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Helicopter down outside Leicester City Football Club

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Helicopter down outside Leicester City Football Club

Old 4th Nov 2018, 17:54
  #561 (permalink)  
 
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I completely understand that the procedure was 'within the defined and certified operational envelope' - my question was whether or not it was 'normal' in terms of how others had observed this and similar aircraft taking off from this location in similar circumstances before. Equally, I didn't mean to suggest that - even if the procedure was 'abnormal' in those terms, it was the cause of the accident.
I was really wondering if there could have been a perceived anomaly in the performance/response or any other aspect of the aircraft (that we can't see) that might have lead to the pilot wanting to gain more height that 'normal' and that, if so, whether this might give any clues as to what subsequently caused the apparent catastrophic failure (that we can see).
The only 169 profile suitable to this stadium which factors obstacle clearance is the variable TDP helipad. The TDP is 115ft + the height of the obstacle in your takeoff path so Iíd guess a minimum of 250-300ft. The single engine failure before TDP is a not an overly Ďdynamicí manoeuvre unlike some types. You need good references through the chin window and you fly back down the same path with up to 192% TQ available.
TDP - is just that, a "decision point", before it you come back down after it you can fly away and achieve the MINIMUM clearance to obstacles. If you continue climbing about the only thing that changes is the obstacle clearance gets larger.

So what?
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Old 4th Nov 2018, 17:59
  #562 (permalink)  
 
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Countless times trying to get out of a tight spot in the boonies, back it up as far as you can go, get some airspeed whilst still in ground effect and then zoom climb it out at best angle. Many of those you'd never get out vertically, you just run out of puff before finding clear air above the trees.
seen this technique advocated by the Aussie mil but it leaves you very poorly placed in the event of an engine failure since you are travelling too fast to stop before you rotate and have nowhere to go once you have rotated
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Old 4th Nov 2018, 19:01
  #563 (permalink)  
 
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Cables near statium

There are 100 foot towers with cables to the north and east of the stadium. the stadium is in blue, centre background.
Would this influence departure planning?

According to Google Earth's radar the stadium flat roof is 19m above the pitch.

https://goo.gl/maps/ZLNQyosngDu



Leicester City Football ground - in blue.
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Old 4th Nov 2018, 20:58
  #564 (permalink)  
 
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Originally Posted by chopjock View Post
Tc


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.
check post 562, engines fail more often than tailrotors.
And I ˋm not talking engine chips, had actually parts of the compressor going through the engine, a friend a loose generator smashing the engine bay, but no tailrotor related issues so far....
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Old 4th Nov 2018, 21:08
  #565 (permalink)  
 
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Originally Posted by Sir Niall Dementia View Post
And for those who doubt a goose could down a helicopter, how about the Blackhawk in January 2014 in Cley, Norfolk, UK, But I really don't believe either geeese, mute swans or anything else at the moment.

SND
Not sure I get the significance of this reference to this case. The Pave Hawk crash was caused by flying into a flock of geese, "at least three of which penetrated the cockpit glazing, and which rendered the flight deck crew unconscious".
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Old 4th Nov 2018, 21:54
  #566 (permalink)  
 
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I can't decide whether it's the alien insects, white swans, black swans, ghosted black trash bags, capitalist friendly communist saboteurs, monkey wrenching ghosts escaping the tailpipe right before our very eyes. Or if it's just plain old 'built on a Friday afternoon' to the irresistible call of the 'dolce vita' that is the root cause of this unfortunate event.

I know the 'old hands' here, know the hopelessness of the situation but I would like to address those with 'Walter Mitty' ideas of an ideal outcome to the scenario. Seeing as the manufacturers with their relatively bottomless time and intellectual resources haven't been able to accurately model yaw rate outcomes in the simulator. I wouldn't fault this fellow for overestimating his keel surface area while in the midst of a mortal split second decision in which the other option (while yaw free) looks like the drop of doom.

It's a classic crew room argument regarding autorotation deep within the vertical part of the HV curve, you have your nose diver/lawn dart school versus your saner and more conservative,keep the disc mostly level , 'bottom and pull ' school. The nose divers reassure themselves of their superiority by getting away with preplanned and pre rehearsed practice autos in the shady portions of the curve. It's a high risk gamble that doesn't allow time for any necessary thought or hesitation when the real thing happens. Much helped with a significant headwind and a field free of obstructions. I am going to cast this option out as pure 'holeshot' fantasy. ROD building to free fall speeds with insufficient height and airspeed to carve a proper flare trajectory..= lawn dart. Though Walter Mitty would have the panache to plant it across 'the away teams' goal line. Leaving us with the 'parachute' option.

It's an oft repeated statement in rotorcraft engineering textbooks that steady state vertical autorotation rates are very close to, if not a little greater, than what a parachute with an effective diameter equal to that of the rotor disc would yield. Knowing this we can build an idea of what the ideal 'bottom and pull' reaction is going to look like.

You can spare yourself the freshman physics headache by using the modern miracle of the internet, to enlist the help of a physics engine to calculate free fall with air resistance. https://www.omnicalculator.com/physi...air-resistance. Go to advanced settings, set your coefficient of drag to 1(flat plat area) ,enter disc area and approx weight, height,air density is obtained within the sites database itself. Lock those parameters in. I've got that AW169 coming to pitch pull height with round about 55 mph of vertical velocity. (Equal to the cab dropped free fall by a crane at 100 feet) Sure the pitch pull might scrub 5 even 10 mph off, it's somewhat of a bone of contention. The real studious among us will figure this out by the height at which hover chop exercises can arrest the descent rate to zero.

It's nothing but ugly......but may encourage respect for the curve...or a change of profession. Paratroopers eat your heart out, Robinson drivers don't subtract anything for the pitch pull....

I don't pretend aspiring billionaires are safe in anything flown at this profile but would offer a shameless plug for a restricted weight ,modernized 212 or 214st. Beautiful Americana. Leave the martinis till the after party. Laughable as VIP ships but likely still the most favourable autorotation index of anything out there "off the shelf"


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Old 4th Nov 2018, 22:04
  #567 (permalink)  
 
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Washed, Very Well said!


Karl,

The S-76 was at cruise speed when it collided with a large Red Tailed Hawk which shoved the Engine Lever Quadrant rearwards after shoving the Windscreen upper frame rearwards.
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Old 4th Nov 2018, 22:08
  #568 (permalink)  
 
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Originally Posted by Sir Niall Dementia View Post
And for those who doubt a goose could down a helicopter, how about the Blackhawk in January 2014 in Cley, Norfolk, UK, But I really don't believe either geeese, mute swans or anything else at the moment.
SND
Re Birdstrikes a good few years back I did some extensive studies and stats analysis on bird strikes for a FW commercial airline.
Most strikes high 90%'s occurred in daylight/twilight hours, night strikes were very rare.
If I recall the numbers correctly, most impacts likely 2/3rds were beneath 3-400ft height.
I can't recall any reports of a strike that wasn't some form of head on collision, be it airframe/nose/screen/leading edges, engines and ingestions into engines.

Assuming a direct tail rotor strike, I'd be very surprised if a bird (singular) faced with a relatively slowly manoeuvring helicopter in its path, anticols flashing, high noise and downdrafts etc didn't take its own avoiding action, i.e turn away from the helicopter, as most species do react negatively to various forms of pyrotechnics and noise.
I'd anticipate a hovering, or slow moving helicopter to be producing enough downward turbulence and rotor wash to potentially protect it from a bird strike?
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Old 4th Nov 2018, 22:09
  #569 (permalink)  
 
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Originally Posted by Washeduprotorgypsy View Post
...offer a shameless plug for a restricted weight ,modernized 212 or 214st. Beautiful Americana...


Beautiful indeed, and sounds even more beautifuller.
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Old 4th Nov 2018, 22:28
  #570 (permalink)  
 
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A Billionaire VIP Helicopter.....a Bell 212?

Only if the Boss Fellah likes his Martini shaken and not stirred!
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Old 4th Nov 2018, 22:36
  #571 (permalink)  
 
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Originally Posted by jumpseater View Post
Re Birdstrikes a good few years back I did some extensive studies and stats analysis on bird strikes for a FW commercial airline.
Most strikes high 90%'s occurred in daylight/twilight hours, night strikes were very rare.
If I recall the numbers correctly, most impacts likely 2/3rds were beneath 3-400ft height.
I can't recall any reports of a strike that wasn't some form of head on collision, be it airframe/nose/screen/leading edges, engines and ingestions into engines.

Assuming a direct tail rotor strike, I'd be very surprised if a bird (singular) faced with a relatively slowly manoeuvring helicopter in its path, anticols flashing, high noise and downdrafts etc didn't take its own avoiding action, i.e turn away from the helicopter, as most species do react negatively to various forms of pyrotechnics and noise.
I'd anticipate a hovering, or slow moving helicopter to be producing enough downward turbulence and rotor wash to potentially protect it from a bird strike?

Unfortunately birds don't read Rotorheads and the tales of birdstrikes in just those conditions are legion. Mine include an albatross flying into the main rotor of a Sea King running on deck, Spot 5, HMS Ark Royal, ready for takeoff with the ship steaming at 15kts. Another was hover taxiing out in a 412 at an airport, and so on.


The premise in this accident has a likelihood somewhere between nil and -10, as the remains would easily have been visible on the TR blade(s) and identified early in the investigation. Returning to discuss a birdstrike on the TR is just wasting bandwidth, IMO.
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Old 5th Nov 2018, 10:38
  #572 (permalink)  
 
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Brother Eacott has made a statement of fact that I fully endorse.


Returning to discuss a birdstrike on the TR is just wasting bandwidth, IMO.

Let's move on to yet another silly notion shall we?
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Old 5th Nov 2018, 10:48
  #573 (permalink)  
 
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SAS I agree 99%. I leave 1% open in case AAIB find twas a bird that did it!
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Old 5th Nov 2018, 10:55
  #574 (permalink)  
 
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Type of Departure

FW Pilot here.

Perhaps the the type of departure chosen was precisely because there was a good chance it would be filmed being as they were departing the scene of a Premiership footy match. I think if the eyes of the world were on you, you would conform with the procedures in the book to prevent a polite request to come to Gatwick and explain why you didnít do it by the book, should that type of footage become available to the chaps down there.

That might explain why one option was chosen as opposed to another? Not sure.

Iíve learnt a lot reading this thread. Thanks for education. Apologies for chipping in if the above is irrelevant.
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Old 5th Nov 2018, 10:58
  #575 (permalink)  
 
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I have lost track of all the fanciful notions that have been put forth.....not withstanding the amount of video available for viewing that should be a decent starting point for discussion.

Of late....it has been like playing Cricket in a Corn field....it is very hard to keep one's eyes on the Ball.
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Old 5th Nov 2018, 11:07
  #576 (permalink)  
 
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604 Driver, for the most part, professional helicopter pilots follow the rules and procedures. Regardless of who's watching or otherwise. The departure flown looked to me like the optimum solution for obstacle environment he was operating in. Although it would seem very strange to a fixed wing man or even a SEH pilot, moving upwards and backwards has been a feature of VTOL Helipad Profiles in almost all modern MEHs. I did not know the pilot but friends have posted here and he would seem a very competent careful man. Majority of professional helicopter pilots posting here will agree that when faced with such a departure, an extra level of care is taken to try an fly the profile accurately. Mostly because we are always exposed to these profiles in the FSTD with OEI events. The video certainly supports a very careful, well flown departure until whatever happened in the latter stages of the initial climb.
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Old 5th Nov 2018, 11:23
  #577 (permalink)  
 
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Thanks DB.

I should have mentioned Towering Departure Viz a Vis the back up as opposed to not following regs 👍 but thanks for taking the time there.

Eric was regarded very highly in the FW world. Iím sure thatís the case in the RW too.
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Old 5th Nov 2018, 11:58
  #578 (permalink)  
 
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It seems the Aw169 was grounded by Leonardo due to "tail rotor shaft problem".
Anyone can confirm this rumor?
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Old 5th Nov 2018, 13:11
  #579 (permalink)  
 
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Originally Posted by aegir View Post
It seems the Aw169 was grounded by Leonardo due to "tail rotor shaft problem".
Anyone can confirm this rumor?
Could this be the source of the rumor?
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Old 5th Nov 2018, 13:37
  #580 (permalink)  
 
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No my rumors came from EMS world.
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