Final Report: No cause determined for hydraulic leak

 - December 1, 2008, 9:06 AM

Cessna 750 Citation X, New York, N.Y., April 3, 2008–The Citation X ran off the runway on landing at John F. Kennedy International Airport because of the copilot’s failure to maintain directional control during the landing roll. A contributing factor was a loss of system A hydraulic fluid for undetermined reasons and the flight crew’s failure to follow the checklist sequence.

The WM Aviation Citation was on approach when an EICAS warning illuminated, indicating the hydraulic fluid level on system A was low. The pilot and copilot completed the checklist procedures down to the blow-down of the landing gear but did not follow the checklist sequence. They failed to evaluate the hydraulic pump to see if the pressure could be restored. The flight crew turned on the A side pump, engaged the power transfer unit and lowered the landing gear.

When the airplane touched down, the brakes did not work, but the emergency brakes appeared to work. The copilot applied reverse thrust and the airplane started veering to the right, resulting in a loss of directional control. The airplane went off the right side of the runway and sheared off the left main landing gear before stopping. Download of the EICAS system revealed the copilot had not taken the right thrust reverser out of reverse thrust.