Aviation safety investigations & reports

Collision with terrain involving an Insitu ScanEagle X200 unmanned aircraft system (UAS) near Woleebee Creek, Queensland, on 9 January 2019

Investigation number:
AO-2019-004
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

At about 0825 Eastern Standard Time on 9 January 2019, an Insitu ScanEagle X200 (X200) unmanned aircraft system was launched to conduct ‘beyond visual line of sight’ aerial survey work in the Woleebee Creek area of Queensland. The flight crew consisted of two pilots and two ground crew.

Shortly after launch, one of the ground crew observed the X200 pitch up and then enter an aerodynamic stall. The flying pilot commenced the emergency procedures for a stall-spin, however the X200 self-recovered before the checklist was completed. At about the same time the pilots received an alert indicating an airspeed sensor failure and initiated the associated emergency procedure checklist.

Before visual sight was lost, the ground crew observed the X200 oscillating in pitch as it continued to fly to the programmed first waypoint. While the flying pilot was executing the emergency procedures checklist, the X200 entered a second aerodynamic stall. Following self‑recovery from a low height above terrain, the X200 commenced a climbing orbit. Shortly after, the X200 entered a third aerodynamic stall, this time from a height that was insufficient for recovery, and collided with terrain. There was no post-impact fire and the X200 was destroyed. There were no reported injuries to people or damage to infrastructure. A post-incident inspection of the X200 identified a partial blockage in the pitot system.

What the ATSB found

The investigation found that the blockage in the pitot-static system resulted in unreliable airspeed data being supplied to the autopilot. Unreliable airspeed data led to the X200 entering an aerodynamic stall at a height that was insufficient for recovery.

During the pre-flight checks, there were opportunities for the erroneous airspeed indications to be identified. However, they were not recognised by the crew or flagged by the ground control station.

What's been done as a result

Following the occurrence, the manufacturer revised their procedures to reduce the risk of aircraft being affected by a pitot blockage. Additionally, all of the operator’s pilots underwent refresher training. This included emergency procedures simulator experience.

The X200 manufacturer revised their procedures to provide support to pilots and ground crew in correct assembly of the articulated turret, identifying anomalies (on the ground and in-flight), and steps for aircraft recovery in the event of a departure from normal flight. In addition, updates to the operational software would ensure any spurious on‑ground anomalies were alarmed, to prevent the X200 being launched with an unidentified issue.

Safety message

This occurrence highlights the importance of confirming the significance of any unexpected observations during the pre-flight checks, to minimise the risk of the aircraft departing with an unserviceability. In addition, providing pilots and ground crew with the reasoning behind specific checks and procedures can enhance their ability to identify anomalies and perform the appropriate corrective actions in a timely manner.

Insitu ScanEagle X200

Insitu ScanEagle X200. Source: Insitu Pacific

Source: Insitu Pacific

Download final report
[Download  PDF: 1.23MB]
 
 
 

The occurrence

General details
Date: 09 January 2019   Investigation status: Completed  
Time: 0830 EST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): near Woleebee Creek   Investigation phase: Final report: Dissemination  
State: Queensland   Occurrence type: Collision with terrain  
Release date: 15 August 2019   Occurrence category: Accident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft model Insitu ScanEagle X200 unmanned aircraft system (UAS)  
Aircraft registration Call sign AV616  
Serial number 08-616  
Operator Insitu Pacific  
Type of operation Aerial Work  
Sector Remotely piloted aircraft  
Damage to aircraft Destroyed  
Departure point Woleebee Creek area  
Destination Woleebee Creek area  
Last update 15 August 2019