In November of 1979, I took off as a passenger in a 727 from an airport at 6200 ft above sea level, to climb steeply over the 13,000 foot pass. We immediately went into a hail storm, and it sounded like we were inside a snare drum.
All three engines were knocked out, and we glided through the clouds, in quiet panic. After a couple of minutes of gliding (as much as a 727 can), one engine caught, then another, and finally the third. The pilot put it into an upward spiral in the space he thought he had between the mountains until he got over the clouds and mountain.
They diverted the flight to the closest airport and we deplaned (9000 ft above sea level). There was no longer any paint on the plane. Just clean aluminum. They brought some mechanics from their hub, looked over the plane, and we got back on board to continue our flight.