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Helicopter down outside Leicester City Football Club

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Helicopter down outside Leicester City Football Club

Old 3rd Nov 2018, 09:55
  #521 (permalink)  
 
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All the AW 1*9 family have puller TR on the right hand side and all have MR rotation anti-clockwise when viewed from above.
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Old 3rd Nov 2018, 10:41
  #522 (permalink)  
 
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Simple question for my betters:

Would a lift into a low hover transitioning into a more 'horizontal' take off be inherently safer than a departure like this one? (Given a suitable obstacle free 'runway'/take off path....)

And would a suitable take off run have been available outside the stadium?
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Old 3rd Nov 2018, 10:44
  #523 (permalink)  
 
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Originally Posted by Mitchaa View Post

Vortex ring wouldn't cause that effect, it would just simply plummet.
VR may not cause that effect, but if in VR with no TR drive I'm sure it would rotate. I should think this incident could well have entered VR on the way down without tail rotor drive. It had a high ROD and drifted down wind. We don't know about the power setting yet...
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Old 3rd Nov 2018, 10:58
  #524 (permalink)  

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Originally Posted by Jackonicko View Post
Simple question for my betters:

Would a lift into a low hover transitioning into a more 'horizontal' take off be inherently safer than a departure like this one? (Given a suitable obstacle free 'runway'/take off path....)

And would a suitable take off run have been available outside the stadium?
What do you mean by "inherently safer"? If the t/r drive was faulty (if that is what caused this, hopefully initial findings will soon be made public) the accident might have occurred at a slightly different time but would possibly have put the aircraft down in a less fortunate place for those on the ground. Helicopters are designed to operate vertically, btw! The departure flown appears to have followed a certified Category A / Class 1 profile so it should have been as safe as any other.
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Old 3rd Nov 2018, 11:09
  #525 (permalink)  
 
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Does anyone have a schematic of the tail rotor driveshaft and gearbox assemblies?
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Old 3rd Nov 2018, 13:29
  #526 (permalink)  
 
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Originally Posted by ShyTorque View Post
What do you mean by "inherently safer"? If the t/r drive was faulty (if that is what caused this, hopefully initial findings will soon be made public) the accident might have occurred at a slightly different time but would possibly have put the aircraft down in a less fortunate place for those on the ground. Helicopters are designed to operate vertically, btw! The departure flown appears to have followed a certified Category A / Class 1 profile so it should have been as safe as any other.
Presumably he means that had the climb out been more forwards, gaining airspeed, translational lift and a headwind asap there would be less stress on the TR and for a shorter exposure time...
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Old 3rd Nov 2018, 13:38
  #527 (permalink)  
 
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The 169 has a winching capability. That punishes the tail rotor far more than a Cat A departure.
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Old 3rd Nov 2018, 14:48
  #528 (permalink)  
 
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Chopjock.

You'll never change will you? After years of posting on rotorheads, listening to the advice of others - you still talk complete and utter bo**ox, don't you?
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Old 3rd Nov 2018, 17:38
  #529 (permalink)  
 
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TC

Sorry Chopjock is correct, if you actually care to read the post Chop was referring to you will find Chop's answer is strictly correct. Unless you would prefer to be at 400 ft with no forward airspeed when the Tr assy takes a holiday. Personally I would take lower and probably doing around 60 to 80 kts ( that he would have arrived at in the time to go vertical to 400 ft.) At least your stabilisers would be doing something.
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Old 3rd Nov 2018, 17:53
  #530 (permalink)  
 
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A question for you Legal Scholars posing as Helicopter Pilots.....the British way of doing a Confined Area Takeoff (I learned it as a Towering Takeoff) differed from the American way of doing the same thing (each used the same power) is far different from the various CAT A, Perf Class One (or whatever you are calling things this week).

Instead of this backwards and up to 400 feet (or so) as we saw used.....what if an old fashioned Towering Take Off had been used from as far downwind as possible and the aircraft accelerate much lower but clear of obstacles.....could Vtoss and Vbroc been achieved much quicker?

What Rules, Regulations, etc.....prohibit such a Takeoff like that a situation as is under discussion?

Are Rules getting ahead of reality and causing greater risk instead of making flying safer?
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Old 3rd Nov 2018, 18:09
  #531 (permalink)  
 
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Originally Posted by [email protected] View Post
All the AW 1*9 family have puller TR on the right hand side and all have MR rotation anti-clockwise when viewed from above.
Except for the 109 and 119, which push
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Old 3rd Nov 2018, 18:12
  #532 (permalink)  
 
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Originally Posted by SASless View Post
A question for you Legal Scholars posing as Helicopter Pilots.....the British way of doing a Confined Area Takeoff (I learned it as a Towering Takeoff) differed from the American way of doing the same thing (each used the same power) is far different from the various CAT A, Perf Class One (or whatever you are calling things this week).

Instead of this backwards and up to 400 feet (or so) as we saw used.....what if an old fashioned Towering Take Off had been used from as far downwind as possible and the aircraft accelerate much lower but clear of obstacles.....could Vtoss and Vbroc been achieved much quicker?

What Rules, Regulations, etc.....prohibit such a Takeoff like that a situation as is under discussion?

Are Rules getting ahead of reality and causing greater risk instead of making flying safer?
I must admit that during my time with Army flying, I was always a little puzzled watching civil helicopters performing all sorts of convoluted and painfully slow departures when we just took off into wind and transitioned as quickly as possible, then along the years we started to introduce committed calls at various airspeed and heights in twins. Leaving the military and starting police and corporate flying introduced a whole section of the flight manual to be observed depending on aircraft weight, helipad size, obstructions,....etc. Explaining to passengers why I was not just flying forward became part of the pre take of drills at one particular base, just to head off the inevitable question halfway up to TDP!
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Old 3rd Nov 2018, 18:15
  #533 (permalink)  
 
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SASless, it is a cart/horse question on regulation/performance profiles and which comes first. There are lots of risks and hazards in helicopter flying only some of which are addressed by regulation. And those tend to be the quantifiable ones. Easiest is the airline model where the worst that can happen is an engine failure, and so that is then applied to helicopter and the regulators come up with different standards, exposures, etc. Some, like EASA, have more focus on compliance to OEM flight test certification procedures than others. In our Wild West view of confined, the greatest risk is hitting something, in the EASA view or PC1, it is the first engine failing (the second one never fails). So the certification authorities go back to the manufacturers and say "give us the numbers and performance charts, and publish them in the RFM". Now over to sales where performance sells, so the manufacturer uses their test pilots to develop OEM recommended procedures to maximize performance and payload, regardless of the real-world additional risks introduced. Two examples: the back up profile in a true "confined" area where you might actually hit something; some of the PC1 runway takeoffs where the TDP is an altitude instead of an airspeed. When I first flew S76, the PC1 takeoff profile was like a "cobra" maneuver, accelerate to a certain speed, balloon up and level, accelerate some more and then climb - just the thing not to do on a black night in monsoon rain with a new national copilot.
Anyway, a horse beat to death, and there are many on this forum (such as JimL) that can explain it much more clearly than I can. Needless to say, in todays world nobody will risk any SOP other than the OEM provided one, to the point that even where there are obvious flaws operationally, like the original AW139 offshore helideck with the too rapid climb through 20', we will fly a far riskier profile until the OEM can come up with a published revised profile. And yes, in the past we had free rein to make those up and apply them ourselves.
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Old 3rd Nov 2018, 18:38
  #534 (permalink)  
 
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Except for the 109 and 119, which push
good point bosbefok - I was just thinking of the 139, 169 and 189 and forgot about the 109 and 119
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Old 3rd Nov 2018, 18:57
  #535 (permalink)  
 
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Originally Posted by Thomas coupling View Post
Chopjock.
You'll never change will you? After years of posting on rotorheads, listening to the advice of others - you still talk complete and utter bo**ox, don't you?
Hmm, I'm not sure I quite understand what exactly is b*****ks with @Chopjocks remark? Reducing the time spent at zero forward speed will reduce the time spent in very unhelpful conditions when encountering a TR drive failure. Any forward speed will unload the TR, thereby reducing torque effect and will additionally increase effectiveness of the fin. At >50kts there is a reasonable fighting chance in case of a TR drive failure. At zero kts not so much.
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Old 3rd Nov 2018, 19:11
  #536 (permalink)  
 
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Reducing the time spent at zero forward speed will reduce the time spent in very unhelpful conditions when encountering a TR drive failure. Any forward speed will unload the TR, thereby reducing torque effect and will additionally increase effectiveness of the fin. At >50kts there is a reasonable fighting chance in case of a TR drive failure.
And maybe not?

In the current designs with very small vertical surfaces be aware they virtually have no fin or it is very weak in effect -

Phoinix
8th Dec 2015, 13:16
I just finished my recurrent on the 412 at DFW South location. It's a brand new sim capable of 412EP with EFIS, Fast Fin and 4 axis AP. Extremely detailed visuals and updated flight data. The later was a huge surprise.

The instructor gave us a tail rotor drive shaft failure... Surprise surprise, the 412 is not capable of flight at any speed, Fast fin or not. If you enter an autorotation fast enough your only option is to follow it through the right turn, flaring at about 100-ish ft and of course than the left yaw comes that will turn you about 90ļ. So the flyaway no longer possible they teach to auto immediately and follow it through the right yaw.

I was on the old 212 sim and slightly newer 412 sim some years ago and I remember you could clearly fly away at a low power setting at vy.
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Old 3rd Nov 2018, 20:53
  #537 (permalink)  
 
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It is now exactly a week since the accident happened. Short of brief statements by the AAIB telling people what they already knew, there has been what can only be described as a deafening silence with regard to the cause. Would we be correct in thinking that, due to zero statements regarding the mechanical causes of this tragic accident, it can be assumed that the aircraft didnít suffer a mechanical malfunction ? Or is this normal to have no word, even if it was found to be say a mechanical defect ? Obviously Iím not saying it was, but I seem to recall in previous events, that a failure of a particular item on an aircraft would render that type grounded until further investigation could rule it out. By not having any AD or SB issued, is it fair to say that the AW 169 has not suffered a catastrophic mechanical failure, but the cause is more likely to be external forces of some description, (drone strike) or pilot error? (I doubt itís pilot error but that we have no details whatsoever yet)
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Old 3rd Nov 2018, 21:16
  #538 (permalink)  
 
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Why is anyone quizzing the CAT A departure? In commercial ops it is a requirement not an option. So debating whether a takeoff profile other than this, is better - is a load of Bo**ox.

The pilot initiated a standard departure for the size of the site.

The probable causes now remain:
Part of the TR assembly failed and departed flight.
Something struck the tail area causing a catastrophic failure.

Once an aircraft enters a developed TR failure flight path (rotating) NOTHING the pilot does to recover (with the cyclic) will resolve the issue simply because the pitch/roll datums continuously change [as described earlier very succinctly].
The suggestion that the pilot fought to steer clear of people or property is wishful thinking At this stage in the flight, the pilot(s) became a passenger.
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Old 3rd Nov 2018, 21:54
  #539 (permalink)  
 
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Originally Posted by helimutt View Post
It is now exactly a week since the accident happened. Short of brief statements by the AAIB telling people what they already knew, there has been what can only be described as a deafening silence with regard to the cause. Would we be correct in thinking that, due to zero statements regarding the mechanical causes of this tragic accident, it can be assumed that the aircraft didn’t suffer a mechanical malfunction ? Or is this normal to have no word, even if it was found to be say a mechanical defect ? Obviously I’m not saying it was, but I seem to recall in previous events, that a failure of a particular item on an aircraft would render that type grounded until further investigation could rule it out. By not having any AD or SB issued, is it fair to say that the AW 169 has not suffered a catastrophic mechanical failure, but the cause is more likely to be external forces of some description, (drone strike) or pilot error? (I doubt it’s pilot error but that we have no details whatsoever yet)

It's actually pretty rare to ground all examples of a type without some pretty solid evidence there have been multiple failures in the same mode across at least two incidents. The wreckage only departed the scene yesterday and the FDR could (par example) indicate TR performance loss without an immediate and obvious cause without further forensics.
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Old 3rd Nov 2018, 23:16
  #540 (permalink)  
 
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Tc
Why is anyone quizzing the CAT A departure?
I'm questioning it because it didn't work very well here did it? Cat A PC1 is so focused on one of two engines failing it completely disregards the extra exposure to the one and only tail rotor.
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