they filled the gas tank with redbull.....and it gave it wings!

 

Well we have a couple of smart people on here. Its frame rates. They matched the camera with the rotors.



Watch a Youtube video of someone recording a TV or PC monitor. Notice how the pc monitor flickers/lines going down. The camera and monitor aren't running at the same frame rate or Hertz.

 

I'm a helicopter pilot - the frame rate answer is correct. I've got videos of me flying a Hueydoing the same thing.

For future use, one of the giveaways is that the tail-rotor is spinning. The tail and main rotors are physically connected to each other - when the main spins (either by engine or autorotation) the tail spins too. Most helicopters have a 3:1 up to a 6:1 ratio of tail to main (the tail goes faster since it's smaller. The tips also exceed the speed of sound, which is where most of the noise actually comes from).

So, the main rotor HAS to be spinning with the tail, and the tail is going anywhere from 600 to 3000 rpm, depending on the craft.

 

Someone hit the peace pipe a little too soon.

Randyjoy. Maybe you can answer this for me. I've heard that if a Helicopter say runs out of fuel. That it can actualy land (Not at a gentle speed but not at free fall). Which a friend's friend isa Paramedic on lifeflight who's helicopter crashed because offuel issue. The pilot did realize it and got the Helicopter close but it still crashed. Everyone lived which was I think the first time out of 3 lifeflight crashes that anyone survived. Not too sure I'll have to check again.

 

I'll try to make it short, but the answer is a qualified yes.

As a helicopter loses drive power and begins to fall, the wind rushing through the main rotor makes it spin, just like the twirling paper rotors we made in school do. You do a controlled fall, at several hundred feet per minute, as you approach the ground you flare (which reduces forward speed and downward fall. It also eats up all the stored energy in the rotor). You should now be going about 5 mph and about 5 feet off the ground. Plop! You're down.

To get a private pilot license, you have to do an autorotation landing to 5'; to get commercial, we did a full down. The examiner would roll off the throttle, yell "Engine Failure" and away we went. (My instructor did this repeatedly, too...one time I autorotationed into a clearing in a grove of trees, we chatted about the almost full down landing, and when I popped back up, there were a bunch of fire trucks, police,and ambulances heading toward us...oops, we got out of there!!!)

It will also work in a hover at about 20' or less by simply yanking the rotor pitch control up right before you hit. Also, the skids/wheels have a give to absorb some of the impact.

The problem is there's a curve that it won't work in - you can't transition from powered flight to autorotational flight. You have to have altitude (say 400' or more) or speed (say 80 knots at 25') or a combination. So, at 100' in a hover, if I have a failure, I can't "transition" and I hit hard. (The numbers are averages, different craft have different specifications / speeds / altitudes).

We push the envelope all the time, hoping we won't have a failure in the "gray area". What's the point and having a cool helicopter if we have to fly it like a plane!!

 

Autorotation like Randjoy mentioned. The main rotors can still turn when out of fuel and can cause slight drag to slow decent. But Randjoy can probably give a better explaination then I...

 

Thanks rand. From what I heard about my paramedic buddy is that they dropped off a kid at a hospital somewhere in northern North Carolina. Before returning to flight the Pilot forgot to turn something on/off(Not sure which). Or didn't do a proper inspection. Then in flight the pilot noticed the problem. So I'm not sure how high off the ground they were when they crashed. Being he noticed the problem in flight I assume the pilot tried to get to the ground quickly. It happend about 5miles from the hospital so maybe that can clue you in on what happend. But being a lifeflight helicopter I assume it's probably one of the baddest of the bad helicopters out there.

Helicopters are freaking cool. I got to ride in one when I was young and in boyscouts. I wish I could again.

 

I know the Apache/Longbow has the ability to tilt the main blades. Helps with lift and something else. It can also aid in landing when the rotor stops.

 

Randyjoy is right on the money. Probably the only thing i would add is that falling at several hundred feet a min is actually pretty hopeful. In the TH-67 (bell 206) that i just finished in, it was nothing to see 1000-1500 feet/min descent. In the OH-58D that i'm transitioning into, it's even faster due to weight. But it's fun, as crazy as it sounds. One of those adrenaline rush things.

Rangerscott--not sure what your getting at with the longbow...all helicopters have the ability to "tilt" their blades--it's how controlled flight is possible.

Oh yeah---did i mention how much i love flying??? lol

-Adam

 

I used to do a lot of photo flights around the DFW metroplex, and we'd land at all kind of places - shopping centers, restaurants, convenience stores, etc. Flying helicopters is way better than fixed wing, IMHO.

I was being "covert" with the "several" hundred feet per minute; everything I've ever flown is right up in the range you mentioned. Ever fly a Robinson R22? Real twitchy, but neat, but 1500 fpm every time on auto. Since we usually flew at 400-500 agl, we were on the ground in 20 seconds.I like the R22 since I can rent one for only $175/hr and take a buddy out flying. Bell 206's cost me $600/hr.

My 954 is the closest thing to flying!!