Jay Honeck wrote:
This is why you leave everything really loose - like, each screw only
engaged a couple of turns - until you've got all the screws in.

That's what REALLY ****ed me off -- I did that! I thought I was so
damned smart, just finger-tightening each screw before torquing them
all down -- and that last screw STILL kicked my butt.

Maybe the screws involved are much shorter than I'm picturing in my
head, but it seems like there ought to be lots of turns between "only a
couple of threads engaged" and "finger tight". If they're countersink
head, finger tight means the countersink on the screw is already
touching the countersink on the panel and constraining the movement of
the panel somewhat. If the screws are long enough, you should be able
to thread them in such that the clearance hole in the panel is still
floating around the shank of the screw.

I did get a little experience in this direction when I helped R&R a
cowl on a 172. The screws on that were countersink head Phillips and
about an inch long overall. I don't know if that's how long they were
supposed to be, but it was pretty easy to get things lined up when
reinstalling. I could engage the screw a couple of turns and go on
to the next one, and still have a little "wiggle room" to get things
to line up. Once I had all the screws started, the owner put the
electric screwdriver on them (carefully) to drive them all the way home.

Matt Roberds