By Peter Henderson and Dan Levine

SAN FRANCISCO (Reuters) - A navigation system that helps pilots make safe descents was turned off at San Francisco airport on Saturday when a South Korean airliner crashed and burned after undershooting the runway, officials said.

The system, called Glide Path, is meant to help planes land in bad weather. It was clear and sunny, with light winds, when Asiana Flight 214 from Seoul, South Korea crashed just before noon, killing two passengers and injuring more than 100.

Aircraft safety experts said Glide Path was far from essential for routine landings, and it was not unusual for airports to take such landing systems off line for maintenance or other reasons.

But pilots have grown to rely on the decades-old technology

http://ca.news.yahoo.com/airport-landing-system-off-plane-crashed-s...

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