Posted: Thu 29th Oct 2020

‘No definitive cause’ found in plane crash which killed retired Bangor University professor

North Wales news and information
This article is old - Published: Thursday, Oct 29th, 2020

No definitive caused has been found of a plane crashed which killed a retired Bangor University academic.

Professor David Last died on the 25th of November last year, when his light aircraft crashed and was lost at sea close to Puffin Island off the eastern tip of Anglesey.

He was said to be an experienced instrument-rated pilot, for many years owning his own aircraft and often flying himself and others around North Wales and overseas.

A report published by the Air Accidents Investigation Branch (AAIB) today said Mr Last “was on a local flight when it descended into the sea.”

The report has found that no “definitive cause” for the accident could be found and “there was no evidence of a structural failure leading to the accident.”

Prof Last arrived at Caernarfon Airport at about 9.15am on the day of the accident, having booked that morning to fly a The Cessna 172S7 with the flying club based at the airport.

He checked the weather and booked out with the flying club before going out to the aircraft at about 09.25 am.

The engine, however, would not start, an engineer examined the aircraft and identified the starter motor shear pin had failed.

“Whilst the engineer worked on the aircraft, the pilot returned to the flying club where he talked to a number of people who described his demeanour as being normal,” The AAIB report states.

About an hour later the aircraft had been repaired and the Prof Last started the engine and taxied for takeoff departing at 11.15 am

He planned to complete a local flight from Caernarfon out to the Great Orme, returning via Puffin Island off the north-east coast of Anglesey; a flight of about 30 minutes.

Shortly after becoming airborne Prof Last contacted Caernarfon enquiring whether RAF Valley was open.

Caernarfon Radio replied that it was and the pilot replied he was changing frequency to RAF Valley.

The pilot contacted ATC at RAF Valley jst before 11.30am explaining he was on “a short trip to the Orme and back” asking for a Basic Service.

RAF Valley Air Traffic Control acknowledged his request.

The aircraft flew up the Menai Straits and continued to follow the mainland coastline and climbed to 1,500 ft as it turned left towards Great Orme, before turning left again towards Puffin Island.

Personnel at the flying club offices checked progress of the flight using the app Flightradar24 just after 12pm.

They could not see the aircraft on the live feed so they searched the playback feature on the app which showed the aircraft “apparently disappearing” in the vicinity of Puffin Island.

Flying club staff then asked Caernarfon Radio to put out a call to the pilot, but there was no response. Growing concerned, they phoned RAF Valley Air Traffic Control which also tried to contact Prof Last, there was no reply.

At 12.35pm RAF Valley “notified the Distress and Diversion Centre which initiated overdue action.”

A search was commenced using lifeboats and a search and rescue helicopter.

Debris was found floating in an area north-west of Puffin Island later that afternoon.

During the search for the aircraft, a lifeboat crew found the aircraft’s right wing part of the nose landing gear, a first aid kit and some personal effects floating in the sea approximately 3 miles north-west of Puffin Island.

An attempt by the lifeboat crew to recover the wing was abandoned when it came into contact with the lifeboat, puncturing the side.

After the immediate search and rescue attempts had been called off, a seabed search for the missing aircraft was commenced using vessels equipped with sonar.

A survey of the area found the wreckage of an aircraft, approximately one mile off the north-east tip of Puffin Island in about 27 m of water.

The aircraft was not recovered, but video from a Remotely Operated Vehicle (ROV) subsequently confirmed it was the wreckage of the plane.

The body of Prof Last was recovered on 12th December last year.

Inboard end of the right wing found floating in the sea

A review of the aircraft’s maintenance records did not reveal any significant issues the AAIB report states.

“The work carried out during the recent service and the repair to the starter motor just prior to the flight are unlikely to have resulted in any problems leading to a loss of power or inability to control the aircraft.”

AAIB carried out a trial to replicate the final flight profile which discounted a full or partial engine failure.

“The trial concluded that it was likely the aircraft required an input on the controls in order to enter and maintain the recorded final descent path.”

The report goes onto to say that “the pilot had recently been unwell but there was no evidence of medical incapacitation, although this could not be dismissed as a possible cause.”

The post-mortem and toxicology tests did not reveal any indication that the pilot had become incapacitated, although it is still possible that this had occurred.

The pilot had been unwell in the days before the flight and his complaint of feeling uncomfortable when the car he had been travelling in had accelerated was unusual.

His family had however considered he was well again at the time he went flying and saw nothing unusual in his behaviour.

Had the pilot become incapacitated during the flight it is likely he would have released the controls.

The flight test demonstrated that the aircraft should then have entered a spiral dive rather than the near constant track descent seen on flight data.

Of note, it is probable that had a technical problem occurred, or the pilot suffered some kind of incapacitation such as a sudden migraine attack, the pilot would have attempted to notify Air Traffic Control by radio.

In conclusion the AAIB said “it has not been possible to identify a definitive cause of the accident.”

“Whilst only a remote visual examination of the aircraft was possible, there was no indication of structural failure and the flight trial conducted indicated an engine failure had not occurred.”

“The stability of the aircraft and evidence from the flight trial points to the need for an input on the controls, if only slight, to both enter and maintain a descent along a nearly constant track, as well as turning the aircraft left and then right towards the end of the descent.”

“There was no evidence of medical incapacitation of the pilot, however, his recent illness and the fact that causes of incapacitation are not always evident means that this cannot be excluded.”



Spotted something? Got a story? Send a Facebook Message | A direct message on Twitter | Email news@north.wales

More...

Denbighshire village set to expand with 22 new homes at former training centre

Denbighshire

Denbighshire Responds to Care Home Owner’s Criticism of Council Leader

Denbighshire

Eco-friendly underground dwelling plans near Menai Strait set to go before Anglesey planners

Anglesey

Conwy to Introduce Parking Charges at Free Car Parks After Budget Cuts

Conwy

Councillors call for more gritting on Great Orme roads

Conwy

Plans Submitted to Create Studio Flat Above Fast Food Restaurant on Wrexham’s High Street

Wrexham