Helicopter Quest for Speed, page 1

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Topic started on 28-9-2010 @ 06:33 PM by PopeyeFAFL

For those of you who know a little bit on helicopter, you know that there was always a limitation in term of speed (related to the speed at the tip of the blade compound with the forward flight speed).

Several attempts has been try throughout the years, to lift that speed barrier, most recently:

Bell Osprey V22 Tilt Rotor (the whole concept was not just for speed) and it's commercial counterpart the BA609.

Sikorsky X-2.

And as of September 27, 2010 Eurocopter unveil the H3 concept.

The BA609 is supposed to cruise at 260 knots.

The Sikorsky X-2, just reach 250 knots.

The Eurocopter H3 is targeted for 220 knots.

So which solution do you think will win and open up the speed at a reasonable price & complexity?

Links:

H3 including Youtube video:

defense-update.com...

Sikorsky X-2:

en.wikipedia.org...

BA609:

en.wikipedia.org...

There is a rumour that Bell Helicopter is working on "Project X" (no one knows what it is, company private) but I doubt that Bell will depart from the Tilt-Rotor knowing the long time involvement in Tilt-Rotor technology.

Now if that "Project X" is just a better and improved conventional helicopter, it will suffer from the speed limitation.

Please shed a light on this.

reply posted on 28-9-2010 @ 06:39 PM by CX

I'm no heli expert, but when we were using the Lynx every day in S.Armagh, we were told it was the fastest heli around.

Is that not the case anymore then? Or was it ever?

CX.

reply posted on 28-9-2010 @ 06:50 PM by PopeyeFAFL

reply to post by CX

From Wikipedia:

In 1972, a Lynx broke the world speed record over 15 and 25 km by flying at 321.74 km/h (199.92 mph). It also set a new 100 km closed circuit record shortly afterwards, flying at 318.504 km/h (197.91 mph).

Even at 318 km/h (172 knots), this is still a good 50 to 90 knots slower then the new proposals.

reply posted on 28-9-2010 @ 07:14 PM by rebeldog

reply to post by PopeyeFAFL

dude, you are way off-------

airwolf is the fastest chopper..

reply posted on 28-9-2010 @ 07:56 PM by tungus

reply to post by PopeyeFAFL

Looks very cool, I watched the video.

Here are some considerations that I can think of:

I guess it is fine as long as it doesn't make hard left/right turns.
Also, instead of using some of the available power for one tail rotor,
the engines now has to feed two rotors.

There is a condition called retreating blade stall.
In forward flight of a helicopter one half of the rotor disc goes against the airflow and the other goes away from it, or retreats from the airflow. This produces a differential in the lift of the disc (called dyssimmetry of lift) and is compensated by the blades flapping up (on the advancing side of the disc) and down (on the retreating side of the disc), which equalizes the lift and the helicopter is level. No action is required from the pilot. Things change when the forward airspeed increases.

As the speed increases the retreating blade reaches critical angle of attack and stalls. When that happens the blade drops low, is no longer able to produce lift and the helicopter begins to tilt to that side.

Now with propellers on each side, when that blade drops low either because of the retreating blade stall or turbulence or both it may strike the propeller in which case it will destroy the main rotor blade and the said propeller. In addition of dropping like a stone, the helicopter will also turn to one side because the other propeller will be intact.

The retreating blade stall doesn't just happen instantaneously, there are signs when this condition develops and I am sure the pilots are trained for that.

These are my concerns, though.

YouTube Link

edit on 28-9-2010 by tungus because: clarity

reply posted on 28-9-2010 @ 08:20 PM by shaolin_dragon

Originally posted by rebeldog
reply to post by PopeyeFAFL

dude, you are way off-------

airwolf is the fastest chopper..

i dont care who ya are...thats funny!!

I'm a massive airwolf fan, and i totally agree. That sleek black vision of loveliness kept me company through many a weekend night!! And there is not a single chopper out there that can match her in agility, speed and armament...unless you team up with Blue Thunder!!

reply posted on 29-9-2010 @ 01:08 PM by Luke.S

I am really hoping someone will decide to wedge some jet engines with afterburners into a B222. And then paint it black and white. Then put some chain guns which can be retracted and custom versions of some missiles (how else will we get the ADF pod) she also needs to do mach 1+. However it could work by having the onboard computers (which would now be miles smaller than in the program and a lot lighter) disengage the rotors and balance the speed so that the aircraft can do mach 1 without snapping off the rotors. I think it should be possible

So basically we need a modern version of my avatar. But gotta be a B222. Can't beat the 222, soo two blades ftw. Oh and it needs to have the howling sound and the rotor sound of airwolf.

edit on 29-9-2010 by Luke.S because: (no reason given)

reply posted on 29-9-2010 @ 01:47 PM by chopperswolf

put a wing on the retreating blade side, with an internal ballast that adjusts left or right to maintain center of gravity during high speed flight. the rotor acts as a wing while the wing acts as a wing, letting the ballast equalize cg. one propeller with variable pitch blades, mounted conventionally in an engine nacelle could be used to control rotor torque as well as provide high speed forward propulsion. it would look funny, but the theory is sound.you could probably design the rotor to disengage at high speed to act as a gyrocopter rotor, and use the outboard engine only during high speed flight.

edit on 29-9-2010 by chopperswolf because: (no reason given)

reply posted on 29-9-2010 @ 02:04 PM by JIMC5499

reply to post by Luke.S

If you do all of that, it should be able to carry enough fuel to fly for 8 or 9 seconds.

reply posted on 29-9-2010 @ 02:51 PM by paraphi

The tile of the thread is “Helicopter Quest for Speed”

Define what a helicopter actually is because I think a tilt rotor aircraftt like the Bell/Agusta BA609 or the Boeing V22 are not helicopters.

The title of the thread should be “Tilt Rotor Quest for Speed” or “Things with Big Rotors Quest for Speed”

Definition 1
Definition 2 (from Wikipedia where everything is simple)

The fasters real helicopter is the Westland Lynx

Regards

reply posted on 5-10-2010 @ 01:28 AM by Shmuel_invincible

reply to post by PopeyeFAFL

pretty much all helicopter's (possibly excluding the v22 / ospree) should be banned as once the engine fails or a rotor breaks there is almost no change of survival except if your altitude probebly at least 5000 feet enough and have enough time to strap on a chute jump out open and deploy. And yes the standard autorotation is in most cases not viable for safe landing...

reply posted on 11-10-2010 @ 12:30 PM by Luke.S

Originally posted by Shmuel_invincible
reply to post by PopeyeFAFL

pretty much all helicopter's (possibly excluding the v22 / ospree) should be banned as once the engine fails or a rotor breaks there is almost no change of survival except if your altitude probebly at least 5000 feet enough and have enough time to strap on a chute jump out open and deploy. And yes the standard autorotation is in most cases not viable for safe landing...

You really don't have a clue. If an engine fails auto rotation is a highly successful method of landing due to the fact that as long as you keep the RPM up the rotors provide enough lift to land without damaging the aircraft. If the rotors break of course you are screwed. But rotors are extremely strong so it is likely down to pilot error if the rotors snap off.

reply posted on 11-10-2010 @ 02:11 PM by proteus33

want a helicopter to break sound barrier slap a huge rocket on its arse but be prepared for its destruction

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