What happened
On July 16, 2007, an ATR-42-300, registration PT-MFK, operated by Pantanal Linhas Aéreas, was performing a flight from Araçatuba to Bauru-Arealva. Due to adverse weather conditions at the destination, the crew diverted to Congonhas Airport (SBSP) in São Paulo. Before landing, the crew was notified that the runway was being temporarily closed for water depth assessment, but they were cleared for approach with instructions to report braking action after touchdown.
At 12:42 PM, the aircraft landed on runway 17R during light rain. Immediately upon the nose gear making contact, the aircraft began to slide to the left. As the aircraft exited the paved surface, the left landing gear and tires struck a concrete box, causing severe damage. Approximately 100 meters further, the right landing gear tire was torn by a light signal support. The aircraft continued across taxiway C and through the grass before coming to a stop near runway 17L/35R. All 25 occupants (21 passengers and 4 crew members) were uninjured, though the aircraft sustained heavy structural and hydraulic damage.
The investigation
CENIPA's investigation focused on the runway conditions and the crew's response to the loss of control. Investigators found that while the friction coefficient was above the minimum required limit, the runway's macrotexture was below the minimum standard. Crucially, the runway lacked grooving, which is essential for accelerating water drainage. The investigation also noted that the airport lacked a Runway End Safety Area (RESA) and an Engineered Materials Arresting System (EMAS), increasing the risk of catastrophic outcomes during long landings or excursions.
Findings
- Adverse weather conditions: Light rain caused water to accumulate on the runway surface, leading to hydroplaning.
- Infrastructure deficiencies: The lack of runway grooving prevented effective water drainage, facilitating the hydroplaning event.
- Improper control input: The pilot applied full right rudder pedal during the hydroplaning event, which generated a force that aggravated the leftward excursion.
- Training gaps: The investigation suggested that pilot instruction likely did not adequately cover the correct rudder application techniques to use during a hydroplaning event.
- Lack of safety margins: The absence of a RESA at Congonhas Airport increased the severity of the excursion.