Some military aircraft pictures from my travels...

On the PAD: Huey Command Pilot asks if anyone has never ridden in a helicopter before. Second LT says "never" (before we could shut him up). Buckle up. The most amazing low level lift off and down the road through the jungle you have ever experienced.

Didn't know the Huey could autorotate but I guess all can unless severely damaged. Used to watch the PEDRO's HH-43 do autorotate as practice. Then saw them do the real thing with full motor to blow the fire out as crash rescue saved the pilot.

They all autorotate.
 
They all autorotate.

Right down to impact! :eek:

Seriously...that looks scary and I have bad history... I have been a first responder (twice) at an autorotation that went wrong. Thankfully each time I pulled out survivors; no fatalities!

Looks like a maneuver of great practice, skill, and seriously good timing!

Steve
USAFA ALO
USAFA '83
 
Well, I tried my first practice auto today, and made a rookie mistake. Good thing the IP has been doing this for 40 years, and knew exactly what was about to happen!


(I pulled too much collective at 15ft, then almost pushed it back down. :eek: :redface: My brain was about a half-second late in realizing how bad an idea that would have been.)
 
Well, I tried my first practice auto today, and made a rookie mistake. Good thing the IP has been doing this for 40 years, and knew exactly what was about to happen!


(I pulled too much collective at 15ft, then almost pushed it back down. :eek: :redface: My brain was about a half-second late in realizing how bad an idea that would have been.)

Uh, yeah. If you pop initial too early, just hooooollllld what ya got. What were you flying? Is this military or civilian?
 
Yeah, I pulled initial at the right time, just too much.
UH-1H out of Rucker
 
Yeah, I pulled initial at the right time, just too much.
UH-1H out of Rucker

Same, same. You're fine in a Huey. That high inertia rotor is very forgiving. A low-inertia system like most of our advanced birds have, and you'd be buying an aircraft. The Huey is likely the last aircraft you'll take to the ground.
 
Same, same. You're fine in a Huey. That high inertia rotor is very forgiving. A low-inertia system like most of our advanced birds have, and you'd be buying an aircraft. The Huey is likely the last aircraft you'll take to the ground.

So educate this jet pilot that has about 1.5 hours of HYSTERICAL antics at the controls of a Huey (thanks to a classmate who I took up in the backseat later for payback)

Would the "low-interia" types you speak of include the UH-60 and the MD500E? I ask because I watched both of them practicing auto rotations and both crashed, and they looked VERY similar. Those were the two I responded to. Both looked the same: seemed like all the others but then in each the nose pitched really high and the tail dropped really low and then "splat!"

I was just really pleased to get the crews out and to be pleasantly surprised that they were, basically, okay.

Steve
USAFA ALO
USAFA '83
 
So educate this jet pilot that has about 1.5 hours of HYSTERICAL antics at the controls of a Huey (thanks to a classmate who I took up in the backseat later for payback)

Would the "low-interia" types you speak of include the UH-60 and the MD500E? I ask because I watched both of them practicing auto rotations and both crashed, and they looked VERY similar. Those were the two I responded to. Both looked the same: seemed like all the others but then in each the nose pitched really high and the tail dropped really low and then "splat!"

I was just really pleased to get the crews out and to be pleasantly surprised that they were, basically, okay.

Steve
USAFA ALO
USAFA '83

I hesitate to speculate on the cause of any failed autorotation, as there are so many factors involved. Airspeed, attitude, rotor rpm, initial pitch pull, DA, and gross weight all play a huge role.

But yes, both aircraft have low-inertia rotors. They are very common now, and they shed RPM very, very quickly. They also overspeed quite easily. Neither is good for business.
 
They also overspeed quite easily...

Overspeed? Sorry I had to ask the stupid question but what is this? I don't know much of anything about rotary type aircraft so this thread is a great learning about how some of it works.
 
Overspeed? Sorry I had to ask the stupid question but what is this? I don't know much of anything about rotary type aircraft so this thread is a great learning about how some of it works.

Rotors have an operating RPM range. Below that range, the rotor is "underspeeding" and provides ineffective lift. Above that range, the rotor is "overspeeding" and is providing ineffective lift. Additionally, a severe overspeed will cause failure of rotorhead components.
 
Scout, certainly take all the space you need to explain rotary wing aerodynamics, controls etc. Like others, I'm fascinated! I know (to the extent of being a private pilot in Cessnas/Pipers and USAFA Aero) fixed wing, but next to nothing on rotary! :)
 
Scout, certainly take all the space you need to explain rotary wing aerodynamics, controls etc. Like others, I'm fascinated! I know (to the extent of being a private pilot in Cessnas/Pipers and USAFA Aero) fixed wing, but next to nothing on rotary! :)

Well, that's a pretty big subject. What would you like to know?

The aerodynamics are similar in many ways, though obviously the rotary path of the wing makes things interesting.

The autorotational state is probably the most interesting from an aerodynamic standpoint. About 50% of the blade is turning the other 50%. 30% of the latter half is trying to slow the rotor, and 20% is stalling. The whole thing is like juggling while balancing on a beach ball, as raimius can attest. Practice makes better...not perfect, but better.
 
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Ghost Riders in the sky: They were the best and would go in under any conditions.

http://www.youtube.com/watch?v=RIrwELj87Z8

Lost one of them a while ago and he was one of the best. To all rotary pilots eveywhere. You are the greatest. Cash just makes it so much better.
 
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Have you ever seen someone pull a loop in a rotary? I know it’s not a direct question on aerodynamics of rotary but more of an indirect one. From what little I know of rotary it would be crazy to even think about trying it.
 
Have you ever seen someone pull a loop in a rotary? I know it’s not a direct question on aerodynamics of rotary but more of an indirect one. From what little I know of rotary it would be crazy to even think about trying it.

I watched the Red Bull demo team doing loops over the lake in Zurich last summer. It was insane. They had a Cobra, but I don't think they looped at all. The other two were tiny little helos which did loops, back flips, and other crazy stuff!
 
In short, yes. You can loop a rotary wing aircraft. The limiting factor is the rotorhead. A semi-rigid underslung rotor must always be "loaded" in terms of having positive G forces applied to it. Failure to load the rotor, combined with excessive cyclic input, can cause extreme blade flapping and mast bumping. Mast bumping is when the yoke contacts the mast, which can sever the mast and cause the rotor to no longer be an active participant in the flight experience.

A fully articulated rotor like an Apache is capable of low-G maneuvers. They improved the strap packs to the "fat boy" strap packs, so the blades can take a real beating.

See below. Note that the rotor remains loaded.

http://www.youtube.com/watch?v=us18o7qOXjI&feature=youtube_gdata_player

http://www.youtube.com/watch?v=OlDpBx8DC3k&feature=youtube_gdata_player
 
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The flares make special touch. The aerodynamics are cousins but the adventure is the same. John Miller looped a Pitcairn PCA-2 autogiro at the 1932 Cleveland air show.
 
Agreed the flares were a cool touch to the move. I've been in an fix wing and did a loop and the pucker factor was pretty high I could only imagine in a rotary! Seeing these and learning more about it makes me more disappointed that there weren’t any rotary flybys at the air show… I mean I’m on Fort Carson for Pete’s sake I can SEE them by their hangers! Oh well at least I got to sit them!
 
Agreed the flares were a cool touch to the move. I've been in an fix wing and did a loop and the pucker factor was pretty high I could only imagine in a rotary! Seeing these and learning more about it makes me more disappointed that there weren’t any rotary flybys at the air show… I mean I’m on Fort Carson for Pete’s sake I can SEE them by their hangers! Oh well at least I got to sit them!

It's not a rookie maneuver.
 
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