On a helicopter having a main fuel tank and outer curved walls with connector lugs thereon, an auxiliary fuel tank for each side of the helicopter, each tank being of aerodynamically streamlined configuration having an outer convex wall, a top rounded wall, a bottom rounded wall and an inner concave...http://www.google.com/patents/US4860972?utm_source=gb-gplus-sharePatent US4860972 - Auxiliary fuel tanks for aircraft
