The pilot was positioning the aircraft from Adelaide Airport to Parafield where he was instructed to join the circuit on right base for a landing on runway 08L. When the landing gear was extended the nose gear down light failed to illuminate. The pilot initiated a go around and attempted to obtain a safe indication by recycling the gear using both normal and manual methods, but without success.

An inspection from the ground indicated that the nose gear leg was trailing about 30 degrees, which was verified by the pilot of another aircraft flying close by who advised that all the gear retracted normally, but the nose gear trailed when extended.

A decision was made to land the aircraft with the gear retracted to minimise damage.

An investigation revealed that the forward retract drive tube was severely bent, and the rear drive tube bowed. This prevented the nose gear from fully extending.

The reasons why drive tubes were bent could not be determined. The aircraft may have suffered a heavy landing on the nose gear, or it may have been extended very late on the previous landing, with the nose wheel contacting the ground just prior to the gear locking into the down position, bending the tubes, but still with enough energy to engage the down lock. The pilot who flew the aircraft previously denied any knowledge of an abnormal landing.

During a practice touch and go landing, the aircraft ballooned during the flare. The pilot applied some power to prevent a subsequent heavy touchdown/bounce and persisted with the landing attempt. She said that she was then distracted by the proximity of a runway strip marker on the left side of the aircraft. The pilot lost directional control of the aircraft, and a ground loop ensued.

At 0812, VH-CZL departed runway 16 at Melbourne on a 16 Cowes 5 departure with instructions to maintain 3000 ft. This departure involves tracking 170 deg until through 2500 ft or four miles DME and then tracking direct to Cowes which is on the Melbourne 150 deg VOR radial. After CZL made contact with departures control, the aircraft was cleared to climb to flight level 370.

At 0813, N61CF departed from runway 17 at Essendon heading 170 deg and initially limited to 3000 ft. At 0815 CZL left 5000 ft and N61CF was cleared to climb to 4000 ft. Shortly afterwards N61CF was instructed "at 4000 ft turn right heading 260 deg".

At 0816, N61CF was observed in a right turn and climbing through 4700 ft. At this time CZL was climbing through 5500 ft with N61CF less than two miles away and closing. N61CF was asked to confirm maintaining 4000 ft and passed traffic on CZL. The pilot of N61CF advised the traffic was in sight and apologised for the transgression.

The pilot was taxiing the aircraft for take-off at the time of the accident. He had just completed refuelling at the fixed fuel bowser and was turning the aircraft to the right when it collided with a refuelling cart that had been positioned to refuel a regular public transport aircraft that was expected to land shortly. The impact crushed a section of the wing's leading edge and then, as the cart rolled over it punched a hole in the lower surface of the wing fuel tank.

The cart had been repositioned by the fuel agent between the time the pilot completed refuelling and when he taxied the aircraft. The cart had not been there when he taxied in, and he was not expecting it to be there when he taxied out. The Glassair aircraft has a tailwheel, and forward visibility is partly restricted. The pilot was speaking to the crew of the regular public transport aircraft, to establish their intentions, as he taxied out and this probably distracted him. He also reported that he was not feeling well, and this may have reduced his concentration.

The aircraft was landing on a loose gravel surface runway with a crosswind from the left at 10 - 15 kt. During the landing roll the aircraft veered to the right and the pilot took corrective action in an attempt to return it to the centreline. The aircraft started to recover, but due to skidding on the loose gravel surface it was too late to prevent the right main gear leg from striking a runway flare unit made from steel bore casing welded to a steel base plate, standing 300 mm high, causing the gear to collapse.

The helicopters main rotor blades came into contact with a tree during a low-level fence inspection operation. The helicopter then descended out of control into a flooded river and submerged. The pilot and observer egressed safely from under the water.

The pilot reported that he had manoeuvred the aircraft to within about 10 metres of some tall trees beside the river, in order to give the observer the best possible view of a section of fence. At this point the helicopter yawed left and the main rotor blades struck a tree. Later the pilot said that he though the tail rotor blades may also have struck a tree. After the tree strike the pilot had insufficient control and was unable to prevent the aircraft descending sideways into the river.

The wreckage was not recovered from the river for several weeks, due to flooding and continuing torrential rain. Later examination of the wreckage did not reveal any pre-existing mechanical fault which may have contributed to the accident. The tail rotor assembly was found to be intact and attached to the boom. No evidence was found to indicate the tail rotor blades came into contact with the tree.

The pilot reported that he had accumulated about 6.5 hours flying for the day as well as having spent time on the ground on business at a number of locations. It had been very hot and turbulent throughout the day. He was relieved when he reached the Newman circuit and relaxed as the flight was nearly over. He joined the circuit on downwind and made a general downwind broadcast on MBZ frequency. The pilot thought he had completed the downwind checks correctly, but subsequent events indicated he had forgotten to lower the landing gear. During his finals checks he noticed that the landing gear lights were not illuminated but he assumed he had forgotten to turn the brightness back to the daytime setting. He realised the gear was still up when the propeller started to hit the ground. The landing gear warning horn, which had not sounded during the circuit, came on as the aircraft settled onto its lower fuselage.

The pilot reported that the landing gear waring horn may have been intermittent prior to the accident. He had made a note on the maintenance release to have it checked at the next periodic service which was due when the aircraft arrived back in Perth.

The pilot indicated that he felt that the factors leading to the accident were very straight forward. He was fatigued after a long day and had relaxed too much when he reached Newman. He had not payed sufficient attention to the operation of the aircraft and his fatigue had led to him rationalise the lack of landing gear lights as a rheostat setting rather than an indication the gear was still up. The failure of the landing gear warning horn to sound aggravated the situation.

FACTUAL INFORMATION

A Boeing 727 aircraft was en route from Melbourne to Brisbane via Casino and Coolangatta at flight level (FL) 350, while a Boeing 767 aircraft was en route to Brisbane from Sydney via BANDA and Coolangatta at FL370. The Boeing 767 was east of the Boeing 727's track and a few minutes behind on time estimates. There was a holding requirement at Brisbane with instrument landing system approaches in progress due to reduced visibility in passing rain showers.

The Brisbane sector radar position responsible for controlling the two aircraft was manned by a trainee controller undergoing final checks prior to rating. The trainee was being supervised by a current sector controller. However, the supervising controller was not the regular training officer for the trainee, and this was the first occasion that they had worked together. The Boeing 727 was initially vectored in a northerly direction for separation from other traffic but was shortly after instructed to turn right onto a north-easterly heading for arrival sequencing at Brisbane. The trainee controller intended to maintain the Boeing 727 on the north-easterly heading and provide a final heading to Coolangatta to meet the time required for sequencing. The Boeing 767 entered the controller's area of responsibility, and the crew requested descent to FL330 due to moderate turbulence.

The Boeing 767 was recleared to FL330. The new level was read back and the crew reported leaving FL370. The supervising controller discussed with the trainee the requirement to ensure separation between the two aircraft, since they were on converging tracks with the Boeing 767 crew cleared to descend through the Boeing 727's level. Discussion centred on whether the Boeing 767 should be radar vectored to parallel the track of the Boeing 727 until the required vertical separation of 2,000 ft was established. However, as there was more than sufficient horizontal separation (minimum separation required was 5 NM), the trainee controller elected to leave the Boeing 767 under the crew's navigation and to monitor the situation. The supervising controller believed it was reasonable to allow the trainee a level of latitude for independent action greater than he normally would for a trainee as the trainee controller had almost completed training. As separation between the two aircraft reduced to approximately 15 NM, the trainee controller's attention was diverted as he conducted coordination with another control position. As horizontal separation approached 8 NM and vertical separation was approximately 700 ft (with the Boeing 767 below the level of the Boeing 727) the trainee controller instructed the crew of the Boeing 767 to turn right onto a heading to parallel the track of the Boeing 727.

During this transmission the trainee controller incorrectly advised the Boeing 767 crew that the radar heading was for sequencing, instead of separation. The trainee controller requested the crew of the Boeing 767 to expedite descent and to confirm that the aircraft was turning right. The crew advised that the aircraft was turning right and expediting descent and, shortly after, reported sighting the Boeing 727 as horizontal separation reduced to approximately 4 NM with vertical separation of 1,600 ft. Horizontal separation reduced further to just over 3 NM before 2,000 ft vertical separation was re-established. The operating console was not fitted with an air-ground-air communication override facility to enable the supervising controller to intercede in trainee transmissions. Traffic information was not provided to either aircraft as the horizontal and vertical separation reduced to less than the standard. There was no Traffic Alert and Collision Avoidance System (TCAS) report from the B767. ANALYSIS The trainee's use of the term "sequencing" instead of "separation" did not provide the level of notice to the crew of the Boeing 767 that was warranted under the circumstances. Had the crew been advised that the heading change was for separation they may have been more expeditious in complying. However, the situation should not have been allowed to develop to the stage where immediate action was required to maintain separation.

Similarly, the inclusion of a console facility that would enable the supervising controller to override the trainee's transmissions to establish appropriate separation measures would have been beneficial. But again the situation should not have developed to the extent that such facilities were essential. Both controllers had discussed separation requirements for the two aircraft, and the trainee was satisfied with monitoring the situation. The supervising controller deferred to the trainee's judgement because he understood the trainee was close to achieving a rating. However, the trainee became distracted, and the supervising controller did not adequately monitor the trainee's subsequent control actions.

The supervising controller could have emphasised to the trainee the need to give priority to the radar display and to maintain a high scan rate to ensure separation. However, the situation would have been still totally dependent on the performance of the trainee and the supervisor. As the trainee became distracted by coordination to the detriment of control, the supervising controller was unable to intervene adequately, and separation was lost between the aircraft. Monitoring of the flight paths did not provide an adequate level of separation assurance. Early implementation of an altitude requirement or a radar heading (to parallel the track of the Boeing 727) to the crew of the Boeing 767 would have been an adequate separation assurance technique. Use of separation assurance techniques would have greatly improved the possibility of the two aircraft remaining separated.

SIGNIFICANT FACTORS

1. The supervising controller did not adequately monitor the trainee controller's actions or ensure that a suitable separation assurance technique were employed.

2. The use of inappropriate radiotelephony phraseology by the trainee controller did not impart to the crew of the Boeing 767 the need for expeditious compliance with instructions.

3. The lack of a communications override facility deterred the supervising controller from implementing timely remedial action.

SAFETY ACTION

The Bureau of Air Safety Investigation is continuing its investigation into the provision of adequate communications override facilities for air traffic control training officers. This is intended for all consoles where on-the-job training of air traffic controllers is likely to occur.

The crew were carrying out rappelling recurrency training at the time of the accident. During the first of several planned descents down the rope, from 70 ft, the rescue crewman misjudged his speed and landed heavily, resulting in a fracture of his right leg.

The speed during descent is normally controlled by the degree of braking applied to the rope by one hand. The braking required is judged on 'feel' through the glove. The rescue crewman was wearing two pairs of gloves as the pair he normally wore were slightly frayed. He had previously only worn a single pair during rappelling activities. It is probable that the extra pair of gloves altered the 'feel' causing the crewman to misjudge his descent rate.

The crew were all endorsed for rappelling activities, a pre-flight briefing had been completed, and activities were being conducted in accordance with the operations manual. However, the rescue crewman's rappelling currency had lapsed.

Safety Action

The operator has introduced a flying safety instruction requiring crew, who's currency in rappelling has lapsed, to complete at least three descents from a suitable static platform prior to helicopter operations. In addition, the first rappel from the helicopter will be completed from 30 ft instead of 70 ft.

The operator is also researching the use of mechanical braking devices as an alternative to the 'feel' system.

The purpose of the flight was to aero tow a glider from a paddock where it had made an out landing. Prior to take-off the pilot measured the paddock twice by pacing. The paddock was wedge shaped with powerlines running along the two longer boundaries. There was also a powerline spanning the paddock towards the narrow end of the wedge. Despite walking under this powerline while pacing the paddock, the pilot did not see it.

Take-off was into the northwest which provided the longest take-off run and was also into a 5-7 kt wind. After take-off the pilot held the tug down to gain speed. He then saw the powerline but too late to avoid it. After impact with the powerline the tug hit the ground and was substantially damaged.

The pilot said that in the take-off direction, the powerline was below the horizon against a background of hills which made it almost impossible to see.