The Federal Aviation Administration attempted to reduce the incidence of CFIT by mandating in 1974 that aircraft operate with Ground Proximity Warning Systems (GPWS). But the systems had limitations.

The TSB said the aircraft's ground proximity warning system issued an alert 2.6 seconds before landing, with the plane descending at a high rate and traveling at 136 knots (approximately 155 mph).

There were up to 190 passengers and crew onboard flight EZY2251 when a siren alert sounded in the cockpit after the Ground Proximity Warning System was triggered, the Sun reported. The pilot ...

The TSB of Canada report says that when the plane’s ground proximity warning system sounded 2.6 seconds before touchdown, the airspeed was 136 knots, or approximately 250 kph (155 mph).