nature of the alarms. For example, could he mistakenly have thought that the alarms pertained to the hydraulic system or some other system? Possible, I suppose, since I am not explicitly aware of the exact nature of the "low fuel" alarm in the EC-135. But even if that were the case, the nature and urgency of the alarms ought to have told the pilot that the aircraft was screaming out to him that something was going critically wrong on the aircraft. There's no question in my mind therefore that he should have cut his losses in any case and landed.

But for the moment, let's suppose that the "low fuel" alarm in the EC-135 is very clear in referring to the fuel in the supply tanks. Maybe the pilot thought that it was a false alarm. But if so, I cannot conceive of a situation where he wouldn't have looked at the fuel gauge instruments that were right in front of his eyes. And it could not have been clearer to him - in both graphical and numeric terms - that the fuel in the supply tanks was running rapidly towards zero.

At this point, one thing does occur to me. Is it possible that the pilot looked at the fuel gauges, saw the 80kg-odd of fuel in the main tank, and misinterpreted it as fuel that was available to the engines? It's clearly a possibility. Could the pilot then have thought that all the alarms were false alarms, and that the alarm systems must (in his mind) have been faulty - since (in his mind) he could see that there was plenty of fuel?

Well, that's a possibility. But it would require the pilot not only to make a massive error in his interpretation of the fuel gauges, but also to make a stunningly bad choice as to which indicator was reliable. After all, even if the pilot thought he was looking at a gauge which showed him ample fuel available to the engines, why couldn't (in his mind) that gauge have been faulty, rather than the alarms? It's basic aviation discipline that if your instruments conflict, you should always take the most pessimistic (or worst case) option as your assumption - and you should always try to apply the ultimate remedy of putting the aircraft safely on the ground if the discrepancy is over something as vital as fuel supply.

And if we suppose that the above is what happened, we also then have to suppose that the pilot kept flying normally, with the alarms getting louder, brighter and more urgent, all the while thinking nothing except "Damn this malfunctioning "low fuel" alarm system - I'll have a proper go at the maintenance people when I get back to base". Surely, as the alarms increased in nature, the pilot would have had the sense and the training to think something like: "Hmm, I'd better just check that my reading of the fuel gauge is correct, and that I'm pretty certain that we do have enough fuel getting to the engines - after all, the consequences of me being wrong are catastrophic, and these alarms are just getting louder."

Plus, as I said, he shouldn't even have been having this sort of internal dialogue in the first place: if there was (in his mind) a fundamental conflict in what the alarms were telling him and what (he thought) the fuel gauge was telling him, he should clearly have erred on the side of caution and landed the aircraft safely.

In other words, I think that for the pilot to react (and not react) in the way he evidently did to the alarms would have required a sustained succession of extraordinarily bad decisions on his part - not just one bad decision (which is obviously a lot more feasible). For a pilot of his training and experience, it (to me) is simply incredible to suggest that he treated a "low fuel" emergency in this way, when he cannot but have known that the consequences of getting it wrong were so potentially catastrophic. Could he really have been that cavalier and/or incompetent? Personally, I find it hard to accept that he could have been. But I hope that I'm wrong, or that there's some other explanation altogether (e.g. brain incapacitation) that fits the evidence.
 
I remain pretty shocked at the single-minded selective interpretation of the limited data available to conclude that the pilot deliberately crashed the helicopter.

Rolfe.
 
BenBurch said:
There is a class of error where you believe you have done a certain thing, for example you reached up and toggled some switches, and then it is out of your world while you deal with other things. You don't even consider that the thing isn't done when you interpret the condition you are seeing in front of you.
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I agree in principle. But in this case, what else might the pilot have been preoccupied with ("dealing with other things")? Of course we'll never properly know the answer to this question, since all those on the aircraft are dead. But there's certainly no evidence at all that there was any other thing that might have preoccupied him: there was nothing else malfunctioning on the aircraft; he must have known pretty accurately where he was (this was his usual area of operation, and also the city lights were a clear guide); there were no unusual weather conditions; he seems to have been flying the aircraft in a non-urgent path; and he made no radio communications (if, for example, one of the passengers had suffered some form of medical emergency, one would have expected the pilot to radio back this information, together with a request for medical assistance on the ground).

And if the pilot considered that he had remedied the situation by toggling the switches, then one then has to consider what happened next. The alarms quite evidently did not stop in reaction to his "remedy". Instead, they got worse. Can we suppose that the pilot toggled the switches, then dismissed the ongoing and increasing alarms with an attitude of "Oh shut up will you! I've sorted it out!"? Or ought we to suppose (as I think we should) that the pilot would/should have thought something along the lines of: "Hold on. I thought I'd fixed that problem. The alarms are suggesting to me that there's still a problem. I'd better have another look."?

Again, I find it difficult to accept that the pilot, having made the initial error of toggling the switches incorrectly (which I full agree might have happened), then totally ignored the escalating emergency warnings. There's simply no way (in my view) that he can have "considered the thing done" when he "interpreted the condition he was seeing in front of him". After all, the condition he was seeing in front of him was a series of loud, urgent alarms, telling him unequivocally that he had a "low fuel" emergency. And he had a fantastically user-friendly and intuitive fuel gauge right in front of his eyes, that was explicitly confirming the situation.


I am a scuba diver. One of the critical things when scuba diving is to monitor your remaining air supply. Once it gets to around 80 bar, it's timeto begin your ascent. Otherwise you risk running out of air, and that has catastrophic - and potentially fatal - implications, especially if you're at 20 metres or below.

Now, it's entirely incumbent upon the diver (and, to a certain extent, the diver's buddy) to visually monitor his/her air gauge. In the vast majority of cases, this is a simple analogue needle gauge - and consequently there is no facility of having any sort of automated warning system. If the diver (and his/her buddy) neglects to look at his/her air gauge regularly, or if (s)he misinterprets its reading, then there's nothing to stop the situation where the diver eventually tries to breathe in and nothing happens because there's no air left in the tank.

And plenty of scuba divers die or are seriously injured in exactly this way: they get preoccupied in some way, or simply forget their training, and forget to monitor their air gauges, then find themselves suddenly out of air at (say) 25 metres. Even very experienced and highly-qualified divers have been known to make this catastrophic mistake.

But......... I can be virtually certain that if there were a system of warming alarms available that informed the diver that (s)he had a "low air" situation, with further and more extreme alarms kicking in as the air got closer and closer to zero, NO properly-trained diver would ever let their air run to zero - unless they were medically incapacitated in some way. Even the hubristic, arrogant, know-it-all types would know beyond all doubt that the ramifications of running out of air are extremely grave.

As Richard Feynman said after his devastatingly-effective "rubber o-ring in a glass of iced water" demonstration in the Challenger Disaster Inquiry: "I believe that has some significance for our problem" (although obviously it's not a perfect comparator).
 
Rolfe said:
I remain pretty shocked at the single-minded selective interpretation of the limited data available to conclude that the pilot deliberately crashed the helicopter.

Rolfe.
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Careful. You are agitating again using a strawman.

I am suggesting that in my opinion it's difficult to marry the known evidence (which appears to be reliable, objective and in-depth) with the usual human factors that underpin many aircraft accidents. I am suggesting that one way of explaining the evidence is that the pilot, for some reason, consciously opted for a course of action that he knew had negative consequences.

What I am NOT doing is "concluding" that "the pilot deliberately crashed the aircraft". What's more, I am actively searching for other reasonable explanations (including, for example, certain medical situations), and nor am I even suggesting that I am right in my opinion that this was not a "vanilla" case of pilot error. I might indeed be wrong. It's just my opinion, and that's all it is. I have not drawn conclusions (even tentative ones), and nor have I made a single accusation against the pilot (apart from the now-undeniable fact that pilot error (regarding the position of the fuel pump switches) must have played at least some part in the tragedy).

What the heck is going on here? Do you seriously have to try to remake this point over and over and over? Give it up. Tell me how and why you might disagree (or agree) with all or parts of my opinion. Tell my how and why you might think that other opinions have more validity. But stop with the nonsense. Please.
 
Skwinty said:
I understood that with a cat a helicopter with twin engines and one engine inoperative (nevermind 2 inoperative) the hv diagram was of little use. I of course stand to be corrected.
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I am not sure I understand what you're saying here (I don't have a great deal of familiarity with helicopter-specific parameters such as these, and have no experience of dealing with HV curves in practice). Could you elaborate a little more to explain what you mean? Thanks.
 
The autorotation parameters for the EC-135 are partially indicated in this extract from the flight manual:

http://helicopterindia.com/yahoo_site_admin/assets/docs/FM-EC135P2.24193407.pdf

Section 3.4.14 covers the autorotation procedure. It states that the flare manoeuvre should be performed at 100ft and a recommended airspeed of 75 knots. I believe therefore that from a starting position of 1,000 feet and zero knots, this should be an easily-attainable procedure.

Frustratingly, the HV curve itself is provided in Section 5 of the flight manual, which I cannot currently find online. However, I am now very highly confident that 1,000 feet and 0 knots will lie well outside the shaded no-go zone, and that therefore it is a perfectly safe starting position to initiate a successful autorotation landing.

(re "buildings" etc, these are of limited relevance in heigth calculations in the magnitudes that we're taking about. The vast majority of buildings in the vicinity of the helicopter at that time were three- or four-storey structures at most - meaning that they rose to around 75 feet at most. Any taller buildings were few and far between, and could (and should) have easily been noted and avoided by the pilot, who still would have had full electrical and hydraulic control of the aircraft.
 
The issue to consider is this. The helicopter is flying at 1000' AGL over a city and not an autorotation practice field. The pilot receives low fuel warnings and rightly or wrongly assumes 10 minutes flight time remaining. He calculates that he should make home base albeit with less fuel remaining than is legal. For whatever reasons, as yet undetermined, the engines stop running. The clock starts ticking and even if the pilot had successfully initiated autorotation the ground is at best 30 seconds away. That is not a lot of time to resolve the problem. After all, this was not a daytime autorotation training exercise over the airfield. Now I am not saying that autorotation cannot be successfully carried out at low altitude during a training session because the pilot is preparing and expecting to perform the manoeuvre. It's a different scenario when the need arises at night unexpectedly. In any event, altitude and forward velocity are crucial in ensuring a successful autorotation. There is no need to assume criminal or negligent intent on the part of the pilot.
 
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