An incredibly stupid airplane accident. His machine's landing gear light didn't go on (these lights indicate that the wheels are down -- kinda big part of your landing checklist). A helicopter pilot nearby offered to fly up close to the plane and check. Heinz's charter pilots okayed it. He flew too close... everyone on both planes, and some people on the ground (3?) lost their lives.
None of the pilots (there were two on each craft) had had any formation flying training. It's something that looks easy when military or airshow pros do it, but really needs special training to do. To put it in terms that make sense to the 98% of you who don't fly, it's kinda like the way we can all drive a pickup truck, but would have a heck of a time backing up an 18 wheeler like a pro driver.
The investigation, by the way, showed that the landing gear were fine, it was the light that was bad, AND on that type plane you can't tell if they are in a safe condition by looking at them from another plane, anyway, even if you are the mechanic who works on that landing gear!
d.o.l.
Criminal Number 18F
Amazingly tragic!