Flight of two, IFR

Andrew Gideon wrote in
online.com:

How does that work? Is visual contact required, or can
this be done electronically?

Visual. It's rare for the visibility to be so low as to be
unable to see past the wingtip. And military formation flights
are very close together. Helicopter formations have to be a
little further apart, but I've flown in formation IFR in UH1s.
It's not really that difficult in most cases, at least no more
difficult than flying a tight formation in the first place. We
also used to fly night formations without lights, using only the
cockpit instrument lights of the ship we were flying on, with
10+ ship formations, landing to completely unlit LZs with one
strobe to mark the landing site for the lead. Not fun, not
smart, but we were young and stupid and drawing flight pay. The
ones I felt sorry for were the grunts in the back.

--
Regards,

Stan