Problem is on the new airbuses, the parking brake selector holds the brakes at a lower pressure than standings on the pegs themselves - so all engine runs have to be carried out with a bloke on the brakes.

Quiet what happened will be revealed soon, whether it was a BSCU or brake pack failure, or simply (and more probably - human error).

I think it will change the attitudes of a few people regarding strapping in during engine runs, I must admit during all the runs I've been involved in (737 and A320) we have never bothered

Also, the aircraft are never chocked when we do them....on the brakes only.

Hope the guys make a full recovery soon