Big John wrote
Some (most) military birds have what is called a 'SQUAT' switch.

It's the norm for civil retracts as well, with the exception of those
few older ones where the gear is cranked up and down manually.

There was a override lever/switch next to the gear handle in cockpit
that overrode the "Squat' switch and let the Pilot retract the gear in
an emergency (like running off the end of R/W into rough ground, etc.)

Or, in a twin, engine failure and squat switch failure (in the
squatting position) at the same time. Ugly if it happens - can't
climb on one with the gear down, can't get the gear up. FWIW, I own a
twin like that - squat switch with no override. FAA won't let me
install an override (major alteration, won't field approve it, costs
tens of thousands to get an STC) but they did sign off on an indicator
that tells me what the squat switch is doing. But I digress.

There were always some 'hot rocks' that wuuld put the gear handle in
the retract postion as they started their T/O run. As they rotated and
became light on the gear (and oelo extended to activate the 'squat'
switch) the gear would retract out from under the bird giving what we
called an "Air Show" appearance on take off.

Yeah, we have them in civil aviation too.

Could the Mooney driver have been trying to show off???

Maybe. Here's the other problem. The maintenance on the gear tends
to be a lot better in the military than it is in GA - Uncle Sam is
paying for everything, and it's done by the book. Not too long ago a
flight school that shall remain nameless had an incident. Prop strike
on takeoff. Everyone claims the pilot prematurely retracted the gear.
Maybe so - but the one thing I know for certain is this - I looked
very carefully in the wheel wells of that airplane just a few months
ago, when they had problems getting a green light on the gear. The
squat and limit switches were a bad joke - some of them were held in
place with little more than good intentions. Pilot error or lousy
maintenance? Don't know.

I do know that several weeks later, they had a nose gear collapse on
another retract. Pilot saw the nose dropping on landing and went
around (and got the prop tips - dumb move, lucky they stayed in
place). I saw his second approach and landing. It was perfect -
soft, on the mains, nosegear held off as long as possible. The mains
were solidly down and locked, but the nosegear collapsed. The
mechanic now claims there's no problem with the gear.

I do know that the last time I let someone besides myself (a certified
mechanic, and a supposed expert on my plane no less) work on my gear,
I had a strut collapse on landing just a few flights later. He did a
hell of a job trying to convince me that it was a hard landing, and
almost had me believing it - but then I got to work, and saw that the
snap ring was flopping around loose around the strut - with no damage
to the groove or the snap ring. All became clear when I replaced the
seals and started to reassemble - the snap ring would look like it was
seated, and would seem to hold, but in fact was not in the groove.
Unless you knew what you were looking for or were suspicious, there
was no reason to believe it wasn't seated. I pushed it further,
seated it, and haven't had a problem since.

I have quite a few friends who have had gear problems, and my
experience is that it was more often mechanical screwup (up to and
including failure to replace a 20+ year old high pressure hydraulic
hose at annual after being specifically instructed to do so by the
owner) than pilot error.

Michael