All Aero

By 1931 Alexander Lippisch had progressed to a triangular wing form which he called ‘delta’, and his Delta 1 was ready for demonstration to top German aviation ministry officials at Berlin’s Templehof airport. The test pilot, Gunther Gronhoff, performed a low level aerobatic routine (even spinning the 30 hp Bristol Cherub powered delta), they remained unconvinced. Lippisch would not get an airworthiness certificate, they declared, until he put tails on his aircraft.