The possible risks of flying through unstable air resurfaced after the British man's death and the injuries suffered by scores of other passengers on a Singapore Airlines flight that hit turbulence on Tuesday. The exact cause of the 73-year-old man’s death is under investigation. Authorities said he may have suffered a heart attack, though that hasn’t been confirmed.

Based on witness accounts, the number of injuries and the airliner's sharp descent, experts point to the significant safety hazards that in-flight turbulence poses to airline passengers and crews. While turbulence-related fatalities are quite rare, injuries have piled up over the years. Some meteorologists and aviation analysts note that reports of turbulence encounters also have been increasing and point to the potential impacts that climate change may have on flying conditions.

Most incidents of planes hitting bumpy air are minor; however, airlines have made steady improvements to reduce accident rates from turbulence over time. Experts advise air travelers to stay vigilant, stressing the importance of wearing a seat belt whenever possible as a first line of protection. Turbulence is essentially unstable air that moves in a non-predictable fashion.

Most people associate it with heavy storms. But the most dangerous type is clear-air turbulence, which often occurs with no visible warning in the sky ahead. Clear-air turbulence often happens in or near high-altitude rivers of air called jet streams.

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