History of the Flight
The pilot and passenger had flown from Weston, Ireland, to Turweston Aerodrome in Northamptonshire and intended to return the same day. Prior to departure from Turweston, the pilot contacted several aerodromes for weather information and discussed conditions with the Turweston aerodrome manager, sourcing meteorological data from the internet. The aircraft was fuelled to full tanks, and the pilot performed a pre-flight inspection with no defects found. He carried out pre-flight checks including removal of the split pin from the Ballistic Recovery System (BRS) activation handle and a test of the autopilot system.
The aircraft departed at 1428 UTC. Airfield staff estimated the cloud base at about 1,700 ft and visibility of 10 km or more between passing showers. The pilot established the aircraft on track towards LIPCO, contacted Birmingham Approach, and indicated his intention to cruise at 4,500 ft. At 1436 UTC, the controller asked for the aircraft type; the pilot replied with a broken transmission identifying the aircraft as a "sierra romeo two zero" and then stated, "just pulled the 'chute – we're ok." Shortly after, he transmitted, "we're descending over open ground - under parachute – we inadvertently went imc." The controller marked the aircraft's location and alerted emergency services. No further communications occurred.
The aircraft descended under the BRS parachute and impacted a tree on common ground near a village. The tree restricted the right side cabin door, but both occupants exited via the left door without difficulty. Neither occupant sustained injury, and there was no fire. Members of the public assisted. The pilot made a 999 call to the Police, stating he had "lost control." Fire and rescue personnel addressed a fuel leak from a ruptured tank.
Pilot's Recollections
During interviews with an AAIB investigator, the pilot stated that after departing Turweston, he engaged the autopilot in vertical speed and navigation modes. Approaching 3,000 ft, he decided the weather ahead was unsuitable, selected altitude hold, and pre-selected the heading bug for a 90° turn. He then turned his attention to the GPS screen to programme a return to Turweston. He reported a "huge jolt" that dislodged his headset, and he found himself looking straight down at the ground. He checked the airspeed (120 kt), closed the throttle, and pulled the BRS activation handle. He later added that he attempted to pitch the nose up before activating the parachute but the aircraft did not respond. He pulled the handle firmly and sustainedly; the parachute deployed with a loud rustling sound and took longer than expected to influence the aircraft's motion.
During the parachute descent, the pilot saw the aircraft drifting toward a built-up area. Recalling a previous event in the USA where engine power was used to steer under parachute, he restarted the engine and attempted to steer, though he was uncertain of the effect. The aircraft drifted away from the built-up area, so he shut down the engine and electrical system. He described the descent as "very gentle."
In the initial interview, the pilot did not mention entering IMC. After hearing the RTF recording, he stated he had not entered IMC but made the transmission to indicate he was turning because of cloud ahead.
Pilot Training
The pilot obtained a PPL(Aeroplanes) in 2007 and completed two days of Cirrus conversion training with a Cirrus certified instructor, which included autopilot use. He acknowledged not understanding some autopilot selections. He had no memory of a BRS briefing but was familiar with the system description in the aircraft documentation and was aware of the maximum demonstrated deployment speed (132 kt, as he stated; the POH specifies 135 KIAS). He had no qualification for flight in IMC.
Meteorological Information
The Met Office analysed conditions near Hornton at the time. Satellite and radar imagery placed Hornton on the boundary between thick cloud to the south and more broken cloud to the north. An observation at the nearest station (Coventry) showed cloud base lifting from 1100 UTC, but Hornton likely experienced lower cloud bases and poorer conditions. The chief flying instructor at Shennington Gliding Club (2 nm southwest) recalled that at about 1430 hrs, flying ceased due to low cloud, rain, and drizzle, with cloud base 800-1,000 ft and visibility about 1,500 m. Sky cleared after 30-45 minutes.
Recorded Data
The aircraft was equipped with an Avidyne Entegra PFD and MFD. Data reading showed that autopilot parameters were not recorded due to the software version. Recording began at taxi at Turweston and ended on the ground following the accident. GPS positions and pressure altitude were used to plot the accident track. Accelerations from the PFD were converted to 'g' and corrected to the aircraft's centre of gravity.
ATC and Emergency Services Response
The controller did not initially recognize that "pulled the 'chute" referred to a BRS parachute but quickly deduced the aircraft was descending under parachute. The investigation noted that air navigation service providers have not been formally informed of the development of ballistic recovery systems; some staff are aware, others are not.