The Martin T4M made replacement easy to postpone

The Martin T4M anchored American carrier strike aviation for about a decade and remained the Navy's principal carrier strike aircraft while several technology generations passed. Its 363-mile range, 85-knot cruising speed, 99-knot maximum speed, under-fuselage bomb or torpedo load, and single rear machine gun were respectable for a 1928 torpedo bomber. The T4M compared well with contemporaries such as the Blackburn Ripon and Mitsubishi B2M, and crews built reliable doctrine and experience around it. Proposed successors in the early 1930s offered too little improvement to justify new training, maintenance, and logistics costs. That economical decision preserved a useful aircraft but allowed replacement skills and designs to stagnate. When Brewster, Vought, Northrop, Douglas, Great Lakes, and Grumman entered the eventual competition, the wide field could not instantly replace experience lost across skipped cycles. The TBD won partly on reliability, but its otherwise unremarkable character showed how competition alone could not erase that accumulated development gap. By the mid-1930s the surviving T4Ms were physically wearing out, leaving the Navy compelled to choose the best current proposal rather than move through a gradual sequence of improvements.