note sure how to embed this one.
Seahawk you'll cringe when you see this one.
pucker factor through the roof

https://dailybuzz.nl/media/2022/10/6/7e3905f0-455b-11ed-92c2-10ddb1b30d21/heli-net-aan_web_wm.mp4

He’ll be cleaning his shorts for a week after that!

A month! Sweet Baby James.

Mountain flying, and I went to the school in Fallon decades ago, is arguably harder that landing on small ships in big seas. I could go into all the reasons, but the video is extraordinary.

In my mind, and I have done accident investigation where video complicates the investigation, the pilot lost tail rotor authority, meaning the tail rotor was not able to overcome main rotor torque. Then the Fairy Dust got sprinkled and they somehow survive to fly again.

I am guessing, which I hate to do, had everything to do with wind direction and velocity. This was not a mechanical failure or straight and level flight, the miracle in the video, could not be achieved.

Can you send me a link? I am cleaning myself up:)

My guess

Thin air
In air both rotor and tail are equally chopping thin air
All torque counterbalanced

The mains goes over rock
Ground effect on rotor gives it extra torque on the mains.
While tail still spins in thin air thus lack of counter torque?

Seahawk, in your opinion, how much of the recovery was the pilot's skill in doing everything right when there's no time to think, vs. just luck?

I kinda like my wings bolted firmly to the fuselage, and using runways.

Rotor systems only see density of air, or DA.

DA affects engine, main rotor and tail rotor performance.

Now, in mission planning, power required calculations are made based on DA, gross vehicle weight, winds, etc.

I don’t see any ground effect due to winds, etc. GE actually helps the the entire power train.

Again, they lost tail rotor authority for any number of reasons, got really lucky, fell below the wind line (blocked by the terrain), regained tail rotor authority and we’re able to fly away.

That is my guess.

Amazing video.

All of the above - that guy is one lucky SOB.

I've got several thousand hours flying in the mountains (not simply "flying", takeoffs and landings), mostly in Alaska and Arizona. He was also coming way too fast.

Made me smile, the wings bolted comment.

I think both. The steep drop off allowed the main rotor to keep spinning...that is fortunate.

The rest, the recovery, the return to flight and the pedal turn is skill IMHO.

I was hoping I didn’t goon it!

It not a 356. . . but the plane is still pretty cool.

http://forums.pelicanparts.com/uploa...1665107699.jpg

But does that density not change , the second the disk transitions from open mountain air, eg 300 feet of nothing below
to just hovering over the mountain top, 10 feet to hard rock?

eg ground effect gives the disk something to"push" off?
causing increase in torque

I mean, the Disk is in fact a big old fan, that moves air down
If the air below the disk can't get away, it will compress

Obviously we aren't talking compressors here, the air can get away..
But Ground effect , is a thing, right?

Hence an overloaded Huey in Nam had to fly circles in an opening
To first gain transitional lift and not just go straight up.


Now if you cross the cliff.. you go from NO ground effect
to Ground effect, in a flash

The tail rotor however, hangs free , no ground effect there.
and due to altitude density.. NO capacity to increase its output. The engine is at mechanical limits.


To me it looks like that is exactly what happened in this video

And as soon as he went back over the clif, both disk and tail rotor in thin air again
control was regained.

Ugh...where on earth do you find all this stuff? Get some seat time in the the real thing. If you're going to educate yourself, get off the internet and do some reading by Ray Prouty.

The vietnam problem with overload, and circling to get to transitional lift is well documented in several books. It is not BS.
If there is not enough power to lift straight up, they circled around in the jungle till there was enough transitional lift. chickenhawk lowlevel hell, i'm not making that up

the rest is me asking a question to Seakhawk

if you can't be bothered to contribute and tell me something, then why bother responding at all?

my bad, transLAtional lift. but ok, feel free to beat me up over that mistake

http://forums.pelicanparts.com/uploa...1665149448.jpg

http://forums.pelicanparts.com/uploa...1665149745.jpg


http://forums.pelicanparts.com/uploa...1665149745.jpg

A few of the things you mentioned are somewhat correct and I'm familiar with Huey ops in Vietnam (I think I read that book as well). You're confusing terms...

The pilot in the video is approaching the ridgeline at what appears to be almost a 90 degree angle (no escape path) and way too fast. His descent rate looks high also which means he's pulling in an armful of collective at the bottom. That sets him up for more problems. Yes, a helicopter will use less power while in ground effect but pinnacles offer virtually no ground effect. Completely different than hovering over a concrete tarmac or runway. He got himself into that mess all on his own. He did have some skill pulling it out at the bottom and flying away from the ridge, however.

The rest we're just playing armchair quarterback - we have no idea what his weight is, the wind is (is there any at all?) or the DA. He may have also experienced loss of tail rotor effectiveness (again, we don't know what the winds were). Some Bell products are more more prone to this than other makes.

ok so armfull of collective, does that no mean he will need way more tail rudder?
So if he's already Full nut on the collective
I would expect him also needing matching anti torque , right?

My "theory", was simply that , that arm full of collective you state
And him already being in thin air where his tail rotor is much less effective
got worse as he goes into ground effect

Or just transitions from forward to zero knots, will require more torque and matching anti torque (forget ground effect)
if the pedal is alread near the stops.. he's going to run into trouble either way no?

perhaps might be pushed beyond its capacity to deliver that antitorque

I mean, it doesn't take much deficient anti torque capacity to make the thing start to spin does it? if he's already at limits..

I suppose wind cresting the mountain top is another option and likely
issue didn't think of that yet

comes in from the left, into the wind, at the very end of the approach, I guess would suck
http://forums.pelicanparts.com/uploa...1665153230.jpg

I'mmm baack:)

The key is you cannot separate main rotor performance and tail rotor performance in terms of power available and power required. They are as one. I would get finger cramps trying to explain "power settling", "settling with power" and any of five other dynamic flight states that keep helicopter pilots awake at night.

Mission planning in helicopters is, especially in mountainous terrain or "high, hot and heavy" operations extremely detailed.

Density altitude is key: Go here: https://www.omnicalculator.com/physics/density-altitude

There were summer days in flight school in Florida where the DA was over 2000ft: Meaning, I could be landing at sea level and the helicopter was operating as if it was at 2000ft of DA. For some helicopters, that is significant.

I flew missions where I calculated my weight at launch, the DA and then expected DA at the drop site...taking into account fuel burn, time of day, etc. We would also plot expected engine performance just prior to launch, there are manuals on how to do that. Those numbers would then get plunked into my numbers.

KNS and I always hesitate to make a sweeping assessment on another pilots misfortune until the facts are known.

I was at MAWTS in Yuma flying with and against the Marines....I was doing the test on the then brand new HH-60H. Morning hop went really well and we decided to do one v one in the afternoon...against both fixed wing and Marine helicopters.

I gooned the math on mission planning. No excuses. My fault.

I was flying a particularly aggressive counter move, very nose down, close to the ground, when I began to lose Nr, or main rotor speed. I "drooped" to around 95% Nr (not good) but I still keep tail rotor authority. The procedure in the 60 is to bring the nose to the horizon, hold or decrease collective (let the power train catch back up) and
re-access.

We were able to fly away. I called "knock off and climbed to 1000ft agl, gave control to the co-pilot and ran my mission planning numbers again.

I found the error. We had plenty of gas the helo was in fine shape so after a few minutes, we continued the hop.

Lesson learned.

and when ask by his sweet Lady..
how was your day..
fine..
the usual..


Rika