 As a result, maneuvers were restricted until the tank was down to about and the external tanks had been dropped.Problems with high-speed "porpoising" of the P-51Bs and P-51Cs with the fuselage tanks would lead to the replacement of the fabric-covered elevators with metal-covered surfaces and a reduction of the tailplane incidence.With the fuselage and wing tanks, plus two drop tanks, the combat radius was .