Apache ground scrape.
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The heli however may require a bit more work.
but it seems to me that he entered vortex ringstate
Red On, Green On
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A rotary mate used to get the odd funny look when wearing his special tie in the Wardroom at CU (as a Middy). He'd been on a pre-join acquaint and the Wasp pilot took him for a jolly. A wingover went wrong and they had to swim for it. And he still joined 
T W A T. That's better. Yep looks high up, initial climb 'mushed' due to high density alt, that set up simply set the scene for the rest. They were all very lucky that no one got badly hurt.
We don't send Pilots like these to Leavenworth....there is a far worse place.....Fort Rucker Alabama....and make Standards Evaluation Pilots out of them....if they are Warrant Officers. If they are Commissoned Officers they make General and really get to show their hind ends!
What's the fuss about....it was only an Apache....we got a thousand of the things on the shelf!
It is not like it was one of the Rupert's doing this!
What's the fuss about....it was only an Apache....we got a thousand of the things on the shelf!
It is not like it was one of the Rupert's doing this!
Serious question here - the aerodynamic reason for the crash was likely - approach at too high a rate of decent - enter into vortex ring state (essentially churning up the air so much with the rotors that there's nothing solid enough for them to bite into, to develop the lift needed to remain airborne?) - end result, aircraft falls like stone?
VRS being the helicopter equivalent of a fixed wing fully developed aerodynamic stall?
VRS being the helicopter equivalent of a fixed wing fully developed aerodynamic stall?
Gentleman Aviator
Serious answer tartare - no - more geographical than aerodynamic. For many reasons - some quoted above - the manoeuvre as flown would have taken x feet to recover.
Aircraft is at <x feet - result: misery!
Aircraft is at <x feet - result: misery!
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tartare,
To enter vortex ring you need, in general overview, three conditions. Low airspeed relative to the current wind/flight path, rate of descent and pulling power.
As you state 'churning up the air' involves inducing such a return flow from the rotor tip votice that energised air returns to the top of the disc and enters the disc in an accelerated state thus aerodynamically reducing the angle of attack of the blade as your 'induced flow' is degraded by previously accelerated air. Therefore requiring more and more pitch to reduce the rate of descent. This leads to increased votices at the tips, increased vertical downward inflow which leads to reduced aerodymanic angle of attack which leads to stall.
The mupppet in the cockpit of the Apache attempted a wing over to approach manouevre at what looks to be a relatively high altitude base. Obviously taking an assumption or two (DA and gross weight) what he did have was still air and, judging by the distance the beast travelled across the snow, relatively high airspeed in a descent profile that would have kept the helo well out of it's own rotor down wash.
Vortex ring? Very, very unlikely.
Having flown in Arctic and Antarctic areas what I see as more likely, even though it is sunny and not flat light, is a lack of depth perception to a flat white monotone surface leading to 'ground rush' and the 'O F**k' state.
Snow field operations have inherent dangers of their own!
To enter vortex ring you need, in general overview, three conditions. Low airspeed relative to the current wind/flight path, rate of descent and pulling power.
As you state 'churning up the air' involves inducing such a return flow from the rotor tip votice that energised air returns to the top of the disc and enters the disc in an accelerated state thus aerodynamically reducing the angle of attack of the blade as your 'induced flow' is degraded by previously accelerated air. Therefore requiring more and more pitch to reduce the rate of descent. This leads to increased votices at the tips, increased vertical downward inflow which leads to reduced aerodymanic angle of attack which leads to stall.
The mupppet in the cockpit of the Apache attempted a wing over to approach manouevre at what looks to be a relatively high altitude base. Obviously taking an assumption or two (DA and gross weight) what he did have was still air and, judging by the distance the beast travelled across the snow, relatively high airspeed in a descent profile that would have kept the helo well out of it's own rotor down wash.
Vortex ring? Very, very unlikely.
Having flown in Arctic and Antarctic areas what I see as more likely, even though it is sunny and not flat light, is a lack of depth perception to a flat white monotone surface leading to 'ground rush' and the 'O F**k' state.
Snow field operations have inherent dangers of their own!
Last edited by Wirbelsturm; 22nd Mar 2012 at 10:31.
Lots of stuff to see....tents, people, structures, rock out croppings.....what I see is a lot of "What If'ing" by folks that don't know squat about what really happened! The ones that do know something are not being listened to by those who only think they know something.
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Lots of stuff to see....tents, people, structures, rock out croppings
Whats hindsight obvious often isn't obvious at the time and, if it isn't CGI, the fly boy would be potentially under the influence of tunnel vision at this point.
Irrespective, a poorly planned manouvre from the outset.
(The Lynx pilot survived only because the observer had clipped a cargo lash to the harness guide hoop on the top of the Lynx seat to stop it flapping about! Lucky boy)
Wirbelsturm (4500hrs rotary)
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I'm not too familiar with the Apache variants but isn't this an older variant (ie not Longbow). Who flies this variant today? Netherlands?
Or is the video old or as stated fake ?
BW
Or is the video old or as stated fake ?
BW
Red On, Green On
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I hope it is for real or ABC News is going to look pretty silly... Their breaking news report is on the front page of Yahoo! right now...
Link
Link
"A spokesperson for the U.S.-led International Security Assistance Force told ABC News the video was taken Feb. 6 in the Paktika province in Afghanistan. Remarkably, no one on the ground was injured and the aircrew survived, the spokesperson said.
There was no enemy activity in the area and Army is currently investigating the incident, he said."
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I'm not too familiar with the Apache variants but isn't this an older variant (ie not Longbow). Who flies this variant today? Netherlands?
Or is the video old or as stated fake ?
Or is the video old or as stated fake ?
For what its worth, the Daily Wail and Mirror are also running with this story on their web sites. I think its fair to say the video's authenticity has been verified, in current newspeak.
Anyway, back to the PPRuNe B of I. I think the ground was clearly at fault in this accident, recklessly rushing upwards at that poor, unsuspecting helicopter.
Anyway, back to the PPRuNe B of I. I think the ground was clearly at fault in this accident, recklessly rushing upwards at that poor, unsuspecting helicopter.
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It's an AH-64D, as you can see from the extended EFABS. The US and Netherlands don't fly their Deltas with the Longbow installed in Afghanistan, the UK do.
BW
Do a Hover - it avoids G
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Eclan
The rotor disk doesn't bend at all in the impact. Wouldn't the rotors have drooped down and severed the boom in the impact?
In a real case you can be sure that he would have as much RPM and pitch on as he could muster.