The strategic bombing proponents within the USAAF, called the Bomber Mafia by their ideological opponents, had established in the early 1930s a policy against research to create long-range fighters, which they thought would not be practical; this kind of research was not to compete for bomber resources. Aircraft manufacturers understood that they would not be rewarded if they installed subsystems on their fighters to enable them to carry drop tanks to provide more fuel for extended range. Lieutenant Kelsey, acting against this policy, risked his career in late 1941 when he convinced Lockheed to incorporate such subsystems in the P-38E model, without putting his request in writing. It is possible that Kelsey was responding to Colonel George William Goddard's observation that the US sorely needed a high-speed, long-range photo reconnaissance plane. Along with a change order specifying some P-38Es be produced without guns but with photo reconnaissance cameras, to be designated the F-4-1-LO, Lockheed began working out the problems of drop tank design and incorporation. After the attack on Pearl Harbor, eventually about 100 P-38Es were sent to a modification center near Dallas, Texas, or to the new Lockheed assembly plant B-6 (today the Burbank Airport), to be fitted with four K-17 aerial photography cameras. All of these aircraft were also modified to be able to carry drop tanks. P-38Fs were modified as well. Every Lightning from the P-38G onward was capable of being fitted with drop tanks straight off the assembly line.