409 KPH

[Warbird_242]

I'm sure there would be some kind of structurally damaging vibrations as the blades approached the sound barrier (at Mcdr, critical drag rise mach no.), and this rapid (very rapid) rise in drag, with the corresponding changes in dynamics across the disk of the rotor (regardless of the fact that it isn't needing to generate lift in a vertical dive)....well, I don't think it would survive that, given what I've seen of a fling-wings propensity to disintegrate at the slightest hint of anything out of the ordinary. And that's not even mentioning bits (antennae, panels, pylons etc) being ripped of the chopper just due to dynamic pressue at those airspeeds, way beyond design limits. If they could do it, they would have (by strapping jets to a chopper, and they never managed to get that right, even though they tried).

 

 

Exactamon

 

Thankyou sir :D

[26-J39]

Obviously these speeds are ridiculous, i do not claim it to be a realistic dive speed... that is not my intention ;) Do we really need to beat the reality monkey? :P

[ARM505]

Not at all :) - I'm impressed you got it to go so fast. I'm just saying that I think you caught ED a little unawares, in a way - I bet they didn't expect to see anyone do that in a hurry, and thus didn't model that quite as brilliantly as the rest!

 

Or, to put it another way, I don't think ED modelled compressability effects across the blades (this is taking a wild guess). Basically, they've probably just created a zone of conditions that create 'overspeed' symptoms. Almost a 'canned' effect. This isn't a dig at the modelling - the chopper is supposed to be flown low and slow, where high mach numbers normally don't feature. A perfectly placed use of a 'canned' effect IMHO, instead of doing pointless calculations for something normally irrelevant. It's a guess, but hey!

Edited October 9, 2009 by ARM505

[Warbird_242]

I suppose we have to drag the ole' DCS thing up again :D

 

Digital COMBAT Simulator

 

A Ka-50, even if it could, would never attempt to reaach those speeds if it had an intention of utilizing weapons - the drag might actually rip the Vikhirs off.

 

So don't give ED any black marks because it would be useless to model these sorts of speeds - and it helps in competitions like this :D

[26-J39]

Good comments guys :) Cheers..

It's all just a good laugh really.. :D

All the best!! :thumbup:

[topol-m]

BTW what`s the record speed achieved in LOFC? :pilotfly:

[159th_Viper]

BTW what`s the record speed achieved in LOFC? :pilotfly:

 

Not by any means claiming a record - just FYI :)

 

SU-25T Quick-Start Mission:

 

RTB - Wind 0 m/s

 

Sustained Level Flight - Not from Dive:

 

 

 

[AussieFX]

For level flight:

"Lynx helicopter, registered G-LYNX, flew a 15km course across the Somerset Levels at 500 ft on a calm hazy evening back in 1986 with Westland Chief Test Pilot Trevor Eggington at the controls and Derek Clews, Flight Test Engineer alongside. The average speed achieved over two runs was 249.1 mph (400.87 kph), beating the record held by a modified Mil “Hind” helicopter by over 20 mph (32 kph)."

 

I do not think anyone has recorded a max speed in a dive!

Sikorsky and some private company in the states are working on a Seahawk with the anti torque rotor removed and replaced with a weird looking ducted fan in a shroud so it can give anti torque as well as thrust. I think in testing they got it to somewhere near 230kts and said 250kts "might" be possible. It was all done in level flight but it's in the very early testing days.

There was all sorts of talk such as adding a 3rd engine (T700??) etc. I have no idea if they're still working on it however.

 

I will try to dig it up.

http://www.encyclopedia.com/doc/1G1-118446601.html

 

picture.

http://forums.eagle.ru/attachment.php?attachmentid=32205&stc=1&d=1255348878

 

Here's a video of the first flight test. I was wrong they have only got it to 170kts which isn't bad in itself as a mate of mine was a hawk driver and he said the best he got out of his machine was 130KIAS and it was trying to shake itself to bits.

The wings are an interesting addition, probably so they can bottom the collective at high speed.

It sounds like a PC9. :)

Edited October 12, 2009 by AussieFX
Finding links

[26-J39]

YoYo is on holiday at the moment. I am sure he will give an explanation when he returns!

:music_whistling:

[Yo-Yo]

YoYo is on holiday at the moment. I am sure he will give an explanation when he returns!

 

What's the QUESTION?

 

I do know that if rotor rpm is lowered to avoid high M number on the blades, if the rotor is unloaded to avoid excessive flapping, the helicopter can be accelerated to high speed because THERE ARE no physical reasons to prevent it. Moreover, the aerodynamics for Ka-50 airframe model does not use data for high M as plane aerodynamics, because it's not necessary for the speed the helicopter normally flies at.

 

I don't exclude that real helicopter could be accelerated in such manner but I am sure that nobody in RL will test it without "RESPAWN" button on pilot's chest.

 

And, by the way, this ability is not useful in RL, because while recovering nobody knows if it will be successful.

[Distiler]

Holy batman necro FTW! o_O

 

Yo-Yo you're needed in another thread: http://forums.eagle.ru/showthread.php?t=56997

[26-J39]

I appreciate your response Yo-Yo.. Thank you.. :)