Aviation safety investigations & reports

Rolladen-Schneider Flugzeugbau GmbH LS6-B, VH-HDT

Investigation number:
199805348
Status: Completed
Investigation completed

Summary

The two gliders were taking part in the Australian National Gliding Championships at Narromine NSW. One, a German registered Rolladen Schneider LS8A glider, registered D-1003 was flown by a British national, while the other, an Australian registered Rolladen Schneider LS6B glider, VH-HDT, was flown by a Japanese national. Both pilots complied with the Gliding Federation of Australia (GFA) requirements for foreign nationals operating in Australia.

Although some gliders in the competition had self-launch capability, both gliders involved in the accident were launched by aero-tow. The 52 gliders competing on the day were launched in approximately 45 minutes. Launching commenced at mid-day with D-1003 being launched at 1225. After release at 2,000 ft AGL the pilot manoeuvred to take up a position near start point "Charlie" from where he would start the day's task. Shortly before the accident D-1003 was observed to be steadily banking to the right in a thermal at approximately 6,000 ft AMSL, in the company of at least six other gliders.

VH-HDT was launched at 1230 and at approximately 1315 was observed to be approaching from the south-west, flying fast, and manoeuvring to join those gliders circling near start point "Charlie". HDT was seen to bank to the right to conform to the established circling direction within the thermal. Concurrent with banking to the right HDT pulled up sharply, directly below D-1003. Immediately prior to the collision, HDT's angle of bank was observed to rapidly reduce. The cabin section of HDT was observed to collide with the lower centre and forward fuselage of D-1003. The structural integrity of the forward fuselage of HDT was destroyed and the forward fuselage was observed hanging approximately 20 degrees below the normal fuselage line. The glider descended vertically, rotating to the right, before impacting the ground and coming to rest inverted. The pilot did not survive the collision.

The post mortem examination did not disclose any abnormalities that may have contributed to the accident.

The pilot of D-1003 advised that he had not sighted HDT approaching the thermal. He felt and heard a huge impact concurrent with D-1003 pitching violently nose down. The pilot immediately released the canopy and seat harness before parachuting clear. D-1003 descended in a flat spin to impact inverted 200 metres from HDT. The pilot landed a further 200 metres away, sustaining back injuries during the landing.

The wreckage of both gliders was examined and no pre-impact fault was found in either glider. The examination confirmed that HDT had impacted the lower fuselage of D-1003. There was some evidence of intermeshing of the wings during the collision sequence, however the structural integrity of the wings was probably not greatly compromised by the collision.

The on-board data recorders were recovered and examined. Because of impact damage to security switches within the units, all recorded data had been lost.

Both pilots involved in the accident had been assigned to start the task at start point "Charlie". Start point Charlie was approximately 15 km north of the town of Narromine and had been allocated to 13 of the competing gliders on the day of the accident. A start point is a GPS position based on a geographical feature that the pilot must transit in order to register a start for the day's task. After passing though the start point the pilot reports the start time and allocated point to the competition organisers by radio. An on-board recorder that is interrogated for verification by the competition organisers also records the start time and position.

The organisers had nominated four start areas for the day. The four start areas were dispersed at locations up to 20 km from the airfield. Within each start area were five geographical start points. Each pilot was issued with a randomly selected list of four valid start points, one from each area. The pilot could use any one, but only one, of these four start points. This created a double dispersion: a scatter of start areas, and a scatter of start points within those areas. The use of multiple start areas and start points was introduced to eliminate the overcrowding of airspace that occurred when just one start point was used.

Approximately 20 minutes after the last glider is launched the organisers declare the points open which signals to the pilot's that they can, in their own time, commence the day's task. The start points were not open at the time of the accident. The system of multiple start points has been deemed successful in reducing the incidence of congestion within the start area and on the competition task.

The pilot of HDT was wearing sunglasses and was looking through four facets when observing features and events outside of the canopy. At the time of the accident the sun was essentially overhead, the sky was clear and visibility was unlimited. There would not have been an impediment to the vision of the pilot of HDT as he approached the thermal from the south-west. Neither the pilot's visual acuity nor the weather were considered to be factors in the accident.

The pull up when entering a thermal is a manoeuvre used by glider pilots to convert forward speed to height. There are certain etiquette's surrounding the approach to an occupied thermal and these form part of the training undertaken by all glider pilots. The pilot of HDT was highly experienced; he was a gliding instructor in Australia and Japan, and he had taken part in many national and international gliding competitions. Accordingly he would have been aware of the factors to be considered when joining the thermal. It is not known why the pilot of HDT did not observe the position and flight path of D-1003 while approaching the thermal. D-1003 was essentially on a consistent flight path within the thermal and should have been visible to the pilot of HDT.

HDT was equipped with reasonably sophisticated navigation and communications systems. It may be that the pilot was attending to this equipment while approaching the thermal and did not notice D-1003 until after initiating the pull up. The rapid change to the angle of bank observed just before impact was probably the initiation of an unsuccessful avoidance manoeuvre by the pilot of HDT.

Safety Action

Local Safety Action

As a result of this accident the GFA is considering a review of start point procedures, and a review of visibility from, and of, gliders.

The GFA will also review the use of advanced avionics in gliders in an endeavour to determine if programming and interrogating of those systems is distracting the pilots from their primary task of visual collision avoidance.

General details
Date: 25 November 1998   Investigation status: Completed  
Time: 1315 hours ESuT    
Location   (show map): 13 km N Narromine, Aero.    
State: New South Wales   Occurrence type: Airborne collision  
Release date: 20 February 1999   Occurrence category: Accident  
Report status: Final   Highest injury level: Fatal  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer Rolladen-Schneider Flugzeugbau GmbH  
Aircraft model LS6  
Aircraft registration VH-HDT  
Type of operation Gliding  
Damage to aircraft Destroyed  
Departure point Narromine, NSW  
Departure time 1230 hours ESuT  
Destination Narromine, NSW  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command 4000

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer Rolladen-Schneider Flugzeugbau GmbH  
Aircraft model LS8  
Aircraft registration D-1003  
Type of operation Gliding  
Damage to aircraft Destroyed  
Departure point Narromine, NSW  
Departure time 1225 hours ESuT  
Destination Narromine, NSW  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command 1700
 
Injuries
  Crew Passenger Ground Total
Fatal: 1 0 0 1
Serious: 1 0 0 1
Total: 2 0 0 2
Last update 13 May 2014