Douglas DC-6 with R-2800 engines

This is the first Aircraft I flew on for American Airlines the Douglas DC-6. The Pratt & Whitley R2800 engine was a great powerplant. Just try to start the engine without backfiring.
Trail the cowl flaps -- we are about to take off.
On my very first Take Off I forgot to unlock the flight controls and we had to abort. The next 5000 T/O's I thought of that FIRST TAKE OFF.