Backwards auto-rotation?
Joined: Sep 2001
Posts: 600
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From: In the Haven of Peace
LB - Now it's Crystal Clear!
Lightning Boy,
When I first started reading your post I thought you were serious, then I thought...what a Richard Cranium, then I larfed out loud. Brilliant . When I go down the hood and chill out with ma homies over a few cold Felin Foels, I'll be able to explain it all to them perfectly.
When I first started reading your post I thought you were serious, then I thought...what a Richard Cranium, then I larfed out loud. Brilliant
. When I go down the hood and chill out with ma homies over a few cold Felin Foels, I'll be able to explain it all to them perfectly.
Joined: Feb 2005
Posts: 1,957
Likes: 0
From: Australia
BaT-Off
I think you well qualified the answers you got with your own response.
Too bad, and here I was thinking all along that you are asking about backwards autos, (to the ground) when all along all you wanted to know about was auto-rotational flight, going backwards sideways or any which way. Big bloody deal! Fair dinkum, have ye not got a reverse gear in your motor scooter to play with?
There was an urban myth around about thirty years ago, that one, who used to go by the nick-name Barnacle Bill, used to do-em in a 3B1 up in the oz outback.
He now is i believe a mine host of a hosteliery in Ireland someplace. Now that would be a good spot to drop in for a lemonade as you folks do over there.
Any one knows him drop in and shout him one for me, I owe him one from way back. yeah 1975 I think it was.
tet
I think you well qualified the answers you got with your own response.
Too bad, and here I was thinking all along that you are asking about backwards autos, (to the ground) when all along all you wanted to know about was auto-rotational flight, going backwards sideways or any which way. Big bloody deal! Fair dinkum, have ye not got a reverse gear in your motor scooter to play with?
There was an urban myth around about thirty years ago, that one, who used to go by the nick-name Barnacle Bill, used to do-em in a 3B1 up in the oz outback.
He now is i believe a mine host of a hosteliery in Ireland someplace. Now that would be a good spot to drop in for a lemonade as you folks do over there.
Any one knows him drop in and shout him one for me, I owe him one from way back. yeah 1975 I think it was.
tet
Joined: Nov 2003
Posts: 185
Likes: 0
Bat-Off,
Yep, they are a tough crowd to please, clearly. Whatever you have been taught to conceptualise what is going on doesn't really matter so long as it works. If you want to think of pockets of air, then fine. Not my choice of analogy, but there we go.
It is possible to move backwards during an autorotation. I did this in my commercial checkride, when the examiner cut the throttle right over a good spot, with a brisk headwind.
I was 1500-2000, so simply entered the auto and flared. My flare assisted in the RPM recovery, until I had a sufficient rate of decent to keep the autorotative flow through the disc. (Maybe this is the 'pocket of air' you describe. I prefer simply to think of the autorotative flow up through the disc as keeping you in auto. To get that you need to be falling.)
Then using a little aft cyclic, I was able to drift backwards (the headwind helping) until the spot came back into the window.
During this (any) backwards flight, it is important to remember that excessive speeds will cause instability due to weather-vaning, and could possibly put execessive loads on the structures (tail boom) which the aircraft is not designed for. So this is not an aggressive backwards flight.
Also, it wasn't completly backwards. It was 'sideways/backwards' so that I could keep my intended spot in view.
It is absolutely important to keep an eye on altitude, since airspeed recovery takes a couple of hundred feet longer (depending on the aircraft). My limit was 600'. I must be recovering airspeed by 600'.
Also the sight picture of the spot is slightly different, since you must account for this extra 200' drop to get the required airspeed.
After that, everything is just the same as a normal autorotation.
------------------------------------------
This is not the zero-airspeed / constant attitude autorotations which the others are talking about. It's just an extra method to get you out of trouble. If you have not been demonstrated one, ask someone to show you. It's another string to your bow which could save your life.
cl12pv2s
Yep, they are a tough crowd to please, clearly. Whatever you have been taught to conceptualise what is going on doesn't really matter so long as it works. If you want to think of pockets of air, then fine. Not my choice of analogy, but there we go.
It is possible to move backwards during an autorotation. I did this in my commercial checkride, when the examiner cut the throttle right over a good spot, with a brisk headwind.
I was 1500-2000, so simply entered the auto and flared. My flare assisted in the RPM recovery, until I had a sufficient rate of decent to keep the autorotative flow through the disc. (Maybe this is the 'pocket of air' you describe. I prefer simply to think of the autorotative flow up through the disc as keeping you in auto. To get that you need to be falling.)
Then using a little aft cyclic, I was able to drift backwards (the headwind helping) until the spot came back into the window.
During this (any) backwards flight, it is important to remember that excessive speeds will cause instability due to weather-vaning, and could possibly put execessive loads on the structures (tail boom) which the aircraft is not designed for. So this is not an aggressive backwards flight.
Also, it wasn't completly backwards. It was 'sideways/backwards' so that I could keep my intended spot in view.
It is absolutely important to keep an eye on altitude, since airspeed recovery takes a couple of hundred feet longer (depending on the aircraft). My limit was 600'. I must be recovering airspeed by 600'.
Also the sight picture of the spot is slightly different, since you must account for this extra 200' drop to get the required airspeed.
After that, everything is just the same as a normal autorotation.
------------------------------------------
This is not the zero-airspeed / constant attitude autorotations which the others are talking about. It's just an extra method to get you out of trouble. If you have not been demonstrated one, ask someone to show you. It's another string to your bow which could save your life.
cl12pv2s
Joined: Jul 2000
Posts: 794
Likes: 8
From: Wiltshire
Irrespective of the type of auto flown initially, it is not difficult to achieve a zero groundspeed touchdown at the end of the flare - just takes a bit of judgement and a 10kt headwind helps.
Do remember being shown a constant attitude auto in a 500 at the McDonald Douglas factory. High altitude, high OAT, no wind and a heavy aircraft. The test pilot flew a 40kt auto, then raised the nose about 10 degrees or so, he just gradually raised the lever during the last 20ft to achieve a perfect 0/0 touchdown. Very impressive, but a VERY experienced pilot who had flown thousands of EOLs.
Do remember being shown a constant attitude auto in a 500 at the McDonald Douglas factory. High altitude, high OAT, no wind and a heavy aircraft. The test pilot flew a 40kt auto, then raised the nose about 10 degrees or so, he just gradually raised the lever during the last 20ft to achieve a perfect 0/0 touchdown. Very impressive, but a VERY experienced pilot who had flown thousands of EOLs.
Joined: Dec 2001
Posts: 943
Likes: 0
From: Gold Coast, Queensland
I spent quite a few years flying in PNG & Tasmania. The countryside was mainly tall trees with limited holes for EOL. I decided a slightly heavy landing in a hole was better than a pretty landing in a 100 ft tree, so I practiced constant speed EOL with zero ground speed. In auto any helicopter can go forwards, sideways, backwards & do spot turns if you want. I took all our pilots up & taught them how to make a zero speed landing from any height. If you find a spot to land but undershoot into a tree, you are stuffed. So quite simply I got them to overshoot & at any height when over the spot, flare to zero & drop vertically onto the spot. They were all surprised how easy it was with practice. I did this in the Enstrom, 206, AS 350, H500, BO105 & a few in a S76 but to recovery. After several thousand of these, no helicopter was damaged or stressed. Yes it takes practice, but it sure beats hitting a tree.
Joined: Oct 2007
Posts: 230
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From: An Irish dude in Houston, TX. I miss home!!!
Check out www.iwantallinformationspoonfedtome.org or pay an instructor for some ground lessons.
Joined: Feb 2011
Posts: 9
Likes: 0
From: Australia
backwards forwards
I remember doing Autos with Buck Ryan in a G2, as well as turning off the mags occasionaly he would get you to go backwards sometimes to position better for the end game. I have been up with a good pilot at Mt Isa in an R22 who would demonstrate pedal turns in auto, his aim was to make you comfortable with autos and understand that everything still works the same. The same guy did my mustering endorsement and he would make you fly around for 30 mins just above translation with your feet off the pedals (pre govenor) and basically use the throttle to maintain directional control.
Joined: Feb 2005
Posts: 1,957
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From: Australia
'Old Buck'
last spoke to him on the night of his send off, and Bryce, an emotional time. always cussed myself for not getting to see him more often before he headed off.
taught me about being careful not to drain too much fuel out of the carby on the gravity feed system in the G2, "in case you didn't have enough innit to startit".
yeah, took about three weeks to wake up, and those traffic lights at the parafield aero club, gees . then he'd order us into the pubs in Rundle street first to clean the poofters out so's he could have a decent drink in pleasant company,. he was the one who coined the phrase, daytime for helicopter flying, nightime for drinking, our hero.
last spoke to him on the night of his send off, and Bryce, an emotional time. always cussed myself for not getting to see him more often before he headed off.
taught me about being careful not to drain too much fuel out of the carby on the gravity feed system in the G2, "in case you didn't have enough innit to startit".
yeah, took about three weeks to wake up, and those traffic lights at the parafield aero club, gees . then he'd order us into the pubs in Rundle street first to clean the poofters out so's he could have a decent drink in pleasant company,. he was the one who coined the phrase, daytime for helicopter flying, nightime for drinking, our hero.
Joined: Jan 2005
Posts: 1,529
Likes: 2
From: yorkshire uk
used to do backward autos with Robin Simpson at Hooks . Every time i tried to do a 270 -360 auto into a small opening in the trees i would lose it or come on heading too low etc the backward auto means you keep the site in view or at least know where it is . Of course you need to be pushing nose down around 300 ft at v latest . Then no different to hovver auto from say 200 -250 ft ( this was in 206 so may be more in different machine ) . It does however need practice !!
Joined: Feb 2011
Posts: 9
Likes: 0
From: Australia
Personaly I dont like losing any airspeed in Auto, if you are high and over the target I am a big advocate for keeping your airspeed up and always keeping your target in sight, just fly arcs and always be able to turn and make for target at any time in your arc.
