Question about the birth of autorotation

benyflyguy

benyflyguy

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Our field now has a guy giving helicopter lessons. Pretty neat to watch. I was watching them earlier coming in high on final and just drop out of the sky practicing engine out autorotation stuff. Super cool but terrifying as well iMo. Got me thinking about how they ever came up with that?? Theoretical plan they tested? Or something they just were playing around one day??
Watching them practice does make me want to take a lesson or two for fun.
 
benyflyguy said:
Got me thinking about how they ever came up with that??
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As mentioned above the autorotation pre-dates the helicopter with the autogiro developed by a Spanish engineer in the 20s. It flew by means of a continuous autorotation. Given a helicopter and autogiro use the same basic rotor/control system it was an original feature of the helicopter.
 
Bell206 said:
As mentioned above the autorotation pre-dates the helicopter with the autogiro developed by a Spanish engineer in the 20s. It flew by means of a continuous autorotation. Given a helicopter and autogiro use the same basic rotor/control system it was an original feature of the helicopter.
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Maple seeds have been autorotating for a long time. Maybe where the Spanish engineer got the idea.
 
Piperonca said:
Maple seeds have been autorotating for a long time. Maybe where the Spanish engineer got the idea.
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They had been "autorotating" aircraft since before the Spanish guy... he just developed a useable application of it that made it into the helicopter side. No clue where the original idea came from but it was probably from old China as that is where the 1st examples of a rotorcraft come from that even pre-date DaVinci's "air screw."
 
I thought it was just some guy deciding he had to figure out something to do after the engine quit on his copter!

I kid, I kid! :D
 
Bell206 said:
They had been "autorotating" aircraft since before the Spanish guy... he just developed a useable application of it that made it into the helicopter side. No clue where the original idea came from but it was probably from old China as that is where the 1st examples of a rotorcraft come from that even pre-date DaVinci's "air screw."
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I still think the "air screw" sounds appealing.
 
Maybe one of you military helicopter pilots will chime in............but at one time I heard that the Army was not teaching auto-rotations because they were losing my helicopters in training than in actual engine outs in the field
 
They stopped full autos to the ground. Instead they train autos from altitude but with a power recovery at the bottom prior to touchdown. Same as the civilian side except some operators still train full down autos to land and water.
 
Racerx said:
I still think the "air screw" sounds appealing.
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Reminds me of an old joke about Army helicopter pilots vs. Navy/Air Force jet pilots. The difference is the jets blow their way through the air and the helicopters...
 
Bell206 said:
They stopped full autos to the ground. Instead they train autos from altitude but with a power recovery at the bottom prior to touchdown. Same as the civilian side except some operators still train full down autos to land and water.
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Now they are doing initial training in the Lakota (EC145) so no need for even the basic auto... Long way from a TH-55...
 
Twin engines did away with Full autorotations to the ground for the Army and frankly can’t think of a twin engine aircraft that Autos well other than a Chinook…and if you seen one do one it’s really cool…
 
kgruber said:
Maybe one of you military helicopter pilots will chime in............but at one time I heard that the Army was not teaching auto-rotations because they were losing my helicopters in training than in actual engine outs in the field
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Don’t know of a time when they actually stopped doing autos. Autos to the ground are prohibited for multi-engine helicopters in the Army. Since 99 % of their fleet is multi-engine these days, unless you’re flying SE and an IP/SP in 160th, Flight Concepts, or an XP (test pilot) at USNTPS, you won’t be doing autos to the ground.
 
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k9medic said:
Long way from a TH-55
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TH-55? That was retired ages ago. The last time I was at Cairns they were using TH-67s for initial and performing autos. When did they switch to the 72s for initial? Must have been recent.
 
Bell206 said:
TH-55? That was retired ages ago. The last time I was at Cairns they were using TH-67s for initial and performing autos. When did they switch to the 72s for initial? Must have been recent.
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It was...just a few years ago. Had a friend go through.
 
@Bell206 the TH55 reference was just being silly. The children of the magenta line will never know what it is like to have to actually twist a throttle to maintain RPM.

The 67's were retired about 8 years ago for the most part and I believe that they were all transferred to DRMO/DLA. I know I picked up one of the last 58's a couple of years back and there were 2 67's sitting waiting for their new municipal government owners.

We do autos in the simulator for twins that I fly. An organization where I fly the 58 and the 407 part time still slams them to the ground.
 
The mighty Creek served from 1993-2021.
 
I remember standing around watching OH-58s doing autos one day awaiting my turn (student switch). A 58 came in doing a low level auto and flared way too late. Tail hit hard and slid down the lane. I was like, “is it me or does the tail look bent upward?” We all couldn’t tell from 100 yards away so we dismissed it as an optical illusion and the aircraft continued training. Anyway, the next day, they showed a pic of a bent tail boom and sure enough, was the same tail code we saw. Off course the crew just hopped on the bus and didn’t report it on post flight. Come to find out, it was the CO (Captain) doing a currency ride. Two staffers that spend their days sitting behind a desk…an accident waiting to happen. ;)
 
Velocity173 said:
I was like, “is it me or does the tail look bent upward?”
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Knew a training pilot finishing up a recurrent ride in a 206L when after a "normal" full down auto the right seater stated the pedals were locked. After a few checks the training guy opened his door and looked back to see the tailboom touching the ground. That poor training ship probably had a dozen tailbooms put on it over the years. What was ironic we had a 206B on fixed floats for water autos and the most it had were a few flat tires on occasion.
k9medic said:
The 67's were retired about 8 years ago
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k9medic said:
Should have said, "started to be retired" for the Creek.
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That makes more sense since I saw them flying at Rucker a couple years ago.;)
 
Velocity173 said:
I remember standing around watching OH-58s doing autos one day awaiting my turn (student switch). A 58 came in doing a low level auto and flared way too late. Tail hit hard and slid down the lane. I was like, “is it me or does the tail look bent upward?” We all couldn’t tell from 100 yards away so we dismissed it as an optical illusion and the aircraft continued training. Anyway, the next day, they showed a pic of a bent tail boom and sure enough, was the same tail code we saw. Off course the crew just hopped on the bus and didn’t report it on post flight. Come to find out, it was the CO (Captain) doing a currency ride. Two staffers that spend their days sitting behind a desk…an accident waiting to happen. ;)
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Low rotor rpm and a bad Auto induced a condition called pylon whirl that would swing the whole tail boom around in circles like a fixed hula hoop when in contact with the ground…it could break off the tail or bend it as you observed…bent it’s actually hard to detect in the cockpit and was normally reported by an observer…or on inspection.
 
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Warlock said:
Low rotor rpm and a bad Auto induced a condition called pylon whirl that would swing the whole tail boom around in circles like a fixed hula hoop when in contact with the ground…it could break off the tail or bend it as you observed…bent it’s actually hard to detect in the cockpit and was normally reported by an observer…or on inspection.
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Spike Knock too. Friend of mine (student) doing an auto in a 67 hit so hard they bent the skids and got Spike Knock from the impact. They were actually above the DA limit (3,000 ft)to be doing autos.
 
The operator that I flew for did autos over water in a float BH 206B. Take off from a fifty foot tower and expect a throttle cut at ten knots AS. The Navy training fields near my house, (Spencer and Wallace Fields) do only straight ins with a power recovery. When I was in flight school, my class did 180 autos to the ground in OH-23Ds, solo. Once, when I was in the IFR phase, (UH-1A inst trainer) my IP told me to take off the hood. We went to a stage field with no traffic. He showed me a low level auto. Not an authorized maneuver. 105 kts, 15 feet altitude, chop the throttle. He had me do a couple and they were total fun. I was logging hood in that period. My IP knew that I had begun the course with a FAA Com ASEL with Inst in my pocket so he was not robbing me of any instrument training.
 
Back in the stone age, when I went through the CH-47B AQC, we would spend 90% of our training session on full autos to a running landing. We would hurriedly knock out the slopes and a sling load and use up the rest of our fuel doing autos.

The Instructor would open the manual (emergency) trim switches and beep both the engines down to idle, so there was very little time to get the engines back on line if a go-around was necessary. There were no go-arounds in training...

When I got to my unit in Korea, we had Super C-Models and eventually the new and improved fiberglass composite rotor blades. The difference in the glide ratio with the big blades made doing autos a very different training event. Because the empty Chinook would float like crazy, we would have to enter autorotation way farther out from the runway. We still do simulated dual engine failures in the simulator and they are very survivable.
 
I heard in the Huey you could do a hovering auto, touch down, come back up and touchdown again with RPM to spare.
 
Maxnr said:
65-10
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My class was 67-4. We heard about the solo autos but didn't get to do them because of the Army's desire to cut the high accident rate. Of course, after flight school stuck at Ft. Eustis waiting on orders, I did solo autos in an OH-13 about every time I flew it. Us staff people would have to fly weekends, typically Sunday for proficiency. Had Felker Field to myself quite often.
 
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Velocity173 said:
I heard in the Huey you could do a hovering auto, touch down, come back up and touchdown again with RPM to spare.
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No doubt you could do that. It had plenty of inertia. My favorite thing was to very gently lower the left skid heel to the ground so that you couldn't feel it, then slowly let the aircraft settle on the skids, cushioning very gradually with collective so the net result was a hovering autorotation with no impact feel at all.

When OH-58s came out in the early '70s I got one of the first transitions at Hood. IP did a straight in zero ground run auto, then picked it up and did a complete pedal turn to the runway heading before rotor finally bled off. He was good. I never tried it.
 
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Solo autos…unbelievable. Army is so risk averse today, “solo” is two students flying only VMC approaches in perfect weather conditions.

I got handpicked to solo twice though when another student’s stick buddy tapped out. First approach, dude rolls the throttle down at hover! Low rotor alarm goes off and we slam onto the pavement. I look over at him and he’s like “sometimes I get nervous and roll the throttle off.” :eek: Now that I think about it, probably a good thing the Army doesn’t do a true solo anymore.
 
When I was a commercial pilot, I was co-piloting with a guy named John. We were re-poing back home at the end of the day. Ops called and said that the corporate board of directors were in house. Look sharp. I was on the controls, in a six foot hover taxi to parking. John, the impish scallowag that he was, said "Bet you can't hover taxi in this cross wind with the autopilots off." I said "Oh yeah?" He then punched them off. Over parking, he then chopped both throttles and I suddenly had an unplanned hovering auto. It came off OK despite it being my first hovering auto in the "Igor" 76. Had to pull it off with that audience.
 
Love good helicopter stories. In RVN one of our senior aircraft commanders had a UH-1H hydraulic failure out in the Area of Operations. He flew it back to the unit, hovered over to the maintenance pad next to the hangar and casually set it down. No fuss at all. Didn't go to the Marine fixed wing base next door, call fire trucks, or any of that. What got me was his skill. Not a big guy, only about 150 lbs soaking wet so it wasn't brute strength. If you've ever done hydraulics off in a Huey you know what I'm talking about.
 
Yes you could autorotate a UH-1 and an AH-1 ( Army single engine) lightly loaded and pick back up to a low hover and do a 180 degree pedal turn…but you had to be good…hydraulics off was always am I going to die if it goes hard over…and impossible in a snake from the front seat but not to bad in the back. As you say technique was everything…
 
Piperonca said:
Love good helicopter stories. In RVN one of our senior aircraft commanders had a UH-1H hydraulic failure out in the Area of Operations. He flew it back to the unit, hovered over to the maintenance pad next to the hangar and casually set it down. No fuss at all. Didn't go to the Marine fixed wing base next door, call fire trucks, or any of that. What got me was his skill. Not a big guy, only about 150 lbs soaking wet so it wasn't brute strength. If you've ever done hydraulics off in a Huey you know what I'm talking about.
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I did most of my instrument phase with the hydraulics off and stick friction on. I never did like the overboosted feel of those ancient hydraulics...
 
IK04 said:
I did most of my instrument phase with the hydraulics off and stick friction on. I never did like the overboosted feel of those ancient hydraulics...
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You a bad MF, GI
 
Ain’t nothing until you do autos with hydraulics off…with a sling load.
 
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