Drop tank

[1] The drop tank was later used during the Spanish Civil War to allow fighter aircraft to carry additional fuel for long-range escort flights without requiring a dramatically larger, heavier, less maneuverable fuselage.

Mitsubishi A5M, designed by Jiro Horikoshi, began carrying an external underside drop tank to provide fuel for extended range in 1937 and during World War II, the Luftwaffe began using external fuel tanks with the introduction of a 300-litre (66 imp gal; 79 US gal) light alloy model for the Ju 87R, a long-range version of the Stuka dive bomber, in early 1940.

The first drop tanks were designed to be discarded when empty or in the event of combat or emergency to reduce drag, weight, and to increase maneuverability.

They insisted formations of heavy bombers with multiple machine-gun positions would be self-defending, and that long-range escort fighters would be unnecessary, or even impossible to design.

[3][4] In the face of such entrenched attitudes in 1941 airmen such as Benjamin S. Kelsey and Oliver P. Echols worked quietly to get drop tank technology added to American fighters, beginning with the Lockheed P-38 Lightning.

It was only with drop tanks supplying 1,700 litres (450 US gal) of extra fuel per fighter that P-38s could carry out Operation Vengeance, the downing of Admiral Isoroku Yamamoto's aircraft.

[7] External drop tanks turned the Thunderbolt from a short-range interceptor aircraft into a long-range escort and air superiority fighter, enabling it to accompany bombers from the British Isles into Germany and made it possible for heavy bomber formations to undertake daylight raids under escort by North American P-51 Mustangs.

[8] Faced by wartime metal shortages and a need to extend the range of fighter craft, the British came up with drop tanks made of glue-impregnated kraft paper, which had excellent tolerance characteristics for extreme heat and cold necessary for operation on an aircraft as well as being waterproof.

Before final assembly wooden anti-slosh baffles were installed, pipes and fittings were attached and the interiors coated with fuel-resistant lacquer and the three pieces were bonded together in press.

The Convair B-58 Hustler, the first operational bomber capable of Mach 2 flight, had no bomb bay: it carried a single nuclear weapon plus fuel in a combination bomb/fuel pod underneath the fuselage.

After World War II, hot rodders raced the dry lakes of California to set new land speed records.