...or he might be referring to the exhaust extension on the Bell Medium twin (the part that the engine exhaust ejects into, which carries the exhaust gases to the exhaust deflectors). I think these connect to the airframe in 3 places and the mounts are known to crack, and they can be cracked for a long time before being detected. They usually get sent away for specialist welding repair. If it were detected in the field I wouldn't have an issue flying the helicopter back to a repair facility (if requested by maintenance), and once there ground the helicopter for repair.
I've also seen the sheet metal cracked in the place described by the OP, and from what I remember the crack was found to have been previously "drill stopped", however during susequent service the crack had migrated past the repair. So in this instance the decision had been made to keep flying, with the intention to change it at the next opportunity.
Last edited by gulliBell; 21st January 2013 at 20:53.