Aviation occurrence briefs

Collision with terrain involving Ayres Corporation S2R, 5 km north of Dalby, Qld, on 21 December 2018

Number:
AB-2018-132
Status: Completed
Investigation completed

Brief

Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.

What happened

On 21 December 2018, the pilot, and sole occupant of the Ayres Corporation S2R departed Dalby, Queensland to conduct aerial agriculture spraying.

During initial climb, at about 200 ft above ground level, the aircraft did not respond to control inputs to climb further. The pilot turned right to avoid hitting obstructions but found the aircraft was not performing in the way he expected. The pilot attempted to climb by increasing the throttle to maximum and lowering the nose of the aircraft to increase airspeed, but the aircraft was unable to maintain height.

As the aircraft’s airspeed decreased, the pilot experienced wallowing[1]. The pilot attempted to drop the chemical load to lighten the aircraft’s weight, but the aircraft did not respond. The pilot then lowered the nose of the aircraft to conduct a forced landing. The aircraft entered a stall and subsequently impacted a row of trees resulting in substantial damage and minor injuries to the pilot.

Figure 1: Ayres Corporation S2R post accident
Figure 1: Ayres Corporation S2R post accident. Source: Chief Pilot

Source: Chief Pilot

Safety message

This accident highlights the importance of monitoring and checking instruments during flight, to ensure aircraft speed and performance is maintained. As aircraft speed reduces and approaches Vmca[2], low speed controllability of the aircraft becomes very difficult. Pilots and operators are also reminded of the need to ensure that the aircraft’s weight is within limits and maximum take-off weight to ensure the on-going safety of the aircraft and operations.

The pilot involved in this accident was required to make important decisions in a short period of time, including where to land and how to manage the remaining altitude. Pre-flight self-briefing is an important tool in reinforcing planned emergency actions.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

 

__________

  1. Wallowing - Uncommanded motion about all three axes of an aircraft occurring simultaneously.
  2. Vmca - Minimum control speed in the take-off configuration minimum control speed.
General details
Date: 21 December 2018   Investigation status: Completed  
Time: 0500 AEST    
Location   (show map): 5 km north of Dalby    
State: Queensland    
Release Date: 19 February 2019   Occurrence category: Accident  
Report status: Final    

Aircraft details

Aircraft details
Aircraft manufacturer Ayres Corporation  
Aircraft model S2R  
Type of operation Aerial Work  
Sector Piston  
Damage to aircraft Substantial  
Departure point Dalby, Queensland  
Last update 19 February 2019