Helicopter down outside Leicester City Football Club
So speculation as ever but given what has been observed so far it seems most likely that:
a) The aircraft was high enough at the apparent point of failure to avoid hitting the TR on any part of the stadium or other fixed object
b) Therefore the failure was likely caused either by something else airborne hitting it - or some sort of separate mechanical failure
Assuming the mechanical failure option, (in the absence of any clear evidence of another airborne object) one thing that still puzzles me is why the pilot chose to lift to such an apparently unnecessary height before attempting to transition into forward flight. Could it be that he was aware of some sort of anomaly on the lift out that made him want to gain extra altitude to have the option of an autorotation away from the confined space of the take-off site? If there was a problem near the ground he would presumably have just put it straight back down - so whatever it was presumably occurred somewhere between the height at which he would normally have transitioned (200ft?) and the height he eventually reached (1000ft?).
To give this theory any validity, there would have to be some sort of anomaly warning (sound/vibration/warning system?) that would encourage the pilot to believe that continuing to gain height enough to attempt a safe autorotation was his best (or only) option. What might this have been?
a) The aircraft was high enough at the apparent point of failure to avoid hitting the TR on any part of the stadium or other fixed object
b) Therefore the failure was likely caused either by something else airborne hitting it - or some sort of separate mechanical failure
Assuming the mechanical failure option, (in the absence of any clear evidence of another airborne object) one thing that still puzzles me is why the pilot chose to lift to such an apparently unnecessary height before attempting to transition into forward flight. Could it be that he was aware of some sort of anomaly on the lift out that made him want to gain extra altitude to have the option of an autorotation away from the confined space of the take-off site? If there was a problem near the ground he would presumably have just put it straight back down - so whatever it was presumably occurred somewhere between the height at which he would normally have transitioned (200ft?) and the height he eventually reached (1000ft?).
To give this theory any validity, there would have to be some sort of anomaly warning (sound/vibration/warning system?) that would encourage the pilot to believe that continuing to gain height enough to attempt a safe autorotation was his best (or only) option. What might this have been?
It would also seem at this point that something departs the aircraft, but i'm not talking about the white speck seen at around 45 secs of the video doing the rounds, but the other white flat object which appears to depart the scene travelling up and left at approx 53-55 secs. (part of tail rotor blade?) I will try to provide a link to a youtube video showing this.
The media shyt regarding falling 'into a dead mans curve' (as if it is some mystical hell-like place that exists) is just laughable, and all of the so-called 'experts' that have been wheeled out and given their views, well, they've all either been seriously misquoted, or all talk absolute bollox to some extent. It's just as well that in the UK we have some of the best accident investigators in the world working on this. Some of the theories put forwards have been sensible and from the usual pro pilots on this forum, but the non-pilots who all suddenly become armchair experts do nothing but embarrass themselves when they put fingers to keyboards.
I think those of us who fly helicopters every day for a living, and have at least had some experience of tail rotor failures in simulators etc, will have a pretty good idea of some of the possible causes of this tragic accident, but unfortunately what we don't have access to are the facts except as shown in grainy videos.
So the media outlets will be trawling forums, and asking these crap-and-past-it experts for opinions based on poor real world knowledge, and a serious lack of facts. Again its a sad case of not letting the truth and fact get in the way of a good newspaper-selling story.
really? doesn't this even embarrass you writing something as stupid? so someone quickly ran out into the centre of a brightly lit football stadium, with some step ladders, probably had to remove a panel, drained the oil onto the field, then just walked away? honestly some folk need to go get a life. you've been watching far too much crap on tv.
Helimutt, thank you. It had to be said.
I guess you got fed up with all the 1 in a million theories and daft perceptions out there.
It seems incapacitation is the new buzz word on the street. I don’t know what the statistics are but I am pretty sure this doesn’t happen very often.
Sabotage, haha.
300 hour aircraft-Very new type into service is exactly why the reason this is most likely a TR gearbox/drive fault. Remember it’s bigger older brother, the 139, and the early days of tail pylons falling off and blades letting go.
There are dreamers and realists in this world. I guess it makes fun to have both types around.
I guess you got fed up with all the 1 in a million theories and daft perceptions out there.
It seems incapacitation is the new buzz word on the street. I don’t know what the statistics are but I am pretty sure this doesn’t happen very often.
Sabotage, haha.
300 hour aircraft-Very new type into service is exactly why the reason this is most likely a TR gearbox/drive fault. Remember it’s bigger older brother, the 139, and the early days of tail pylons falling off and blades letting go.
There are dreamers and realists in this world. I guess it makes fun to have both types around.
Yes, the gearboxes have "run dry" times. From memory the MGB is 53 minutes. I don't know about the IGB or TGB but they're under a lot less stress than the MGB.
As far as the "smoke/unburnt fuel" on engine start, it looks like steam to me. Had this quite a lot with 139 starts in cold weather with hot engines. Moisture would condense in the exhausts and give quite a good puff on engine start. Of course, the 169 doesn't have the monstrous exhausts of the 139!
I also note that the wind is up the tail on start.
Anyone know the critical wind quadrant/velocity for LTE????
Was the gear retracting on the climb? Unrelated but shouldn't it be after TDP when Vy is reached that the gear handle is moved? So hard to see details on the videos!
As far as the "smoke/unburnt fuel" on engine start, it looks like steam to me. Had this quite a lot with 139 starts in cold weather with hot engines. Moisture would condense in the exhausts and give quite a good puff on engine start. Of course, the 169 doesn't have the monstrous exhausts of the 139!
I also note that the wind is up the tail on start.
Anyone know the critical wind quadrant/velocity for LTE????
Was the gear retracting on the climb? Unrelated but shouldn't it be after TDP when Vy is reached that the gear handle is moved? So hard to see details on the videos!
Last edited by noooby; 1st Nov 2018 at 19:22.
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Just something to bear in mind when criticising two of the better qualified TV speculators.. There is footage from at least two HD/UHD cameras that Sky for example may already have access to show them, even though it was BT Sport showing the match.. I do agree that it is initially insects on the CCTV but the other footage will confirm from there on. They may have also had CCTV submitted to them but not decided to publish it due to its nature (ie clearer and more shocking). The CCTV footage was only shown by the big stations due to the Sun doing so.. disgracefully. However it does allow us to rule things out so for us it isn't a bad thing.
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It has been a few years since I flew heavy helicopters but fundamentally the loss of TR control 200-500 feet above the stadium was not survivable.
The AAIB will want to quickly establish the '4 corners' of the accident to confirm that all the components of the aircraft are present at the crash scene. One video shot seems to suggest that a component flew away from the aircraft with high energy immediately before control was lost, the only components posessing such energy would have been a MR pocket (or two) or a TR blade. The fact that the aircraft immediately lost yaw control indicates it may have been a TR blade.... Crash site pictures indicate 2 TR blades present but one is half missing, you could argue it had been consumed in the post crash fire but the edges appear jagged as if it had been torn apart rather than burnt. The AW 169 has an impeccable safety record with no history of TR blade mishaps or other TR drive or contol problems. So why in this case?
TR blades are stressed in construction so as to survive a minor impact from a birdstrike and still perform their role. In this day and age modern helicopters do not crash because birds fly through the tail rotors. In-service failure due to substandard manufacturing is a possibility but frankly unlikely. It is much more likely that a foreign object struck the tailrotor causing sufficient damage to cause blade failure and separation.... But caused by what? The surrounding area several hundred yards in every direction will be thoroughly searched for debris.... who knows what else might be found?
Might we be looking at the first fatal aviation accident due to an aircraft colliding with a drone?
The AAIB will want to quickly establish the '4 corners' of the accident to confirm that all the components of the aircraft are present at the crash scene. One video shot seems to suggest that a component flew away from the aircraft with high energy immediately before control was lost, the only components posessing such energy would have been a MR pocket (or two) or a TR blade. The fact that the aircraft immediately lost yaw control indicates it may have been a TR blade.... Crash site pictures indicate 2 TR blades present but one is half missing, you could argue it had been consumed in the post crash fire but the edges appear jagged as if it had been torn apart rather than burnt. The AW 169 has an impeccable safety record with no history of TR blade mishaps or other TR drive or contol problems. So why in this case?
TR blades are stressed in construction so as to survive a minor impact from a birdstrike and still perform their role. In this day and age modern helicopters do not crash because birds fly through the tail rotors. In-service failure due to substandard manufacturing is a possibility but frankly unlikely. It is much more likely that a foreign object struck the tailrotor causing sufficient damage to cause blade failure and separation.... But caused by what? The surrounding area several hundred yards in every direction will be thoroughly searched for debris.... who knows what else might be found?
Might we be looking at the first fatal aviation accident due to an aircraft colliding with a drone?
TDP is up to 400ft in the Variable TDP profile. Depends on the height of the obstacle.
The calculation of TDP is: TDP=Height of Obstacle + Clearance Height from Obstacle + 80 ft. Using the graphs (poorly) and not knowing the ambient conditions/weights/exact height of obstacele etc, TDP could be around 330ft. That assumes the stadium to be around 200ft high.
If TDP calculates out to be 400ft or more then you are weight restricted.
Climb rate should be less than 300ft/min on the vertical climb. So from the video you should be able to (very roughly) estimate their height above the pitch when they looked to hit TDP and pole forward.
All approximate and not to be taken as gospel!!!
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To add something to the debate-
I tried TRDS failure at 300' TDP in the AW169FFS. daytime, & knowing it was going to happen. I survived.....but only at the second attempt! Main problem was having to look inboard to get the engine mode switches , which are located significantly out of your line of sight if looking out of the windshield (using left hand, which means removing it from collective!).
I honestly think the chance of getting away with it for real, single pilot at night are pretty close to zero.
I tried TRDS failure at 300' TDP in the AW169FFS. daytime, & knowing it was going to happen. I survived.....but only at the second attempt! Main problem was having to look inboard to get the engine mode switches , which are located significantly out of your line of sight if looking out of the windshield (using left hand, which means removing it from collective!).
I honestly think the chance of getting away with it for real, single pilot at night are pretty close to zero.
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Yes, the gearboxes have "run dry" times. From memory the MGB is 53 minutes. I don't know about the IGB or TGB but they're under a lot less stress than the MGB.
As far as the "smoke/unburnt fuel" on engine start, it looks like steam to me. Had this quite a lot with 139 starts in cold weather with hot engines. Moisture would condense in the exhausts and give quite a good puff on engine start. Of course, the 169 doesn't have the monstrous exhausts of the 139!
Anyone know the critical wind quadrant/velocity for LTE????!
As far as the "smoke/unburnt fuel" on engine start, it looks like steam to me. Had this quite a lot with 139 starts in cold weather with hot engines. Moisture would condense in the exhausts and give quite a good puff on engine start. Of course, the 169 doesn't have the monstrous exhausts of the 139!
Anyone know the critical wind quadrant/velocity for LTE????!
LTE - loss of tail rotor effectiveness. Jesus! .............
From the video......it looks very much like a sudden loss of TR thrust. That’s all that should be inferred. There are numerous possible reasons for that condition........none of which can be identified from the evidence in the video.
Careful using any FFS for analyzing technique on this kind of emergency. They are not programmed for it and generally don't have the flight data anyway, so you are working off a programmer's hunch. Years ago the CAE 412 and Flightsafety 412 sims had noticeable differences to tailrotor malfunctions, corrected only after a Canadian Forces 412 that was fully wired for HUMS/FDM suffered a for real tail rotor failure and provided accurate modelling information. Looks like this accident will do the same for the 169 sim.
For all you sim jockeys, have a feel at the yaw difference between knocking the engines off and bottoming the collective. I used to do it old school with the aircraft on 212/412 and there was a substantial difference between the two that was not captured on the sim models. Same with the nose down overpitching.
For all you sim jockeys, have a feel at the yaw difference between knocking the engines off and bottoming the collective. I used to do it old school with the aircraft on 212/412 and there was a substantial difference between the two that was not captured on the sim models. Same with the nose down overpitching.
If anything - this thread has brought out some complete and utter moronic statements from so called pilots.
Goes to show either the helicopter industry is plagued with idiots or infiltrators from another planet!
Please think before you press "reply" FFS.
Christ - why should aviation tremble...................
Goes to show either the helicopter industry is plagued with idiots or infiltrators from another planet!
Please think before you press "reply" FFS.
Christ - why should aviation tremble...................
Well, the BBC's "experts" are plumbing new depths for their analysis:
https://www.bbc.co.uk/news/uk-englan...shire-46044224
Do these people, or the BBC, realise how stupid they sound?
Of tail rotor failures, Mr Rowlands says:
and
I think I speak for many here when I say: Mr Rowlands, if you want to position yourself as an expert in looking out of the side of a helicopter (Puma crewman, no?), then great. But stop talking about flying unless you have some kind of rotary wing pilot rating. Mr Bray, perhaps you should do the same.
And, BBC, you might want to redefine what an expert is, because you appear to have found two who don't even approach the standards required to be labelled as such in an aviation context. The fact that I am in some small way paying for you to spew this crap makes me sick.
https://www.bbc.co.uk/news/uk-englan...shire-46044224
Do these people, or the BBC, realise how stupid they sound?
"Mr Bray agreed: "It's normal because it's just starting up. When you start an engine up, sometimes you get some vapour or something coming out."
""He takes off, goes up and hovers above the stadium, because then he has got to assess which way the wind is coming and wind speed and everything else," said Mr Bray."
Mr Bray said a mechanical fault was also possible, but he believes this is unlikely.
"These things are checked to the nth degree and any professional pilot will want to make sure his aircraft is safe," he said.
"Obviously, they are putting their own lives at risk.
"It's very, very weird."
"These things are checked to the nth degree and any professional pilot will want to make sure his aircraft is safe," he said.
"Obviously, they are putting their own lives at risk.
"It's very, very weird."
""Thankfully, they are not the kind of things that happen often and I certainly don't have any personal first-hand experience of a real one, and I don't know anybody who does."
Mr Rowlands believes the pilot manoeuvred the aircraft to prevent loss of life to people on the ground.
"The fact that no-one else apart from people in the aircraft were injured is pretty amazing and I think that's why it's testament to the pilot," he said.
"It's quite a disorientating environment to be in and I think the pilot has done well because not only has he got control of the aircraft, but he's trying to minimise the impact of any incident."
"The fact that no-one else apart from people in the aircraft were injured is pretty amazing and I think that's why it's testament to the pilot," he said.
"It's quite a disorientating environment to be in and I think the pilot has done well because not only has he got control of the aircraft, but he's trying to minimise the impact of any incident."
And, BBC, you might want to redefine what an expert is, because you appear to have found two who don't even approach the standards required to be labelled as such in an aviation context. The fact that I am in some small way paying for you to spew this crap makes me sick.
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The mention of 'dead man's curve' by the media is not so much rubbish as is being represented above.
It you suffer a TR failure in any conventional helicopter in a normal hover then you have no option but to check down on the collective and cushion the subsequent touchdown. If you are in a hover high above the ground then your chances of a tidy touchdown diminish with height. Away from the ground the only way to stop the spinning from the anti-torque reaction is to chop both engines by simultaneously retarding both power levers and dump the collective to enter autorotation.
Unfortunately you now have another problem of sorting out the self-induced double engine failure. You now need forward airspeed of at least 40-60 knots to execute an engines-off landing. To gain that airspeed you have to pitch sharply nose-down which not only increases your rate of descent but appreciably kills some of your remaining rotor RPM which is your life blood in executing a successful EOL. The chances of a succcessful EOL from a free-air hover of between 50 and 1000 feet are negligible.... even before you consider the complication of the confined area beneath you..... that's the dead man's curve.
It you suffer a TR failure in any conventional helicopter in a normal hover then you have no option but to check down on the collective and cushion the subsequent touchdown. If you are in a hover high above the ground then your chances of a tidy touchdown diminish with height. Away from the ground the only way to stop the spinning from the anti-torque reaction is to chop both engines by simultaneously retarding both power levers and dump the collective to enter autorotation.
Unfortunately you now have another problem of sorting out the self-induced double engine failure. You now need forward airspeed of at least 40-60 knots to execute an engines-off landing. To gain that airspeed you have to pitch sharply nose-down which not only increases your rate of descent but appreciably kills some of your remaining rotor RPM which is your life blood in executing a successful EOL. The chances of a succcessful EOL from a free-air hover of between 50 and 1000 feet are negligible.... even before you consider the complication of the confined area beneath you..... that's the dead man's curve.
TC......the good news is the Idiots among us usually thin their own Herd for us!
Other way around. Collective full down first, then sort out your recovery attitude and think about your plan. There is no hurry to get the engines off if you've backed off most of the power with collective and you have height to play with. If you have airspeed the tail fin will give sufficient anti-torque against the engines at low power, just accept out of trim flight. Engines off (not idle) before flare for auto-rotation landing. It is far more important to get the collective down and re-establish a stable attitude after TR drive failure than rushing to get the engines off immediately.