zero airspeed fulldown autorotation

Hello,

I would like to discuss some interesting info and thoughts.

I know that there are helicopters that can do an auto to the ground
perfectly soft with no airspeed and no flare.
I know somebody who did it in an R44.
Then I heard somebody telling about one in a R22 with two persons,
piloted - of course - by TT. I couldn't believe and neither could any
colleague.

But I did some quick calculations and if there is no big mistake, it is
theoretically easily possible. Of course there is the timing issue ;-) I
don't want to try it.

I took the 100HPsec (rotor energy at 104%) out of the R22 flight
training guide and converted them to 74 kJ.

The kinetic energy in a 1200lbs R22 descending at 1500ft/min translates
to only 16kJ. Even at 1370lbs and 2000 ft/min it is still less than half
(namely 31 kJ) of the energy in the rotor at 104%!!!

Of course you cannot get out 100% of the rotor energy, only down to
about 80% at sea level and aerodynamic efficiency is bad. But hey, you
can go up to 110% and at 1200lbs it is only 16 kJ, less than a quarter
of the rotor energy.

I do not want to have anyone try it, but has anyone here ever done such
a thing in any helicopter?

I'm NOT talking about the dead man's curve!!!
I'm talking about a perfectly established auto with zero airspeed at
high rotor rpm which needs several hundred feet for establishing!
There is no way to assume one could do it after an engine failure in
300ft AGL at 20kts!!!

In message
Stefan L. wrote:

Hello,

I would like to discuss some interesting info and thoughts.

I know that there are helicopters that can do an auto to the ground
perfectly soft with no airspeed and no flare.
I know somebody who did it in an R44.
Then I heard somebody telling about one in a R22 with two persons,
piloted - of course - by TT. I couldn't believe and neither could any
colleague.

But I did some quick calculations and if there is no big mistake, it is
theoretically easily possible. Of course there is the timing issue ;-) I
don't want to try it.

I took the 100HPsec (rotor energy at 104%) out of the R22 flight
training guide and converted them to 74 kJ.

The kinetic energy in a 1200lbs R22 descending at 1500ft/min translates
to only 16kJ. Even at 1370lbs and 2000 ft/min it is still less than half
(namely 31 kJ) of the energy in the rotor at 104%!!!

Of course you cannot get out 100% of the rotor energy, only down to
about 80% at sea level and aerodynamic efficiency is bad. But hey, you
can go up to 110% and at 1200lbs it is only 16 kJ, less than a quarter
of the rotor energy.

I do not want to have anyone try it, but has anyone here ever done such
a thing in any helicopter?

I'm NOT talking about the dead man's curve!!!
I'm talking about a perfectly established auto with zero airspeed at
high rotor rpm which needs several hundred feet for establishing!
There is no way to assume one could do it after an engine failure in
300ft AGL at 20kts!!!
Yes I have done zero speed full touchdown autos in both R22 and R44.
However I should point out that these were with an FIE (Flight
Instructor Examiner) in the UK, who has in excess of 35,000 helicopter
hours. My own experience is such that I would not dream of doing them
on my own, except if I had a real emergency to deal with. In the R22
we were within 50lbs of 1370lbs, and the timing at the bottom is
absolutely spit second.

Ian Whitmore

On Aug 29, 4:08 pm, wrote:
In message
Stefan L. wrote:



Hello,
I would like to discuss some interesting info and thoughts.
I know that there are helicopters that can do an auto to the ground
perfectly soft with no airspeed and no flare.
I know somebody who did it in an R44.
Then I heard somebody telling about one in a R22 with two persons,
piloted - of course - by TT. I couldn't believe and neither could any
colleague.
But I did some quick calculations and if there is no big mistake, it is
theoretically easily possible. Of course there is the timing issue ;-) I
don't want to try it.
I took the 100HPsec (rotor energy at 104%) out of the R22 flight
training guide and converted them to 74 kJ.
The kinetic energy in a 1200lbs R22 descending at 1500ft/min translates
to only 16kJ. Even at 1370lbs and 2000 ft/min it is still less than half
(namely 31 kJ) of the energy in the rotor at 104%!!!
Of course you cannot get out 100% of the rotor energy, only down to
about 80% at sea level and aerodynamic efficiency is bad. But hey, you
can go up to 110% and at 1200lbs it is only 16 kJ, less than a quarter
of the rotor energy.
I do not want to have anyone try it, but has anyone here ever done such
a thing in any helicopter?
I'm NOT talking about the dead man's curve!!!
I'm talking about a perfectly established auto with zero airspeed at
high rotor rpm which needs several hundred feet for establishing!
There is no way to assume one could do it after an engine failure in
300ft AGL at 20kts!!!

Yes I have done zero speed full touchdown autos in both R22 and R44.
However I should point out that these were with an FIE (Flight
Instructor Examiner) in the UK, who has in excess of 35,000 helicopter
hours. My own experience is such that I would not dream of doing them
on my own, except if I had a real emergency to deal with. In the R22
we were within 50lbs of 1370lbs, and the timing at the bottom is
absolutely spit second.

Ian Whitmore

Never flown a 22 or a 44 but I've done it in a 300C with 2 people and
a half load of fuel from 400 agl. timing is everything. Zero airspeed
touchdown, no flare. It is easy to do auto's to the ground if you get
a lot of practice. I was trained by Lester Hembel, he was an awesome
pilot and instructor. He trained over 15,000 people and agreed to
teach me full touchdowns in a B model. Most fun I ever had learning.
We did many hours of it.

3000 pic 269b, 300c, Hughes and Schweizer, 206BIII. 5 engine failures,
all no damage, full touchdown autos. 1 was loss of throttle cable on a
B model.... slow decay in RPM, missed some small trees and landed in a
gully... too much fun... lol. rest of autos were in Florida, 1 I
landed on a big dirt pile in downtown Ft. Myers construction site,
only other option was the river, I didn't feel like a swim that
morning. Stuck valve. managed to restart and fly out. Rest were in
open places in the stix.

Missed one crash by 1 hour as I refused to fly it. Somebody else got
that honor. No I don't work for them anymore... lol they killed a
friend of mine from their lack of maintenance, upside down on a golf
course at 80 knots in an Astar. Lost the swash plate... not too good.
He did manage to turn off the fuel beforehand though.

It is a strange sound "flying" with no engine noise in a
helicopter.... or any powered aircraft for that manner.

Larry Howle