From Barry Schiff:
I rechecked rudder trim: 6 degrees right. The canopy was locked, engine-coolant temperature was in the green, boost pump was on, and the mighty Merlin was feeding from the left tank.
Toe brakes firmly applied, I advanced the throttle to 2,300 rpm and 30 inches of manifold pressure. The Mustang trembled slightly as if champing at the bit, impatient to be cut loose.
Brakes released, we began to accelerate, and I kept my feet dancing to arrest directional transgressions. As airflow increased across the rudder, I advanced the throttle to 3,000 rpm and 40 inches. (The geared propeller turns at only 1,437 rpm.) I held the stick fully aft to keep the tailwheel on the ground and assist with tracking. I had been taught that the best way to maintain directional control is to increase power in steps as control effectiveness increases.
At 50 knots I slowly but forcefully pushed the stick forward. The end of the runway came into view, and I increased power to 55 inches (120 gallons per hour of fuel flow). I began to appreciate why the British (for whom the P-51 was developed) called this airplane a Mustang, a wild stallion of the American prairie. The unbridled acceleration, energy, and noise level are startling and impressive.
Although 61 inches of manifold pressure are available for takeoff, I was not ready for the combination of twisting and turning forces that accompany 1,490 horsepower slinging that huge propeller. (Torque alone is impressive and causes the left tire to wear much faster than the right.) A takeoff using maximum power could wait until I had more experience.
Besides, a lightly loaded Mustang inspired by 55 inches of manifold pressure performs better than a wartime edition loaded with armament and drop tanks using 61 inches. During emergencies, combat pilots could pull 67 inches (1,720 horsepower), and modified Mustangs racing at Reno develop as much as 155 inches.
I raised the nose at 100 knots and the Mustang was airborne immediately unlike any other piston-powered single I had ever flown. With landing gear retracted, the climb at takeoff power is exhilarating, almost 4,000 fpm.
I was relieved to discover that it takes less right-rudder pressure during initial climb than a Cessna 210. The immediate goal, though, was to accelerate to the best glide speed of 150 knots, just in case.
Fly it like this (don't forget the rudder trim) and she's a dream.