To supplement The Custodian's writeup above, it is not true that the P-47 had poor climb performance overall. Early models of the Jug were equipped with a 12 foot, four bladed propellor. Though large for the time, it proved too small to take full advantage of the R-2800's power. Beginning with the P-47D-22RE and P-47D-23RA the early propellor was replaced with a very large (13 feet in diameter) propellor. The new prop was so wide it was referred to as the "paddle blade" propellor. (either a Hamilton Standard Hydromatic 24E50-65 or a Curtiss Electric C542S). The new propellor made take-off and landing more interesting, as it only permitted one foot of ground clearance, but it gave an enormous boost to the Thunderbolt, particularly in rate of climb. Retrofit kits were made available and added to earlier P-47's because the change proved so effective.

In the book Thunderbolt! by Thunderbolt ace Robert S. Johnson and aviation author Martin Caiden Johnson describes how dramatic the effect was. In mock dogfights wit the British Supermarine Spitfire the older Thunderbolts had been readily outclimbed, with the paddle blade the situation was immediately reversed, with the Thunderbolt easilty outclimbing the Spitfire 9. Johnson himself stated: ". . . . never again did a Focke Wulf outclimb me."

Caiden later quoted the story from Thunderbolt in his book Fork Tailed Devil: The Story of the P-38 in order to demonstrate enormous possible impact of a single design change. The paddle blade propellor made the Jug into a climber, and it was not surpassed by any German aircraft until the ME-262 jet fighter, which was in another league entirely.