Lippisch Delta 1

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 re-mained unconvinced. Lippisch would not get an airworthiness certificate, they declared, until he put tails on his aircraft.