Lithium battery main cause of crash in which glider fell apart mid-air, Civil Aviation Authority report finds

Lithium battery main cause of crash in which glider fell apart mid-air, Civil Aviation Authority report finds
Photo credit: File.

A 2017 glider crash in Kaikohe that killed the 72-year-old pilot was caused by an in-flight battery fire, according to a report released by the Civil Aviation Authority (CAA).

On Thursday, the CAA released its safety investigation report into the incident involving glider ZK-GEL, which determined "fumes and smoke" would have most likely filled the cockpit and caused the pilot to lose control after the lithium polymer battery caught fire, before the glider started to break apart in the air.

Here’s what happened: 

On November 16, 2017, at 1.40pm, the pilot launched his Pipistrel Taurus Electro G2 glider from Kaikohe aerodrome. Sometime between 2.15pm and 5.30pm, a fire broke out while the glider was mid-air. 

Lithium battery main cause of crash in which glider fell apart mid-air, Civil Aviation Authority report finds
Photo credit: Civil Aviation Authority

The glider was making an emergency descent and approach to Kaikohe aerodrome when it exceeded speed limitations. This led to structural failure of the wings and the glider broke apart, the report says. 

Lithium battery main cause of crash in which glider fell apart mid-air, Civil Aviation Authority report finds
Photo credit: Civil Aviation Authority

The pilot - who was a member of the local gliding club - held a glider pilot certificate and private pilot helicopter licence. He had 592 hours experience on gliders, with 87.9 hours on the glider ZK-GEL.

Lithium battery main cause of crash in which glider fell apart mid-air, Civil Aviation Authority report finds
Photo credit: Civil Aviation Authority

The battery was a part of an Electro 40/30 electric motor used for self-launch take-offs and sustain flight. The glider was destroyed and the pilot was killed. The crash was considered "not survivable". It is the first recorded battery fire onboard a glider to occur in New Zealand.

"The CAA is warning aviators that batteries must be charged and properly maintained according to the manufacturer’s instructions. If battery damage is suspected due to a sudden impact they must be checked before flying again,” Aviation Safety Deputy Chief Executive Dean Winter said in a statement from the CAA.

"Battery fires burn at a very fast rate releasing significant energy and toxic fumes. Within seconds a cockpit can be filled with toxic smoke. These fires can be deadly and spread quickly."

At the time of the accident there were no other battery-powered gliders in NZ. 

"We are also concerned any lithium polymer battery in any device or aircraft can cause a fire," Winter said.