Aviation safety investigations & reports

Kavanagh Hot Air Balloon D-105, VH-BOK, 5km NE of Cessnock Airport NSW, 15 October 1989

Investigation number:
198900017
Status: Completed
Investigation completed

Summary

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Towards the completion of a scenic flight with five adult passengers on board, the pilot descended the balloon to a height of approximately 200 feet above ground level and commenced searching for a suitable landing site. His initial selection was subsequently abandoned to avoid frightening an injured horse. The balloon with limited fuel remaining continued at low level, passing over timbered country before commencing a deflated landing into a semi-cleared area. The area was surrounded by tall trees to the left, right and rear of the flight path. A two-wire high voltage set of powerlines located just ahead of the pilot's proposed landing area, were not sighted by a ground retrieval crew member, who was in the vicinity of the landing site and in radio contact with the pilot, nor apparently by the pilot until late into the landing.

The passengers had not been briefed to assist in observing for and reporting powerlines. The pilot then issued instructions which his passengers understood to mean that they prepare to exit the balloon basket. When approximately one metre above the ground, the first passenger evacuated the basket followed by the pilot, who had the fabric covered metal parachute vent line wrapped in a spiral around his forearm. With the load reduced the balloon began to ascend. One flying wire supporting the balloon basket at the lower section of the balloon envelope, contacted the powerlines before the balloon descended again. An electrical discharge was heard and one powerline was severed. As the basket neared the ground a second and third passenger exited. The pilot was then observed lying on the ground fatally injured, apparently having received a high voltage discharge via the parachute vent line. The line had then detached from around his forearm. A fourth passenger then vacated the basket, leaving one passenger on board. With the release of the parachute vent line the exhaust vent closed and as there was still sufficient buoyancy retained within the envelope, the balloon slowly re-ascended. When at an estimated height of 10 metres above the ground, the remaining passenger was observed to fall from the balloon basket and receive fatal injuries. The balloon continued to drift for approximately two kilometres before settling to the ground in heavily timbered country. The pilot's technique of wrapping the parachute vent line around his wrist and forearm would have made rapid deflation difficult. His actions in preparing passengers to jump and his decision to exit the basket prior to landing, were totally alien to the normal and emergency modus operandi. It is believed that a previous similar type fatal accident involving a balloon colliding with a powerline, may have influenced his behaviour. Subsequent trials indicated that it is extremely difficult to evacuate all passengers from a basket in a short time frame without pre-warning, established drills, and orderly implementation.

The weather conditions were calm and clear but the early morning ambient light conditions would have made detection of the powerlines difficult. The area selected for the landing was the only alternative available considering the meteorological conditions and fuel remaining. The size of the area, should have been within the capabilities of the pilot and balloon had there been no powerlines across the flight path. Stringent obstacle clear gradient requirements exist for the selection of take-off sites, but not for landing sites. Despite some instrumentation deficiencies, the balloon and all of its relevant equipment was serviceable, and had been maintained in accordance with approved procedures. Electrical bonding and insulation properties of the balloon were considered to be inherent design deficiencies for this type of aircraft, thereby permitting differing electrical potentials to exist between individual components, particularly in the event of powerline contact.

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General details
Date: 15 October 1989   Investigation status: Completed  
Time: 715    
Location: 5km NE of Cessnock Airport    
State: New South Wales   Occurrence type: Wirestrike  
Release date: 28 September 1990   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft details

Aircraft details
Aircraft manufacturer Kavanagh Balloons  
Aircraft model D  
Aircraft registration VH-BOK  
Serial number KB-027  
Type of operation Ballooning  
Damage to aircraft Minor  
Departure point 9 km N of Cessnock Airport NSW  
Departure time 0600  
Destination 5 km NE of Cessnock Airport NSW