David Doyle. 9" x 9". The Grumman-designed TBF Avenger was unquestionably the most successful torpedo bomber in the US fleet during WWII. Developed just prior to the US entry in WWII, the type made its combat debut at the Battle of Midway. Demand for the large carrier-borne aircraft, which could drop conventional bombs and depth charges in addition to torpedoes, soon outstripped Grumman's capacity.