On Monday, March 4, 2019 at 12:50:38 PM UTC-5, ProfJ wrote:

I've done some professional work on measuring pilot responses in air accidents - including looking at cockpit and control systems data for fatal accidents where the instructor took control shortly before the crash. I am certain that the average CFI's delay in switching from close observation to action (taking control) is going to put them way behind the response of a trainee who is at solo level and actively flying the glider. It takes much longer than you might expect to make that cognitive switch (this is the same reason why semi-autonomous cars are going to keep crashing). This also gels with my one and only experience of kiting a towplane, when I was a trainee. I had pulled the release before the instructor recognized there was a problem. This was compounded by the fact that from the back seat, with the glider and towplane bouncing up and down in strong thermals, he was used to the towplane being out of sight and could not judge its attitude. But yeah, the CFI has to carry the can no matter what. I have massive respect for the calm demeanor they bring to the job :-).

- Having the tow plane out of sight is totally unacceptable. In some gliders (a common low-performance training glider in the USA comes to mind :-) it can be hard to see the towplane (or the instruments) from the back seat over the shoulders of a tall student, but we use pillows or whatever it takes.

- I forget who was it that wrote that an instructional flight has green, yellow and red zones. One can let the student make gross errors in the green zone (at altitude). Need to maintain a safe path to a landing in the yellow zone (pattern). In the red zone (takeoff and landing) the instructor must be ready for instant takeover of the controls. One of the very few times when, as an instructor, I've grabbed the controls by force (before even saying anything), was when a student started climbing too high after liftoff.. Of course I explained it all to the student later.

- Moshe (trying to maintain that calm demeanor)