Well, they would louse thrust if they move backwards to fast. Loosing thrust is probably not their biggest problem in that case...

It felt like a stupid post when I posted it

The Huey, like the Chinook, certainly isn't 'immune' to VRS but it is far less susceptible as it has nice big blades rotating 'relatively' slowly compared to more modern aircraft such as the Hokum or Blackhawk.

This results in less powerful, less concentrated downwash, making it more difficult to enter VRS.

It's quite difficult to enter, even intentionally, requiring a prolonged vertical descent to establish fully.

- Horsey

The aerosft devs said its very difficult to enter a vrs, like an airplane that cant spin. This doesnt reflect as well on them as all planes can spin, some its just harder than others.

Anyway. So the huey is difficult to put into vrs? Challenge accepted

I don't think the relative speed of the blades makes much difference to Vortex Ring, I would agree that all helicopters are susceptible to it, but IMHO the rotor speed has little effect. The key rules of thumb for Vortex Ring are power applied, low airspeed and high rate of descent....and yes it does need a little while to develop.

Until 2006 I flew the Merlin HC3, which is a modern helicopter with 'BERP' blades that create enhanced lift, but even this would enter Vortex Ring at, I seem to remember, less than 5 kts airspeed and around 1200' ROD. I only did this in the simulator as obviously we weren't allowed to intentionally do it, but it was bloody difficult to enter!

I also flew the Puma HC1 until recently and have been in fully developed Vortex Ring...once...and never again. There are lots of myths surrounding Vortex Ring and it was widely believed by many at the time that the Puma was not susceptible, however I was given a demonstration many years ago by a very experienced instructor that was supposed to have just been 'incipient' Vortex Ring and went 'full'. We were simply meant to feel the ac get all mushy and wallowy, then push forward on the cyclic to gain airspeed to recover.

I remember we could only get into Vortex Ring by flying backwards (airspeed negative of course) and the aircraft starting getting 'mushy' at around 800' rate of descent at around 6000' altitude, the time interval between 'mushy' and 'full entry' was about 0.01 of a second! The first thing that happened was the ac instantly dropped the nose from about 10 degrees nose up to 90 degrees nose down, as the nose fell the ac rolled through 180 degrees or more and we recovered after some difficulty at around 1800' altitude with 30 kts airspeed, the ball all the way out to one side, about 45 degrees left wing low and still in a descent. It was genuinely horrible and without sounding melodramatic I thought I was going to die! After that incident, all Vortex Ring 'familiarisation' was done in the Simulator.

Hope that enlightened and didn't bore too much

Gosh, that put me off.
Many congrats for your survival! :O
No jokes.

Don't be put off Komemiute ... I will need a wingman, try the shark first ... it will be easier to fly than the uh-h1



Tempus ...aka Baldric

LOL! You just lifted me off me feet! Sure thing then. If we could just convince Percy PErcy to join in too...

Aaaaaand we're ready...

You should always listen to THE VOICES Rusty when they are trying to tell you that something is fundamentally wrong, or deeply flawed. THE VOICES are wise, and know many things.

Sometimes I disobey them too.....and they punish me by making me post absolute bollocks on SimHQ. It can happen to us all. Clear the murky fishbowl of the mind, and Be like water. Or was it Marzipan. One or the tuther.

The size and intensity of the downwash is an important factor which is affected by, among many other things, the rotor diameter and rotor speed.

The pilot can't adjust these (much) so they are usually excluded from VRS discussion in favour of factors which the pilot can affect, but they help explain why one type may be more or less susceptible to VRS.

Your VRS story sounds as if it also involved some RBS. Did it occur as you introduced collective to develop the VRS?

- Horsey

I am very excited about this Huey!! I have been setting up missions in black shark, troops and light aaa in a town, and the shark outfitted with dumb rockets only-- then i turn off all the blue buttons down low to the right. Hope the huey is like this ..fun.

I'd be more excited with a Loach... that's a sweet little chopper

[quote=WarHorsey

Your VRS story sounds as if it also involved some RBS. Did it occur as you introduced collective to develop the VRS?

- Horsey [/quote]

Hello mate, VRS requires a sustained descent so we had already brought in power just after initial entry and effectively held the collective in place with moderate power on. The tipping point was when the actual rate of descent went over 800' per minute and we then went out of control. One of the effects of full VRS is some loss of control...hence the 'mushiness' I talked about earlier in incipient VRS, but this was almost total loss of control

Retreating Blade Stall is something different though, it is typically found at very high forward air speeds, high weights and abrupt manouevres, rather than in a sustained descent from the hover. I have only encountered this in the Simulator but it was fairly unpleasant in there