Vortex Ring / Settling with power (Merged)
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Add terrain into the VRS situation and sometimes going straight ahead might not be the best choice is what I am suggesting.
What is important is understanding VRS and how it affects aircraft performance....the risk it poses....and the quickest way to identify the onset and perform immediate effective recovery techniques.
Knowing how the flight control's effectiveness is affected is part of that.
What is important is understanding VRS and how it affects aircraft performance....the risk it poses....and the quickest way to identify the onset and perform immediate effective recovery techniques.
Knowing how the flight control's effectiveness is affected is part of that.
Vuichard's technique was to make a recovery easier for situations where there was little altitude or suitable terrain to get the nose down.
No technique will make any difference to accidents like this where the cause is PPP.
Add terrain into the VRS situation and sometimes going straight ahead might not be the best choice is what I am suggesting.
What is important is understanding VRS and how it affects aircraft performance....the risk it poses....and the quickest way to identify the onset and perform immediate effective recovery techniques.
Knowing how the flight control's effectiveness is affected is part of that.
What is important is understanding VRS and how it affects aircraft performance....the risk it poses....and the quickest way to identify the onset and perform immediate effective recovery techniques.
Knowing how the flight control's effectiveness is affected is part of that.
Happy landings
VF
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Wes Prouty explained this in an issue of Rotortales many many years ago......VRS requires 3 things, relatively high rate of decent ( most modern helicopters about 500') partial power ( can't be in VRS in an autorotation) and low airspeed ( less than translation). Only 2 ways out, moving out of the "bubble" or full down collective and entering autorotation (usually not an option). What you do with the flight controls to get you out of the bubble will depend on many factors, but in my experience lowering the collective as much as possible and forward cyclic is the best muscle memory method.
SWP is simply not enough power ( lift) available for the flight condition, hot/ high for example.
SWP is simply not enough power ( lift) available for the flight condition, hot/ high for example.
This accident, and most others, have nothing to do with deeply developed VRS or anything that could be attributed to it.
Vuichard's technique was to make a recovery easier for situations where there was little altitude or suitable terrain to get the nose down.
No technique will make any difference to accidents like this where the cause is PPP.
Vuichard's technique was to make a recovery easier for situations where there was little altitude or suitable terrain to get the nose down.
No technique will make any difference to accidents like this where the cause is PPP.
Happy landings
So true Bell Ringer, nothing will save Your arse when in PPP. But You are ignoring the fact that Vuichard technique DOESN'T work in VRS; please don't take my word for it...go prove it for Yourself! & be sure You are fully established in VRS when testing this concept!
Happy landings
Happy landings
Recovery is a poor substitute for prevention.
Wes Prouty explained this in an issue of Rotortales many many years ago......VRS requires 3 things, relatively high rate of decent ( most modern helicopters about 500') partial power ( can't be in VRS in an autorotation) and low airspeed ( less than translation). Only 2 ways out, moving out of the "bubble" or full down collective and entering autorotation (usually not an option). What you do with the flight controls to get you out of the bubble will depend on many factors, but in my experience lowering the collective as much as possible and forward cyclic is the best muscle memory method.
SWP is simply not enough power ( lift) available for the flight condition, hot/ high for example.
SWP is simply not enough power ( lift) available for the flight condition, hot/ high for example.
SWP; that's a totally different story...pull more power (if You have it without cooking the donk) otherwise same as above pole fwd & fly away!
Happy landings
Cheers
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Bang on Mate.....If my old memory serves me it's 300fpm. But, from experience You need to have way higher ROD, more like +1,000fpm to go VRS! I don't go with lowering the club....just pole forward with power on. That's one less thing to do & I feel You get into cleaner air much faster, powers already on so away You go! The key is tilting the disc, with power on Your pulling clean air into the problem the moment You pole fwd!
SWP; that's a totally different story...pull more power (if You have it without cooking the donk) otherwise same as above pole fwd & fly away!
Happy landings
SWP; that's a totally different story...pull more power (if You have it without cooking the donk) otherwise same as above pole fwd & fly away!
Happy landings
To get into VRS you need to be travelling downwards at over half the speed of your downwash and an S61 has far more than 600'/min downwash, more like 2000'/min.
It is all about disc loading - older helicopters had low downwash speeds because engine power was lower and the rotor had to be bigger.
Modern helos have very powerful engines and smaller rotors for the same or increased AUM.
Nick Lappos published a RoD vs Fwd speed diagram for VRS produced, I think, by the US Army. The VRS boundary was related to downwash speed - you needed 0.6 to 0.8 of your downwash speed to catch it up enough to start to ingest it.
https://www.rotorandwing.com/2011/11...wash-velocity/
It is all about disc loading - older helicopters had low downwash speeds because engine power was lower and the rotor had to be bigger.
Modern helos have very powerful engines and smaller rotors for the same or increased AUM.
Nick Lappos published a RoD vs Fwd speed diagram for VRS produced, I think, by the US Army. The VRS boundary was related to downwash speed - you needed 0.6 to 0.8 of your downwash speed to catch it up enough to start to ingest it.
https://www.rotorandwing.com/2011/11...wash-velocity/
well as a demo to students in an old heli ( S 300C ) fly downwind at 17"map trying to hold height She looses translational lift at around 20 kts, ROD now about 500 ft plus.Now in IVRS, Pull power up to 24 inches and guess what aircraft climbs back up again. I have to have more than about 800 ft a min for the aircraft not to be able to pull herself out of the situation
VF,
Where did I ever say I endorse the Vulchard Method?
What I have stated is an opposition to limiting VRS recovery to exactly one single method as you seem to be saying.
That kind of mindset....one size fits all kind of thinking.....is not the way life works in flying helicopters.
At altitude well clear of terrain you might be technically correct but when close to the ground you might just want to go towards a particular direction that might just in fact be not straight ahead.
You fly in some mountains....and thus probably understand there are times there might be lots of air under you to one side and lots of rock ahead and on the opposite side to the valley floor.
Would you not want to go towards the valley floor rather than the Ridgeline?
Where did I ever say I endorse the Vulchard Method?
What I have stated is an opposition to limiting VRS recovery to exactly one single method as you seem to be saying.
That kind of mindset....one size fits all kind of thinking.....is not the way life works in flying helicopters.
At altitude well clear of terrain you might be technically correct but when close to the ground you might just want to go towards a particular direction that might just in fact be not straight ahead.
You fly in some mountains....and thus probably understand there are times there might be lots of air under you to one side and lots of rock ahead and on the opposite side to the valley floor.
Would you not want to go towards the valley floor rather than the Ridgeline?
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Originally Posted by [email protected]
To get into VRS you need to be travelling downwards at over half the speed of your downwash and an S61 has far more than 600'/min downwash, more like 2000'/min.
It is all about disc loading - older helicopters had low downwash speeds because engine power was lower and the rotor had to be bigger.
Modern helos have very powerful engines and smaller rotors for the same or increased AUM.
Nick Lappos published a RoD vs Fwd speed diagram for VRS produced, I think, by the US Army. The VRS boundary was related to downwash speed - you needed 0.6 to 0.8 of your downwash speed to catch it up enough to start to ingest it.
https://www.rotorandwing.com/2011/11...wash-velocity/
It is all about disc loading - older helicopters had low downwash speeds because engine power was lower and the rotor had to be bigger.
Modern helos have very powerful engines and smaller rotors for the same or increased AUM.
Nick Lappos published a RoD vs Fwd speed diagram for VRS produced, I think, by the US Army. The VRS boundary was related to downwash speed - you needed 0.6 to 0.8 of your downwash speed to catch it up enough to start to ingest it.
https://www.rotorandwing.com/2011/11...wash-velocity/
Anyway, this has been beat to death......let it die.
Size and gross weight have no bearing on VRS, actually the 2 times I have been in it it was both times in an empty a/c.
It's not about the size and gross weight of the helicopter, it is disc loading which is AUM vs size of the rotor.
I am just passing on information from the likes of Mr Lappos who generally seems to know his way round a helicopter
If you don't like or believe it, that is up to you but that doesn't make it not true.
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I think some of you are forgetting that a roll command would respond faster than a pitch (nose down) command. Therefore jumping sideways with pedal assist would be quicker than jumping forward when you have no airspeed!
Unless you encounter VRS from the hover in zero wind in a vertical descent or are downwind, chances are you will have some forward airspeed, even if it doesn't register on the ASI so forward will be better and quicker.
The lateral control input might change the disc attitude slightly quicker than forward but you still have the same amount of inertia in the aircraft to move and you are trying to drag it sideways through the air.
The lateral control input might change the disc attitude slightly quicker than forward but you still have the same amount of inertia in the aircraft to move and you are trying to drag it sideways through the air.
Good luck Mate & Happy landings
VF