Aviation safety investigations & reports

Loss of control and collision with terrain involving YAK-9UM, VH-YIX, 19 km west-north-west of Latrobe Regional Airport, Victoria, on 7 September 2018

Investigation number:
AO-2018-061
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 7 September 2018, the pilot of a Yakovlev 9-UM (YAK 9) aeroplane, registered VH-YIX, departed Latrobe Regional Airport, Victoria for a local private flight. The aircraft was observed by witnesses to the north of Moe, Victoria performing aerobatic manoeuvers. A short time later the aircraft impacted the ground in a steep nose‑down attitude, fatally injuring the pilot and destroying the aircraft.

What the ATSB found

The ATSB found that the aircraft entered a spin at low altitude from which it was not possible to recover. There was no evidence of pilot incapacitation, or a mechanical fault with the aircraft that contributed to the accident.

The pilot had limited experience and recency in the YAK 9 and had not previously conducted aerobatics in the aircraft. He was therefore likely unaware of its unique handling characteristics and not adequately prepared to conduct the solo aerobatic flight.

The ATSB also identified a number of other factors that, while not contributory, increased safety risk. These included inadequate aircraft maintenance and operation without important flight and maintenance documentation.

Safety message

This accident highlights the inherent risks associated with performing low-level aerobatics in high performance aircraft. Pilots engaged in such flights are encouraged to observe minimum approved operating heights above the ground, commensurate with their ability and qualifications, and to engage in regular flight reviews and/or flight instruction.

Pilots should also ensure that careful preparation and planning is undertaken prior to each flight and that all documentation, checklists and required manuals are appropriately stored and accessible within the aircraft.

Download final report
[Download  PDF: 990KB]
 
 
 

The occurrence

Context

Safety analysis

Findings

Additional details

Sources and submissions

Preliminary report

Preliminary report published: 15 November 2018

What happened

On 7 September 2018, a Yakovlev Aircraft Factories YAK-9UM aircraft, registered VH-YIX (Figure 1), was being operated on a private flight from Latrobe Regional Airport, Victoria. The pilot/owner of the aircraft was the sole occupant.

The aircraft departed the airport at about 1425 Eastern Standard Time.[1] Recorded air traffic control data showed that the aircraft initially tracked from the airport to the west toward Morwell, climbing to about 2,600 ft and heading north-west near Moe.

Several witnesses described seeing the aircraft conducting aerial manoeuvres to the north of Moe and video footage from a witness showed the aircraft in a steep spiralling dive shortly before it collided with terrain (Figure 2). Other witnesses described seeing the aircraft moments prior to the accident with the engine ‘not revving very loudly’, and ‘making popping noises’. The aircraft was destroyed, and the pilot was fatally injured.

Figure 1: Yakovlev Aircraft Factories YAK-9UM aircraft, registered VH-YIX

Figure 1: VH-YIX. Source: Mike Yeo- jetphotos.net

Source: Mike Yeo- jetphotos.net

Site and wreckage examination

On-site examination of the wreckage and surrounding ground markings indicated that the aircraft impacted terrain in a right-wing low, nose‑down attitude. The tail of the aircraft separated from the fuselage during the accident sequence. Both wings, the forward fuselage and the cockpit were substantially disrupted and compressed from vertical impact forces. An extensive area surrounding the accident site was contaminated with fuel that was released when the wing tanks ruptured. The degree of propeller damage observed on-site was consistent with the engine producing a level of power at the time of impact.

The ATSB recovered a number of components from the accident site for further examination. The aircraft was not equipped with a flight data recorder or cockpit voice recorder, nor was it required to be.

Figure 2: VH-YIX aerial picture of accident site

Figure 2: VH-YIX aerial picture of accident site. Source: ATSB

Source: ATSB

Ongoing investigation

The investigation is continuing and will include consideration of the:

  • pilot’s qualifications, experience and medical history
  • recovered aircraft components
  • maintenance documentation
  • operational documentation
  • witness interviews
  • electronic devices recovered from the aircraft.

 

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The information contained in this update is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB's understanding of the accident as outlined in this web update. As such, no analysis or findings are included in this update.

 

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  1. Eastern Standard Time (EST): Coordinated Universal Time (UTC) + 10 hours.
General details
Date: 07 September 2018   Investigation status: Completed  
Time: 1432 EST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): 19 km WNW, Latrobe Regional Airport (near, Tanjil South)   Investigation phase: Final report: Dissemination  
State: Victoria   Occurrence type: Collision with terrain  
Release date: 17 June 2020   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft details

Aircraft details
Aircraft model Yakovlev Aircraft Factories - YAK-9UM  
Aircraft registration VH-YIX  
Serial number 0470409  
Type of operation Private  
Sector Piston  
Damage to aircraft Destroyed  
Departure point Latrobe Valley, Victoria  
Destination Latrobe Valley, Victoria  
Last update 17 June 2020