How do helicopters fly without wings ?

[UM-Bot]

A look at how helicopter rotor blades make it possible to fly vertically in to the air.

 

[+and-then]

Helos actually DO have "wings", it's just that they aren't fixed.  I used to watch Coast Guard helos, BIG ones, use the rotors to make unpowered landings in the Gulf near my home.  The "auto-rotating" blades form a kind of a drag that's like a parachute.  Remember the old WWII movies where a bomber loses engine power and the crew makes the prop freeze in place?  It's the same effect.

[Timothy]

On 10/12/2017 at 10:10 AM, and then said:

Helos actually DO have "wings", it's just that they aren't fixed.  I used to watch Coast Guard helos, BIG ones, use the rotors to make unpowered landings in the Gulf near my home.  The "auto-rotating" blades form a kind of a drag that's like a parachute.  Remember the old WWII movies where a bomber loses engine power and the crew makes the prop freeze in place?  It's the same effect.

Exactly, annoying when people say they don't have wings. Autorotation is extremely cool, it kind of goes against initial logic that you would be able to land a helo without power.

I've never seen it in person, it would be impressive. Plenty of scope for disaster.

My only exposure to it is piloting choppers on the ArmA 2/3 computer games, and that's hard enough.

[+and-then]

The first time I saw one of these big helos autorotate down to the water, I thought I was witnessing a crash    After it sat for a few minutes and then it powered up and took off, I was amazed!

[Timothy]

14 minutes ago, and then said:

The first time I saw one of these big helos autorotate down to the water, I thought I was witnessing a crash    After it sat for a few minutes and then it powered up and took off, I was amazed!

Would be scary to watch until you knew what was happening!

[RoofGardener]

On 10/12/2017 at 0:10 AM, and then said:

Helos actually DO have "wings", it's just that they aren't fixed.  I used to watch Coast Guard helos, BIG ones, use the rotors to make unpowered landings in the Gulf near my home.  The "auto-rotating" blades form a kind of a drag that's like a parachute.  Remember the old WWII movies where a bomber loses engine power and the crew makes the prop freeze in place?  It's the same effect.

It IS an interesting feature, isn't it ? They don't form a parachute, however. What I believe happens is that the pilot reverses the pitch of the blades, so the air rushing past the rotors starts to spin them (and the engine) around. At the last minute, the pilot then restores the rotor pitch.

The motor - whilst not powered - is now spinning furiously, so it spins the rotors. For a while.

With the rotor pitch restored to "lift" mode, they now "bite" and start lifting the helicopter (or at least retarding its fall). But only for as long as the momentum in the spinning engine lasts !