Thanks for the explanation of the "flick roll", Kirk. I hadn't
considered roll/yaw coupling because of the straight wings of the tugs.
Wouldn't a bent wing jet make a heck of a tug?

And did nobody catch my error about Australian towing? They go to LOW
to shortly after takeoff. I verified this with a Crown subject who
resides in the USA and has flown in Oz.

On 4/30/2015 10:50 AM, kirk.stant wrote:
On Thursday, April 30, 2015 at 10:22:16 AM UTC-5, Dan Marotta wrote:
If I understand the difference in idiom, the British term "flick
roll" is equivalent to the US term "snap roll". If that's correct,
stalling the vertical fin will not cause a snap roll which is a spin
in the horizontal plane. And, as we all know, a spin requires a
stall with yaw. In the case of a snap roll, it is an accelerated
stall and I don't see any change in AoA of the wing to cause that
stall. But then I'm just a poor victim if US military flight
training... Or I could be wrong on the term "flick roll". Or the
BGA manual could be (horrors) wrong!
Dan, I remember reading the BGA article and I think they were referring to what the towplane did when the vertical stabilizer stalled (due to the yaw from a glider WAY out to the side). The sudden loss of all yaw stability results in the tug suddenly yawing away from the glider, and the roll due to the sudden yaw results in a pretty impressive roll. Perhaps not a classic "snap roll" but interesting nevertheless!

So many interesting things going on in this thread! For the original poster: Bob, it sounds like you have a tow pilot who needs some "counseling" on his responsibility as a tuggie. If it's a commercial operation, talk to the chief towpilot or the owner, and worse case take you business somewhere else. In a club situation, that tow pilot should be retrained, and if he continues to ignore the standards, asked to leave (it doesn't sound like he's a glider pilot).

For Dave Springford and Don Johnstone (assuming you fly in Britain), are you saying that steering turns are not done there? What if the towplane is taking you downwind over unlandable terrain, and your radio doesn't work? You would just sit there? As far as steering turns being dangerous - how so? Unless you are deliberately holding off the yaw due to the glider moving off to the side (as in boxing the wake, which should be prebriefed prior to the launch), a smart tow pilot will just let the glider gently pull him in the direction he wants to go. And you have to move out pretty far before you significantly change the flightpath of the towplane. So, a competent glider pilot will stay behind the towplane, a competent tuggie will be clearing the flight path, and working as a team, they will proceed the the optimum release point, using whatever works best (radio or signals). Where a radio is really nice is the rare situation where the glider is trying to force the tug to go somewhere he really doesn't want (like a cloud, or other traffic). Without a radio, you pretty much are stuck with standing on the rudder and the glider should realize that you are intentionally refusing to turn. But the glider should never go so far out to the side that he risks stalling the tug tail (which is really far out!). So, nothing crazy at all about it.

By the way - the military uses visual signals all the time in high speed jets, despite all sorts of fancy radios. Why talk when you can do it silently...

Finally, Dan, I know that guy! He's the glider pilot who gets pulled through a boomer multiple times, underneath a climbing gaggle, and refuses to get off until 3000'agl, which is of course when you are in the sink from that boomer! Those glider guys, they are such a hoot!

Kirk
66
(Flies on both ends of the string)

--
Dan Marotta