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An angel at my pad (Keck hospital rooftop crash)

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An angel at my pad (Keck hospital rooftop crash)

Old 10th Nov 2020, 07:12
  #21 (permalink)  
BFM
 
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I wonder how that's going to be removed? It's a long way up. A bigger helo to lift?
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Old 10th Nov 2020, 07:41
  #22 (permalink)  

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Originally Posted by Old Farang View Post
Going by the strange (oil) mess on the helideck, this makes the most sense.
If I had been involved, that might have been wee.
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Old 10th Nov 2020, 09:45
  #23 (permalink)  
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The crashworthiness of that aircraft in the second video is quite impressive, it really did hit the heli-pad quite hard on its side which is not where the best impact cushioning for the occupants lies.

I've not flown an AW109, and like Alpha-Romeo's I don't seem to fit in them very well, but I'm told that unlike say an AS350 they are quite benign on the piano pedals through most phases of flight. Can the pedals also be operated without power assistance much like an AS350?
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Old 10th Nov 2020, 09:47
  #24 (permalink)  
 
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Originally Posted by cattletruck View Post
The crashworthiness of that aircraft in the second video is quite impressive, it really did hit the heli-pad quite hard on its side which is not where the best impact cushioning for the occupants lies.

I've not flown an AW109, and like Alpha-Romeo's I don't seem to fit in them very well, but I'm told that unlike say an AS350 they are quite benign on the piano pedals through most phases of flight. Can the pedals also be operated without power assistance much like a B206 or AS350?
Did you read Shy Torque’s post?
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Old 10th Nov 2020, 09:53
  #25 (permalink)  
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Did you read Shy Torque’s post?
Yes, just trying to compare the effort required with something I already know.
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Old 10th Nov 2020, 09:55
  #26 (permalink)  
 
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Originally Posted by ShyTorque View Post
If it wasn’t a driveshaft failure it must have been a hard right pedal input, or control runaway. It’s difficult to tell if the tail rotor rpm changed because we’re not watching in real time and camera frame rate masks what’s going on.



As per the previous post, the aircraft are totally different types (169 versus 109) and their tail rotor control systems are totally different.
Thanks to you both for the answer(s).
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Old 10th Nov 2020, 11:43
  #27 (permalink)  

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Originally Posted by cattletruck View Post
Yes, just trying to compare the effort required with something I already know.
I flew a Squirrel ‘N’ for three years or so. The hydraulics out pedal feedback forces are definitely a lot higher on the A109 and there is no accumulator, unlike that of the Squirrel.

The tail rotor blade pitch of the 109 is designed to revert to a neutral setting without hydraulics. However, to move them from that setting you have to use so much foot force on the pedals (to get limited effect) it feels like something is likely to bend or break.

The good news is that the aircraft remains flyable in most circumstances, provided that it doesn’t happen at very low speed!
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Old 10th Nov 2020, 11:54
  #28 (permalink)  
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Thanks ST, much appreciated.
Any horn (Fiat?) go off if you lose that hyd circuit?
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Old 10th Nov 2020, 12:07
  #29 (permalink)  

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Originally Posted by cattletruck View Post
Thanks ST, much appreciated.
Any horn (Fiat?) go off if you lose that hyd circuit?
No need.....the flashing master caution light and the kick in the pedals are clue enough! The horn on a Squirrel is there because the hydraulic accumulator gives you a few seconds to sort your life out.

The RFM advice for the 109 advises a slow reduction to 90kts and not using any AOB greater than 25*. It also warns against flight regimes needing high control inputs.....

If this is what happened here, it just wasn’t the pilot’s day. At least they all escaped major injury, or worse.

Last edited by ShyTorque; 10th Nov 2020 at 17:03. Reason: Slight change to clarify AOB advice.
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Old 10th Nov 2020, 16:06
  #30 (permalink)  
 
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The #1 Hyd fail approaching the hover is something I regularly train on the A109 FFS. It is controllable, but you have to recognise it quickly, and give it a seriously hard load of left boot. If it takes you by surprise, it could easily give you a rapid right yaw before you can react.
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Old 11th Nov 2020, 08:05
  #31 (permalink)  
 
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Given the modest amount of damage to the aircraft, and that there were no injuries, the basic cause of this surely has to be known by now. Particularly for those of us that fly 109s, the most important thing is having this info asap so at least we/maintenance can know if there is anything that needs extra attention. Thankfully mechanical failures are very rare, but, if it was one, this could easily have had been an accident of as much tragedy and sensation as the Leicester 169.
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Old 12th Nov 2020, 05:17
  #32 (permalink)  
 
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Originally Posted by ShyTorque View Post
Having carried out a ‘Check A’ on the 109 every working day for the last decade and a half and having over 3,000 hours on type, I do have some idea of how the thing is put together.

One other “gotcha” on this type is that out of the two hydraulic systems, only #1 boosts the yaw servo. If #1 hydraulics drop off line, servo assistance is lost and the pedal feedback forces can be very high. It’s then very difficult to apply enough “boot” to keep the aircraft straight at low speed. The normal way to land in that condition is a running landing at about 30 kts, ideally with a crosswind from the left.
You have me by 2 years. I only have 8 years on the 109/119 series. As a licenced mechanic doing line and heavy maintenance. It's a pretty basic and very reliable TR system. The TR itself however is a maintenance hog with the Teflon bushings wearing out pretty quick depending on how many cycles/hour you do. Keep it shimmed and keep it tight and it will last. Unlike a Bell, the TR should NOT teeter easily on the trunnion. It should take a good push with the palm of your hand. A TR that teeters like a Bell is worn out and is probably going to cost you many $$$ to sort out.
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Old 12th Nov 2020, 07:59
  #33 (permalink)  

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Nooby, two years? You missed out the other half decade but I’m always grateful for an engineering point of view.
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Old 16th Nov 2020, 20:49
  #34 (permalink)  
 
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Originally Posted by ShyTorque View Post
Nooby, two years? You missed out the other half decade but I’m always grateful for an engineering point of view.
I wasn't including drinking days. LOL.

Normally if Leo is concerned about the aircraft they would have communicated as such by now. But it is still silence. Which would SEEM to indicate that all was well with the aircraft, or at least that it wasn't a design/manufacturing defect.
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Old 21st Feb 2021, 19:31
  #35 (permalink)  
 
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Did NTSB issue any report on this accident?
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Old 21st Feb 2021, 20:32
  #36 (permalink)  
 
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Originally Posted by gmrwiz View Post
Did NTSB issue any report on this accident?
Googling show there's an initial factual one - http://data.ntsb.gov/carol-repgen/ap...ort/102246/pdf

Nothing further.
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