Why did yuri gagarin die?

By 1968 Gagarin was a colonel, deputy head of cosmonaut training and a national monument the state was reluctant to risk. He had been kept out of cockpits for long stretches and was working his way back to full flight status. On the morning of 27 March 1968 he took off from Chkalovsky airfield near Moscow in a MiG-15UTI two-seat trainer, with the experienced test pilot Vladimir Seryogin in the other seat. Minutes into the exercise Gagarin reported the task complete and asked to return to base. There were no further transmissions. The aircraft struck the ground steeply in woodland near Novosyolovo, in the Vladimir region, and both men were killed.

The investigating commission decided that the crew had made an abrupt manoeuvre, to avoid another aircraft, a weather balloon or the base of a cloud layer, and that the trainer entered a spin from which there was not enough altitude to recover. The findings were not published at the time, which guaranteed decades of speculation, some of it lurid: sabotage, alcohol, even a secret survival.

What emerged later was less dramatic and more damning of the system around the flight. The weather briefing was out of date and the cloud base far lower than the crew had been told, the training zone was not clear of other traffic, and the spin-recovery procedure for the type demanded height the pair no longer had. Alexei Leonov argued for years that an unauthorised supersonic fighter had passed close enough for its wake to upset the MiG, a version he said the original data supported. No single account has satisfied everyone, but the mechanism has never been seriously disputed: a spin entered too low to break out of.