Ernest Christley wrote:

A flag on the part of the protagonist moves the responsibility from the
antagonist seeing to the protagonist being seen (any time you move your
vehicle, you're the antagonist, the mover, the doer, the responsible
party). If the Avenger's co-pilot couldn't ride or walk a wing to the
run-up area, stick a bug-eye mirror on a stick or out on a wing
(temporarily). The solutions are simple, abundant, and in use all
around us every day.

With the price and availability of tiny little video cameras and LCD
displays, I can't imagine why anyone who could afford to fly a warbird
couldn't afford to put a forward-looking video system in place (even
if it's only a temporary installtion used for crowded events). It
would cost what - $100? - to prevent blind taxiing.

Mark Hickey