wrote:
The band of energy you need to be in to complete a safe pattern
insertion from 50 feet agl is pretty wide, from 100 knots up to
redline. If you find yourself unable to measure this until you are
already within the airport boundaries, you need to work on this skill.
Clearly, we are discussing this because there are pilots attending
races who cannot do this.

You're right, some of us who attend races cannot, or will not, do this.
I haven't made a pass under 300 feet in at least 10 years. Part of it
is the fact that, as with many, this "skill" was of necessity
self-taught (the closest I've ever come to being killed in a low pass
was when a CFIG was flying from the back seat). Part of it is the fact
that the vast majority of my glider flying is now at airports where
there is a mix of traffic, and low passes are simply not appropriate.
When I honestly looked at my past history of low passes, the number of
minor "incidents" (near encounters with other aircraft that I had not
previously been aware of, ending up with a less than expected amount of
energy, not remembering an important checklist item, etc.) ended up
being just too large a percentage of the overall total. So, I came to
the conclusion that I should no longer work on this particular skill...

Marc