PPRuNe Forums - View Single Post - Vuichard again
Thread: Vuichard again
View Single Post
Old 6th Apr 2022, 15:32
  #68 (permalink)  
Rotorbee
 
Join Date: Jul 2004
Location: Europe
Posts: 433
Received 20 Likes on 12 Posts
Oh my, helonorth, now you are reading something I never wrote. I always said, that if the method get’s you out of trouble, use it (as does airbus, but they caution you to use it in certain scenarios only). The points most of us are making, are:

a. Nobody has flown independent flight tests with all the necessary instrumentation to lock at all the aspects AND PUBLISHED THE FINDINGS IN A SCIENTIFIC PAPER. For example, some of us are concerned, that the blade flapping, already excessive in VRS (the aerodynamics are really a mess and not completely understood to this day), might become even worse and the blades might get too close to the tail boom in that regime.

b. That in case you have SWP and not (yet) VRS, you make it even worse with the Vuichard method. The classical method get’s you out of both. The Vuichard method is really not a good idea if you have no more power left. (Yeah, I know, bad planning if you don’t have always some power left)

c. As Robbie said from his own experience, when you get in there, especially as a relatively new pilot, the stress level might be too high, to do all the mental decisions in a short time. The classical method is so easy and logical and just works, too. Even experiences pilots can be overwhelmed with everything else going on. For example in one of the accidents, the pilot tried to make a precautionary landing because of some funny noises from the engine or the gearbox. In that case, all of us have limited mental capacity and must rely on as simple procedures as possible. When he could not control the descent rate, he flew straight and touched down hard, but stayed upright. Imagine flying sideways with a possibly broken engine close to the ground.

d. If you use what you learned as you describe it, in an H120, H125, H130, H155, H160, H175, H215, H225 or anything MiL, you’r in for a surprise, because you would have pushed the wrong pedal. And since many pilots switch between types of helicopters, every time they would have to think about which pedal to push. That’s not something you want to do in a high stress situation. I wonder what the KA-32 does.

e. In some some aerial applications, like sling loading, you create a whole bunch of new problems going sideways (and the load the other way).

f. The whole VRS danger has been blown out of proportion. There aren’t thousands of fatal accidents from VRS. There are thousands of accidents from SWP, but that is not a problem Vuichard’s method solves. On the contrary, it might make it worse.

That’s what we are discussing here. While I and others (even Crab is open to it, I think) accept, that you can get out of VRS faster, there are other factors to consider, which makes us question the viability Vuichard’s method, not a least the problem with the not completely understood aerodynamics.
Rotorbee is offline