 While on final approach to runway 24 in heavy rain, strong winds and poor visibility, the aircraft touched down past the threshold, and started hydroplaning.With just about of runway left, the crew tried desperately to stop, applying maximum reverse thrust and brakes, but the aircraft slid off the runway with a ground speed of approximately and plunged over a steep bank hitting a nearby bridge and crashing on the beach; splitting in two pieces and bursting into flames.Of the 164 people aboard (156 passengers and eight crew), 131 were killed (125 passengers and 6 crew), making it the deadliest airplane accident in Portugal to that point.