Testing your glide. Are people doing this?

In rec.aviation.owning Robert Moore wrote:
: NOT TRUE!! A B-747 has about the same glide ratio as the B-707s
: that I flew for 17 years, 20:1 or better. From 35-37,000'(6nm),
: we could do 125nm easily.

I thought I heard somewhere that one of the reasons the "glide
ratio" on the bigguns is so high is that it's tested with the turbine's
power pulled all the way back. The engines, however, have a great deal of
idle thrust, which aids in the glide ratio.

I don't know this for sure, but I've heard it's partially true.
Any thoughts?

-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************