The Embraer Phenom 300 that overran the runway at Blackbushe Airport in southern England on July 31 received multiple pull up warnings from its terrain awareness warning system (Taws) before touching down far beyond the threshold of the 3,474-foot runway with 1,437 feet of pavement remaining, according to the UK’s Air Accidents Investigation Branch (AAIB) preliminary report, published on August 6. The accident destroyed the Saudi Arabian-registered jet (HZ-IBN), inbound from Milan, Italy, and claimed the lives of all four people on board–the 57-year-old 11,000-hour pilot and three passengers, which included members of Osama Bin Laden’s extended family. The weather was good VFR, with visibility better than six miles, light wind and no low clouds.
Towards the end of a visual downwind to Runway 25, the Phenom overtook a microlight and climbed slightly to pass ahead of and above the smaller aircraft. As this climb began, at approximately 1,000 ft above aerodrome level (aal), the Tcas issued a descend resolution advisory (RA).
The Tcas RA changed to maintain vertical speed and then adjust vertical speed, but the AAIB suggests these instructions might have been to resolve a second conflict with another aircraft above the Phenom, to the east of the field. Following this climb, the Phenom then descended at up to 3,000 feet per minute toward the threshold of Runway 25. The Tcas annunciated clear of conflict when the jet was 1.1 nm from the runway threshold, at 1,200 ft aal and flying at 146 knots with the landing gear down and flaps 3 selected. Between 1,200 and 500 ft aal the rate of descent averaged approximately 3,000 fpm, and six Taws pull up warnings were triggered on final by a 2,500-fpm descent rate at 500 feet agl.
The aircraft operator estimates that the landing weight was 14,378 pounds/6,522 kg. Embraer told the AAIB that at this weight the target threshold speed would have been 108 knots–42 knots less than the 150 KIAS the aircraft was doing when it crossed the threshold of Runway 25 at 50 feet.
Tire marks show that the jet touched down 2,329 feet past the threshold with 1,437 feet of pavement remaining, and the FDR revealed that the touchdown groundspeed was 135 knots (134 KIAS). Embraer told the AAIB the Phenom would have required 2,021 feet to come to a halt from this speed, noting that its calculation was based on a maximum-performance landing as demonstrated by test pilots during certification trials.
The aircraft overran the paved runway surface, 10 feet left of centerline, before striking a three-foot-high berm and briefly becoming airborne again. It then collided with several cars parked at an adjacent business. The wings detached and the aircraft exploded.
The pilot, with 1,180 hours in type, had logged 23 hours in the preceding 90 days and five hours in the preceding 28 days.