Complex sentence: Chuck Yeager was nearly killed in December 1963 when he lost control of an NF-104A during a high-altitude record-breaking attempt; he lost the tips of two fingers and was hospitalized for a long period with severe burns after ejecting from the aircraft.
Split into simpler sentences: Chuck Yeager was nearly killed, in December 1963, when he lost control of an NF-104A during a high-altitude record-breaking attempt. He lost the tips of two fingers and was hospitalized for a long period with severe burns after ejecting from the aircraft.