Don't forget to include the backfires from the P&w R2000, last time I rode one for a short field take-off and the engines ran up while under bakes, they started popping like crazy. The whole airframe shook like we had been hit by a truck, I looked up at the loadmaster and he just laughed so I figured it was fairly normal. The fleet was over 25 years old at that time and they flew them for another 10 years after that.