"Darkwing" theducksmailATyahoo.com wrote in message
...
It has been a while since this happened, but my Instructor when I was
going for my PP-ASEL told me 70 was best glide in the C172 but I knew the
manual said 65, I showed him it one day and he said he was wrong and glad
I pointed it out. So if you show him info "from a higher power" he will
listen.

The problem here is that the POH for the Cessna 172 does not (as far as I
recall) discuss adjusting best glide airspeed for wind. This isn't a
question of using the wrong data for the airplane, but applying the
published data incorrectly.

There are other "higher powers" to refer to, but in this case, Nik already
tried showing the instructor one (the "Glider Flying Handbook"...an FAA
publication, I assume?), and the instructor didn't accept that as a valid
reference.

Pete