I was watching a video of the first A350 flight. At 0:35 one of the pilots appears to be wearing a helmet and what looks like a parachute. Is that true? Do pilots on maiden flights wear such a kit, so that in case of an emergency they can evacuate the airplane?
To the best of my knowledge, all commercial aircraft being tested have their pilots take on parachutes and hi-vis clothing in addition to creating a possible means of egress on all important flights, such as the first flight and high-speed tests.
Since getting the cabin doors open is practically difficult, the solution I think most producers use is to built a chute down the front cargo entrance which can open.
Bombardier produced a pretty extensive film for their new CSeries.
No, that's not the (main) reason.
There's something called a wing ... which has engines mounted to it !
Not a very good idea to jump out of a door if you're likely to be sucked into an engine on your way out !