Thursday, May 18, 2017

Slingsby T67M Mk II Firefly, G-BNSO: Fatal accident occurred April 30, 2016 in North Yorkshire, United Kingdom



An investigation has concluded that a fatal plane crash near Castle Howard was likely caused by the pilots being unable to pull out of a spin.

Ajvir Singh Sandhu, 25, and Cameron Forster, 21, died when their plane crashed into a field near the stately home close to Malton, just after 9.30am on April 30 last year.

The Air Accidents Investigation Branch (AAIB) has now published its findings into the fatal accident and to what may have caused the 30-year-old Slingsby T67M MKII Firefly to crash.

The report found that there were no faults with the aircraft and also said investigators were unable to ascertain which of the men was the pilot at the time of the crash, as the plane had dual controls.

However, it was noted that one of the pilots had been trained on how to recover a spin in another type of aircraft, a Tucano, which required a procedure that was different to that of the Slingsby.

The report concluded: “The extensive damage to the aircraft was wholly consistent with a high-energy impact with the ground. Examination of the aircraft and its systems found no evidence to suggest the aircraft had suffered a structural failure or technical malfunction which could have contributed to this accident.

“The investigation established that, when found, both occupants were holding their respective control column but it was not possible to establish which occupant was handling the aircraft at any point during the flight.

“Given that the aircraft may have been in the process of recovering from the spin in the very last moments of the descent, it is possible that an incorrect spin recovery technique was used as the requirement to move the control stick progressively forward is a critical element of the spin recovery action in the Slingsby T67.

“This was not a requirement for spin recovery the Tutor or Tucano; aircraft on which the pilot had previously received spin training. It is possible that if the pilot initially adopted the technique applicable to those aircraft, the spin recovery would have been delayed.”

It added that the weather was “suitable” for the intended acrobatics.

On the day of the crash, one eyewitness said she saw the plane “spiralling downwards in a corkscrew movement” as she drove near Castle Howard.

In December, an inquest into the deaths recorded a verdict of “accidental death”, with “pilot error” and not a mechanical reason likely for the failure to pull out of the spin.

Mr. Sandhu and Mr. Forster were both trainee pilots at RAF Linton on Ouse, where they flew Tucano planes.

They had chartered the Firefly privately from Full Sutton airfield near York to practise aerobatic manoeuvres.

Post-mortem examinations found that Mr. Sandhu, from Essex, died instantly from blunt head injuries and Mr. Forster, from West Sussex, died from torso injuries.

Coroner Michael Oakley noted that the plane was not carrying parachutes, something the pilots were under no legal obligation to do.

He said: “This plane was not carrying a parachute. That’s something I consider does need perhaps looking at.”

“Similarly, the issue has been made with regard to the specific spin training.

“There’s the issue that every aircraft may have its own idiosyncrasies and clearly this aircraft does have that.”

The family of Mr. Sandhu claimed during the inquest that the plane was known as “a flying coffin and a “widow maker”, with 48 deaths recorded since 2009.

Story and photo gallery:  http://www.yorkshireeveningpost.co.uk

Accident report - Air Accidents Investigation Branch: https://assets.publishing.service.gov.uk

Synopsis

The aircraft, operating in the vicinity of Castle Howard, North Yorkshire, was engaged in a general handling flight which included aerobatics. It was seen by witnesses in the area and recorded on radar. One witness saw the aircraft carry out a loop and, having passed the apex of the manoeuvre, enter what appeared to be a spin. The aircraft did not recover from the spin and struck the surface of a ploughed field, fatally injuring both persons on board.

History of the flight

The pilot and a friend arrived at Full Sutton airfield at about 0830 hrs. The pilot had booked G-BNSO for two flights that day; the first was for general handling and aerobatics and the second, later, was to take family members flying. The weather was good with a light westerly wind, good visibility in excess of 10 km and broken cloud at about 3,000 ft. 

Both the pilot and his passenger were students on the Tucano phase of their RAF flying training and had flown the Grob Tutor, a light piston-engine aircraft, during their initial flying training. 

With the assistance of other club members, they pulled the aircraft out of the hangar and then went into the clubhouse and completed the booking-out form. The Chief Flying Instructor (CFI) joined them at the aircraft and checked the fuel and oil levels whilst the pilot carried out the pre-flight inspection, watched by his passenger. Whilst he did not look at the fuel gauges, the CFI estimated that there was 1.5 hours fuel in the left wing tank and 1.0 hours fuel in the right wing tank, based on the engine consuming 45 litres of fuel per hour whilst performing aerobatics.

Another pilot, who had met the G-BNSO pilot and passenger when they had first arrived at the club, was taxiing back to the parking area having flown two circuits when he heard them call for a radio check and airfield information. There was no reply, so he passed them the information he had received earlier. That pilot switched off his engine at 0915 hrs and by that time G-BNSO was at the holding point carrying out the power checks. Shortly after this, the aircraft was seen to backtrack Runway 22 and depart.

A full radar track and Mode C heights of the aircraft were recorded as it climbed through 200 ft after takeoff and, following a right turn, tracked towards Castle Howard. Witnesses in the vicinity of the southern part of Castle Howard estate heard or saw the aircraft. A couple, who were close to the scene in their garden, saw the aircraft perform a loop. On the downward half of the manoeuvre the aircraft appeared to enter a spin, during which the engine was initially heard to “cut out” but then it appeared to restart, before cutting out again. The witnesses lost sight of the aircraft as it descended behind the roof of an outbuilding but they then heard the sound of an impact. Other witnesses reported a similar “corkscrewing” motion before the aircraft struck the surface of a ploughed field, initially with the nose and right wing, in a steep nose-down attitude. The pilot and passenger, who were fatally injured were each found to be holding the top part of their respective control sticks, which had broken off in their hands. The pilot was holding the left stick with both hands and the passenger the right stick with just his right hand.

Accident report - Air Accidents Investigation Branch: https://assets.publishing.service.gov.uk

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