Can someone explain this?
#21
12-16-2007, 08:52 AM
#22
12-16-2007, 10:57 AM
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RE: Can someone explain this?
ORIGINAL: isolated1523
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
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
Just like the flaps on planes. Slows down the decent. I remember watching the history channel on of it.
That's not the reason why its there but they can use it.
From take off they can tilt the blades for more lift or less for floating.
#23
12-16-2007, 10:59 AM
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RE: Can someone explain this?
#24
12-16-2007, 11:01 AM
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RE: Can someone explain this?
Pitch Housing. The pitch housing permits blade pitch changes in response to flight control movements transmitted through the swashplate. This is made pos- sible within the four pitch housings by V-shaped stainless steel strap assemblies that are able to twist and flap to permit blade feathering and flapping. Cyclic and collective stick inputs are transmitted to the pitch housing horns by pitch links attached to the swashplate. Feather bearings are installed inboard on the pitch housing to allow vertical and horizontal loads to be transferred from the pitch hous- ing to the hub. Centrifugal loads are transmitted by each strap assembly to the hub
#25
12-16-2007, 11:04 AM
#26
12-16-2007, 11:10 AM
RE: Can someone explain this?
ORIGINAL: randyjoy
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!!
ORIGINAL: Asmittie84
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).
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).
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!!
Pilot...rider...
I've been up in a copter one time as a kid, my dad and I saw a guy just down our old street in a vacant field.
"Helicopter rides...$20".
This was back in the 70's so keep that in mind.
I don't remember the exact model or anything, but I do remember there were no doors on it.
I talked my dad into letting me sit nearest the outside...3 seater.
I remember tilting over our town at the time, the only thing holding me in a seat belt/harness type thing, and being about
1500 feet in the air...I could feel the possibility of slipping liquid like through the straps and falling.
Just my over-active imagination of course. I can't really turn into liquid. Honest. (Ba dum splash)
Seriously,...
That was one of the scariest, but of course cool and fun rides I have ever had. I laughed the whole time.
Taking off was a rush...the ground just falling away from me.
#27
12-16-2007, 12:20 PM
RE: Can someone explain this?
I'm actually a Crewchief / Flight Instructor on UH-60 Blackhawk helicopters. The one in this video is a Mi-24 "Hind". Along with what our forum helo pilot said, you can land a helicopter without power by performing an auto, but the main rotor would be spinning no matter what. Even if the main rotor was not spinning and the tail rotor was, the torque from the tail would be yawing the helicopter out of control. It had to be frame rate and rotor RPM being in sync on the camera or just a clever little trick where it's just a small model with working props dangling on a string with helo noise in the background. Funny though!
#28
12-16-2007, 02:24 PM
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RE: Can someone explain this?
ORIGINAL: bmg velocity
I don't remember the exact model or anything, but I do remember there were no doors on it.
I talked my dad into letting me sit nearest the outside...3 seater.
I don't remember the exact model or anything, but I do remember there were no doors on it.
I talked my dad into letting me sit nearest the outside...3 seater.
You probably flew in a Bell 47 - like they used on MASH. Three across, big bubble, removable doors. My very first instructional flight was in a 47. Workhorse, lots of 'em still around, standard engine so they are pretty cheap to run.
I don't get to fly as much as I used to, I keep threatening to go rent one for a weekend, but I could almost buy a new bike for the cost!!
Luckily, closest thing to flying is my 954.
#29
12-16-2007, 03:27 PM
RE: Can someone explain this?
ORIGINAL: randyjoy
Nothing like helicopters.
You probably flew in a Bell 47 - like they used on MASH. Three across, big bubble, removable doors. My very first instructional flight was in a 47. Workhorse, lots of 'em still around, standard engine so they are pretty cheap to run.
I don't get to fly as much as I used to, I keep threatening to go rent one for a weekend, but I could almost buy a new bike for the cost!!
Luckily, closest thing to flying is my 954.
ORIGINAL: bmg velocity
I don't remember the exact model or anything, but I do remember there were no doors on it.
I talked my dad into letting me sit nearest the outside...3 seater.
I don't remember the exact model or anything, but I do remember there were no doors on it.
I talked my dad into letting me sit nearest the outside...3 seater.
You probably flew in a Bell 47 - like they used on MASH. Three across, big bubble, removable doors. My very first instructional flight was in a 47. Workhorse, lots of 'em still around, standard engine so they are pretty cheap to run.
I don't get to fly as much as I used to, I keep threatening to go rent one for a weekend, but I could almost buy a new bike for the cost!!
Luckily, closest thing to flying is my 954.
All kinds of memories flooding back now about that flight...
Thanks.
#30
12-16-2007, 03:32 PM
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