Perhaps the deadliest aircraft ever built, as far as the pilot was concerned, was the Messerschmitt ME 163 Komet. Projekt X or the "Devil's Sled " as it has become known, was the world's first rocket powered production aircraft. Fuel consisted of two extremely volatile propellants named c-stoff & t-stoff which when mixed together became highly explosive. It was so dangerous that during refuelling the tankers carrying the fuels were not able to come within 500 metres of each other !! Add to the equation the fact that it possessed no landing gear & you can begin to imagine why it was one of the most deadly aircraft to fly. EVER.
On October 2nd 1941 Luftwaffe test pilot Heini Dittmar became possibly the first human to approach the speed of sound. He recorded Mach 0.84, a speed of 1000.4 km/h before he experienced problems with compressibility. This was 250 km/h above the official world speed record. A ride in the Devil's Sled was surely a flight into the unknown, perhaps with no return.