HZ-IBN on approach to Runway 25 shortly before the accident (photograph taken by Geoff Pierce) Preliminary investigation by UK Air Acc...
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| HZ-IBN on approach to Runway 25 shortly before the accident (photograph taken by Geoff Pierce) |
Preliminary investigation by UK Air Accidents Investigation Branch (AAIB), indicates that the Phenom 300 business jet involved in the July 31 fatal accident at Blackbushe Airport, Hampshire continued a speedy and unstable approach with high descent rate, despite a series of warnings from the onboard traffic collision avoidance system (TCAS).
The aircraft landed short of runway and hit a earth bank, briefly became airborne and collided with several parked cars, before coming to rest.
The aircraft registered HZ-IBN, entered the left-hand circuit for Runway 25 via the crosswind leg. Towards the end of the downwind leg, it overtook a microlight aircraft, before climbing slightly to pass ahead of and above that aircraft.
As this climb began, at approximately 1,000 ft above aerodrome level (aal), a TCAS ‘descend’ Resolution Advisory (RA) was presented to the pilot of HZ-IBN, to resolve a confliction with the microlight. The TCAS RA changed to ‘maintain vertical speed’ and then ‘adjust vertical speed’, but these instructions may have been to resolve a second confliction with another aircraft which was above HZ‑IBN, to the east of the aerodrome.
Following this climb, HZ-IBN then descended at up to 3,000 feet per minute towards the threshold of Runway 25. The aircraft’s TCAS annunciated ‘clear of conflict’ when HZ-IBN was 1.1 nm from the runway threshold, at 1,200 ft aal at a speed of 146 KIAS, with the landing gear down and flap 3 selected.
The operator estimated that the landing weight was 6,522 kg. The aircraft manufacturer Embraer, calculated that at this weight the target threshold speed was 108 KIAS.
The aircraft continued its approach at approximately 150 KIAS. Between 1,200 and 500 ft aal the rate of descent averaged approximately 3,000 fpm, and at 500 ft aal was 2,500 fpm. The aircraft’s TAWS generated six ‘pull up’ warnings on final approach. The aircraft crossed the threshold of Runway 25 at approximately 50 ft aal at 150 KIAS.
Tyre marks made by the aircraft at touchdown indicated that it landed approximately 710 m beyond the Runway 25 threshold. Runway 25 has a declared Landing Distance Available (LDA) of 1,059 m; therefore the aircraft touched down approximately 349 m before the end of the declared LDA, 438 m before the end of the paved runway surface
Data from the aircraft’s CVFDR indicated that the ground speed at touchdown was 135 kt and the airspeed was 134 KIAS. The aircraft manufacturer estimated that at this speed the landing ground roll required to stop the aircraft would be at least 616 m.
The aircraft departed the paved surface at the end of Runway 25 approximately three metres to the left of the extended runway centreline. It then collided with a one metre high earth bank causing the lower section of the nose landing gear and the nose gear doors to detach.
The aircraft became airborne again briefly, before colliding with several cars parked at an adjacent business and coming to rest approximately 70 metres beyond the earth bank. The aircraft’s wing detached from the fuselage during the impact sequence and an intense fire developed shortly thereafter, consuming the majority of the aircraft.
The aerodrome rescue and firefighting service attended the scene, followed by local emergency services. The four occupants were fatally injured.
The aircraft wreckage has been taken to the AAIB facility at Farnborough and the investigation continues with the assistance of representatives of the State of the Manufacturer and the State of the Operator of the aircraft.
The Saudi registered jet carrying three passengers from the Bin Laden family, was on a private IFR flight from Milan, Italy, with the 57 year old commander, who had 11,000 hours flying experience (1180 h on the type).
The aircraft powered by two Pratt & Whitney PW535E turbofan, was manufactured in 2010.
