An ATR 72-212 was operating a domesting flight between Mayagüez and San Juan, Puerto Rico. Onboard a crew of 4 and 22 passengers. The captain was the pilot monitoring (pm) and the co-pilot was the pilot flying (pf). After all preparations were complete the aircraft took off from Mayagüez at 14.15 local time (lt)
The aircraft in its final position (Source www.baaa-acro.com © NTSB)
The aircraft was approaching San Juan just over 20 minutes later, the crew obtained the latest weather and noted the wind as 060º at 17 knots, gusting at 23 knots. The final approach speed was determined to be 95 knots. At 14.34 ATC warned the crew of possible wake turbulence of a preceding Boeing. The captain instructed the pf to reduce the speed to 140 knots.
Close up of the aircraft in its final position (source www.baaa-acro.com ©Julio Ortiz)
At 14.46 the tower controller cleared the aircraft to land, and the pf put the aircraft in a left turn towards the runway and transferred to the VASI (Virtual Approach Slope Indicator) for vertical guidance. The captain advised the pf to keep to nose down or get some power-up. This resulted in a GPWS (Ground Proximity Warning System) "GLIDESLOPE" alert.
The aircraft in its final position (source www.baaa-acro.com © unknown) A little later the aircraft crossed the threshold of runway 08 at an altitude of 45 feet and at a speed of 110 knots indicated airspeed. After crossing the threshold the captain advised the pf "power in a little bit, don't pull the nose up, don't pull the nose up". A short while later the first of a series of touchdowns occurred;
1st Touchdown ~1600 feet passed the threshold of runway 08. At touchdown, the captain called for more power, followed a second later by the statement "My aircraft". The aircraft bounced back into the air reaching an altitude of approximately 4 feet.
2nd Touchdown ~2200 feet passed the threshold of runway 08. The aircraft bounced back into the air pitched up to an angle of +9º and reached an altitude of 37 feet. The pitch angle decreased to -3º initially, decreasing to -10º
3rd Touchdown ~3300 feet passed the threshold of runway 08. Vertical and lateral loads of about 5 Gs and 0.85 G were recorded on this touchdown. Causing the aircraft to bounce 24 feet back into the air
4th Touchdown ~4000 feet passed the threshold of runway 08. This touchdown was at a negative pitch attitude (-7º) and left-wing down (-29º from wings level)
The aircraft left the paved area of the runway and came to a complete stop ~217 feet left of the runway centerline and ~4317 feet beyond the threshold of runway 08. All of the occupants evacuated the aircraft without injury.
The NTSB (National Transportation Safety Board) investigated the accident and published its report on the 7th of September 2005. (Click here for access to the report). Besides several safety recommendations the NTSB identified the following probable cause for the accident;
"The captain’s failure to execute proper techniques to recover from the bounced landings and his subsequent failure to execute a go-around."
Ground track of the aircraft (top diagram) and altitude profile of the aircraft's landing. (Source and © NTSB)