Accident Details
The pilot and owner of a Cessna 525A initiated a visual flight rules (VFR) approach and landing to a runway 3,009 feet in length. A tailwind of about 7 knots was present. The aircraft touched down 642 feet past the approach end of the runway. The reference landing speed (Vref) was calculated to be 108 knots; however, data from the Enhanced Ground Proximity Warning System (EGPWS) indicated that the ground speed was approximately 137 knots 9 seconds before touchdown, and at touchdown the speed was estimated to be about 130 knots.
Pilot Actions After Touchdown
Following touchdown, the pilot selected ground flaps, which moved the flaps from 35 degrees to 60 degrees. The spoilers auto-deployed, and the speed brakes were extended. The pilot reported that after applying the brakes, he felt the brake pedals pulsing and did not believe the airplane was slowing. He released the brakes for a few seconds and then reapplied them. Again, he felt pulsing in the pedals but the airplane was not slowing as expected. He released the brakes, reset the flaps to takeoff, and applied power to abort the landing when he was approximately halfway down the runway.
Runway Overrun
The airplane departed the end of the runway and traveled about 300 feet beyond. Skid marks indicated that the initial touchdown was most likely made with brakes applied and no locked wheel crossover protection. Additional skid marks revealed that the airplane became airborne after touchdown and, over the next 750 feet, touched down three more times. Each subsequent touchdown occurred without the full weight of the airplane on the wheels. Tire marks on the last half of the runway were consistent with brakes applied and anti-skid operative.
Landing Performance Considerations
Using the approved flight manual standards, the airplane would have required 3,155 feet to stop, based on crossing the threshold at 50 feet at Vref, including a ground roll of 1,895 feet. The pilot touched down at 642 feet from the threshold, which left sufficient runway for stopping. Given the pilot's touchdown point, the airplane was capable of stopping on the runway with a Vref as high as 120 knots.
Approach Characteristics
The approach was unstabilized, with four aural warnings, including two sink rate warnings on final approach. The last sink rate warning occurred with a descent rate of over 1,700 feet per minute, 19 seconds prior to touchdown, and about 400 feet above the ground. The last airborne GPS position was about 2,000 feet from the runway touchdown point, which would have required a flight path angle of about 3.8 degrees to achieve the reported touchdown position.