In article ,
"John Carrier" writes:
After some research concerning those aircraft that were decidedly subsonic
in level flight (no pushover from altitude to gain greater speed), it would
appear mach effect is the overriding concern. The last low altitude record
before the transition to high (F-100, with several ... F-86, F-4D ...
previous to that) were all done at the Salton Sea. Hi temp (higher TAS for
mach) and low altitude (-227 MSL), delayed transonic drag rise.

Quite so - they discovered that a pushover into teh course for teh
records didn't make any difference - the drag increase was so great
that it just didn't matter. We weren't teh only ones to use this -
The Brits made a record attempt with a slightly modified Hunter over
the Dead Sea. IIRC. That would be the only Speed Record set below Sea
Level.

The PsubS bulge doesn't occur until you get into the cleraly supersonic
designs. Then it behooves a "low altitude" record to occur as high above
MSL as possible. Hence the sageburner and later Greenamyer efforts in the
high desert (less IAS, more TAS, 988 mph for Darryl ... great film by the
way).

I agree. The biggest deal there is that an afterburning turbojet
really denifits from Ram Compressionwhich gets really large above Mach
1. You get a lot more thrust, without the penalty of more Ram Drag.

Bottom line, in our running discussion, I now find your argument compelling.
I was incorrect.

I don't think that we were disagreeing on all that much, really.
Sometimes in my efforts to put things into non-technical terms, I
over-simplify. If you think I'm off, or not explaining properly,
please do jump in with a correction or an improved explanation.
Thank you for the questions, and helping me to improve my focus.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster