If you never saw this you won't believe it. All survived including the guy in the basket.

I couldn't hear the audio. Did the flight crew say anything about winds. He had power to hover out of ground effect over the ridge. Problem came when he hovered away from the ridge, possibly below the declination line. Once he was settling with power, drifting backwards and down the ridge, things got too interesting.
The only cure for settling with power, with the left anti-torque petal on the stop, is to reduce collective. He evidently did that, and dipped the nose a bit. He crashed well, wiping out the main rotor blades quickly. Missile damage, things flying around, is the real danger is helicopter crashes.

I couldn't hear the audio. Did the flight crew say anything about winds.

The narrator says "Just as the air crew is about to hoist the third survivor the wind shifts and the chopper loses altitude in the thin air..." something like that anyhow. He says the elevation is 11,000 feet.

Question for the chopper pilots?
I was a kid on a Forest Service helitack crew...over 40 some years ago...there were 4 of us with all our firefighting gear in a Hughes 500 C model. Landing on a 6000 foot elevation plateau on a hot day. At about 50 feet above the ground the helicopter started to yaw back and forth, the engine suddenly got real quiet and we just floated down and landed light as a feather.

Someone said "What just happened"? The pilot...a young Viet Nam vet... replied, "We just lost one of our variables". As I remember his explanation...the tail rotor lost effectiveness and to stop the spin he reduced the throttle to idle. I think he called it a "Touch down autorotation."

Would that technique have done the guys in the Mount Hood video any good?

Would that technique have done the guys in the Mount Hood video any good.

Probably not, due to the steepness of the terrain.

Considering that a bunch of people fell off a mountain and a helicopter crashed all I can say is "Holy crap did a lot of stuff go right!"

SkySteve wrote:

Would that technique have done the guys in the Mount Hood video any good.

Probably not, due to the steepness of the terrain.

rw2 said:

Considering that a bunch of people fell off a mountain and a helicopter crashed all I can say is "Holy crap did a lot of stuff go right!"

I guess they didn't have many options especially being there was a person in the basket tethered to the helicopter and no level place to set down.

Here is my understanding of what happened.

There were two helicopters that initially responded to the call. One was an experienced Oregon National Guard Blackhawk crew. The second an Air-force reserve Pave-hawk. The Guard helicopter was a much more experienced crew and hoisted the first 2 patients. I was told that the second helicopter was going to wait for the first one to return from the hospital in Portland and not attempt the hoist. Now this is all here say, because the military does not post their accident investigations like the NTSB.

The second helicopter went in to perform the hoist anyway. He was too heavily loaded at the time with fuel and crew. Had he done a proper performance calculation it would have shone the aircraft was too heavy for the altitude and temps. Its a bit of a trap when you are used to flying a very high performance helicopter a lower elevations. These aircraft are used to having tons of power reserve and you don't worry much performance calculations at lower altitudes.

So into the hover they go. Everything is looking good. The Torque meter (shows how much power is going to the transmission) is not close to the redline. Problem is they are now engine limited and the engines are right at their max power output, which at that altitude is much less horse power than at sea level. Still they are able to hover (for now). Well the winds are a little shifty and here comes a little down draft. The Pilot pulls in a little more collective to maintain his hover hight. The engines need to produce more power to maintain rotor RPM. They are maxed so rotor RPM starts to decay. You can see this in the video as the rotor blade angle begins to cone upward. Now here comes the real problem, the main rotor and tail rotor are mechanically driven together. A 3% drop in main rotor RPM equals a good 10% or more drop in tail rotor RPM. In an american helicopter the tail rotor pushes the nose left to counter act the torque of the engines and main rotor system.The pilot pushes the left pedal to the stop to arrest the right turn. The increase in pitch in the tail rotor blades requires more power(which is not available) and the rotor RPM further decreases. At this point the aircraft begins to settle into its own down wash and the bottom falls out. The pilot pulls back on the cyclic to get away from the mountain and the people on the ground. The crew man in the back severs the cable. The only way out is airspeed. Helicopter pilots are trained to get forward airspeed to recover. Well the mountain is now in front of the nose. You could fly out of it backwards but you can't see and crater rock is some where behind you. Its just not something most helicopter pilots have done before.


For the question on rolling the throttle off. That is a way to get out of settling with power but its not recommended. In the mount hood crash it would stop the right turn. But the increase in decent rate required would just make the impact that much sooner.

One thing I find interesting is there is a place to land a Blackhawk just 500 ft below where the accident happened. The patient could have been lowered down the snow slope to there and placed inside the helicopter while it was on the ground. Helicopters can do amazing things, but the more amazing the greater the risk of an accident.


Here is another good one where a pilot did not take high altitude in to account. This guy probably does these return to target runs all day long at lower elevation. Things take a little longer to pull out of at high elevation.
[youtube]Cqrh8WYnvaA[youtube]

http://www.youtube.com/watch?v=Cqrh8WYnvaA

TCJ, The Hughs 500, we called it a Loach, did a hovering autorotation. If there was room, he could have just moved the cyclic forward to fly to clean air or moved the collective down to regain turns (full rotor rpm.) If he had approached too fast, then extra power was necessary to slow down. The mountain school at Ft. Carson taught us to make very slow approaches to prevent having to pull a lot of power, loosing tailrotor effectiveness, and spinning in. We actually zeroed the airspeed, set torque to that required to hover at three feet, and didn't touch the collective all the way in. To go up on our glide angle, we pushed the collective forward a bit. To go down on our glide angle, we made a circular motion with the collective to settle with power a bit.
Waterboy, What did you fly?

Jim, Apache 21 1/9th, Stogie 21 3/17th

Thanks for the explanations Waterboy and Contact. I have ridden hundreds of hours in helicopters in the mountains and continue to be fascinated by them and the skill of the pilots.

Here's the "Loach"

contactflying wrote: To go down on our glide angle, we made a circular motion with the collective to settle with power a bit.

Jim, Apache 21 1/9th, Stogie 21 3/17th

How do you make a "circular motion with the collective"?

MTV

Maybe if it's wore-out enough or pull really, really hard?

Typo's aside, this is interesting reading. I am fascinated with those things...never be within reach for me but fun to dream.

Hold my beer and watch this moment. And I thought some of my landings are rough. I can't hold a candle to this guy. I wonder what his first words were? If I had 35" Alaskan Bushwheels I could have saved it. I'm sure glad I got the rental insurance. Fly it like you STOL it. Pun intended. Hey look, they have a camera, lets give em a show. What was it John Wayne said? "Life is tough" _______________

Loach was how we pronounced LOH or Light Observation Helicopter. The OH6-A or Hughs 500 replaced the old Bell 47. The OH-58 or Bell Jet Ranger replaced the OH6-A and was such a pig we refused to call it a Loach. The Loach was so maneuverable that an Air Cav Trooper could stand on the skids and sword fight with Charlie. Articulated rotors are not so prone to mast bumping. The 58 was preferred by Colonels who didn't like having a transmission two inches from their ears in the back seat of a Loach. Torques, back seat gunners, took the seat out and set on the floor with their feet on the skid.

transmission two inches from their ears in the back seat of a Loach

I have hearing aids in both ears as a result of sitting next to that wine without ear plugs.

The Loach was so maneuverable...

our Young Viet Nam vet pilot often entertained us with stories of hovering around under the triple tree canopy in the jungle.

Torques, back seat gunners, took the seat out and set on the floor with their feet on the skid.

We took the backseats out and two of us sat on the floor with a chainsaw pack between us and shovels and Pulaskis under our knees.

Waterboy, What did you fly?



Contact,

I currently make a living as a civilian helicopter driver. My latest job in in the Skycrane. I have slowly worked my way up through the industry over the last 18 years. I have specialized in fire fighting and helisking over the last 10. My favorite long line machine is the AH1-F Cobra. Yep long line in a Cobra, unfortunately it will never be allowed again. The Bell 205 or a H model Huey with a cobra(703) motor would be my favorite all around machine. And if you told me I could only pick one it would be the AS350 Astar (yep its french).

Oh by the way, I fly my airplane approaches using the same rate of closure technique I do in the helicopter. The same method you talk about. It puts me on the spot every time.

Waterboy, I flew the AH1-G in Vietnam. It had the TH53-L-13 engine. The Army would never let a Cav pilot fly anything as expensive as a Skycrane. I need you to help me sell the apparent rate of closure approach to our fellow pilots. I think its simplicity makes pilots think it is bogus. Also, it is hard to wean pilots off the airspeed indicator.

contactflying wrote:Waterboy, I flew the AH1-G in Vietnam. It had the TH53-L-13 engine. The Army would never let a Cav pilot fly anything as expensive as a Skycrane. I need you to help me sell the apparent rate of closure approach to our fellow pilots. I think its simplicity makes pilots think it is bogus. Also, it is hard to wean pilots off the airspeed indicator.

A lot of us use the technique, we just never had a name for it.

+++++1 on the ASI and reserve lift indicator addictions.

Gump

Gump, In the old days I never met a crop duster who didn't. Some of these young guys with jet engines get a little happy with the beta and drive the boss crazy about prop damage.