ABOVE: Vertical has identified the root cause of the 9 August incident ‘to be a single component’

Vertical Aerospace, the Bristol-based company behind the VX4 eVTOL (electric vertical takeoff and landing) craft, has released an update regarding last month’s flight test incident.

In a story broken first by Pilot magazine, the VX4 prototype G-EVTL crashed during a flight test from Gloucestershire’s Cotswold airport, resulting in what appeared to be significant structural damage. Vertical subsequently confirmed that the incident occurred ‘during a motor failure test scenario, which is a key requirement to crewed operations,’ adding that ‘the aircraft was remotely piloted and there were no injuries’.

An update on the incident (dated 31 August) states that during the flight, when one of the aircraft’s electrical propulsion units had been disabled, ‘an unexpected fault occurred causing the aircraft to enter a stable descent, before being damaged on impact with the ground’. Vertical’s ‘swift and thorough’ investigation identified the root cause to be a fault with a bonding issue with the propellor blade, which had already been redesigned prior to the incident.

“While a fault of any sort is disappointing, it is not wholly unexpected at this stage of testing a novel aircraft,” explained Vertical founder and CEO Stephen Fitzpatrick. “I an pleased that as a result of our expert team we have isolated the cause of the fault and been able to provide the AAIB with our report within 14 days of the incident.” Believing ‘transparency and openness is fundamental to the safety aerospace,’ Vertical will be providing a ‘further full update to the industry once the AAIB’s investigation has concluded’.

Although the aircraft involved in the incident will not be repaired to an airworthy standard, it will continue to be used in further ground tests. Meanwhile, progress on the ‘assembly of a second significantly more advanced full-scale VX4 prototype’ (using a fuselage already supplied by Leonardo) continues at GKN Aerospace’s Global Technology Centre and is ‘expected to be ready to fly early next year’. The company remain confident that ‘the VX4 and its certification programme remains on track with no changes to timelines’,