#1 S-76C, 12 degrees C, 11200 lbs, 11 souls, 20 knots wind - massive explosion (well it seemed like it at the time - hot end failure) at CDP on a platform take off. Deck 100 ft AMSL, copilot says he saw 5 feet on the radalt above water as we accelerated away. Nr drooped to 91% with N1 pegged at 102.7 before milking it back up. Cabin filled with smoke and that hot, hot metal smell. Turned out to be an easy exercise in retrospect but certainly not at the time. Put the success down to simulator partly, but mainly to our C & T people who as part of base checks pull one at 100 foot hover and have you fly away/land on runway however it plays out (throttle of "good" engine previously set so that you are just light on wheels with that engine - some will argue its hanging yourself out there with such a practice but none of our pilots have mentioned any qualms and is the best of training if you want to risk it)
#2 Stinking hot day (about 35C I think) 76C and 50 or so pounds short of gross for the conditions. In hover trimming engines prior to take off when a soft "pop" was heard and aircraft settled gracefully to the runway with the ITT of failed engine at 1000C - hot end again and same aircraft as before but other engine and no, this engine was not installed at time of previous failure. No cabin smoke this time