On the morning of 16 October 1997, Boeing 767 ZK-NBC was prepared at Sydney (Kingsford-Smith) Airport for a flight to New Zealand. When one of the engines was found to be unserviceable, the passengers and their baggage were offloaded and placed on another flight. In anticipation of the aircraft becoming serviceable, two cargo containers were left in the cargo hold, one secured and one unsecured, and the hold doors were left open. When a change occurs to an aircraft's arrival or departure time, a delay checklist is used by operations staff to ensure that all departments are aware of the new time. Due to deficiencies in the delay checklist, a number of departments of the ground handling company were not advised of the new departure time.

So that repairs and engine runs could be performed, the aircraft was towed from the international terminal to the maintenance area. It is likely that the towing crew closed the hold doors at this time. The decision to move the aircraft was made without advising Ramp Control, who are responsible for the loading.

By late afternoon, new parts for the engine had been located, another flight crew was positioning from Auckland and a new departure time of 2300 hours was planned. A load instruction form was prepared by Load Control, covering the two cargo containers already on board and one additional container which was to be loaded. Ramp Control was not advised of the new departure time, assumed that the aircraft would depart the following morning and did not allocate a loading team. The aircraft was towed to the international terminal at about 2100 for refuelling, but the cargo hold doors were not opened. The load sheet officer reported receiving information that led him to believe that the additional cargo container would be loaded at this time. The flight crew arrived at the load control office to sign the load sheet. The load sheet officer assumed that the containers had been loaded in accordance with the load instruction report and signed the load sheet.

After refuelling, the aircraft with the flight crew onboard, returned to the engine run area for the fitment of parts and engine runs. It was declared serviceable at 2230. The flight crew started engines and taxied for takeoff from the maintenance area. At 2249, 11 minutes before the curfew at Sydney Airport commenced, the aircraft took off for its flight to Christchurch with no passengers onboard. After landing, when the cargo hold was opened, it was found that the unsecured container had moved around in flight but had not caused any damage to the aircraft.

Significant factors in this occurrence were:

1. Poor communications between a number of departments at Sydney Airport.

2. The failure of the load sheet officer to ensure that the aircraft had been loaded in accordance with the load instruction form before signing the load sheet.

3. The priorities of the load sheet officer which placed the departure of the aircraft before the curfew, ahead of adherence to the published loading procedures.

The ground handling agent advised that the following safety action has been carried out to prevent recurrence.

1. A review of the procedures for communications between departments at Sydney airport has been carried out.

2. The delay checklist, used by operations staff to advise departments of changes to aircraft times, has been reviewed.

3. New procedures that require the person responsible for loading to sign the load instruction form on completion of loading, have been introduced.

4. Written instructions have been issued to all ramp and load control staff confirming the operator's loading and documentation procedures.

5. Additional monitors have been installed in the load control and ramp control offices to keep staff advised of delays to aircraft arrival and departure times.

The pilot in command reported that the purpose of the flight was for continuation hover and taxi training for the student. The student had previously flown two hover flights. The weather was fine, and the flight had progressed for approximately 30 minutes.

The student's handling ability had improved to point that he was able to a hover over a fixed position on the ground. He was hovering the helicopter approximately 2 ft above the ground, when it began to yaw to the right and sink. The instructor told the student to apply left pedal, however, before the student or instructor could take recovery action, the tail rotor contacted the ground. The helicopter pitched up and fell back on the ground on the left side. After completing the emergency shut down checks, both the instructor and student were able to egress through the broken nose bubble without injury.

The pilot noticed as he flared the aircraft for landing that the landing gear was not extended. During the subsequent go-around scraping noises were heard. The aircraft was climbed to circuit height and the gear selector was recycled.

The subsequent extension of the landing gear was normal and the aircraft landed without further incident. Damage to the aircraft was confined to the inboard section of the right flap.

FACTUAL INFORMATION

A training flight had been planned for a Royal Australian Air Force (RAAF) General Dynamics F111 from Amberley to Amberley, incorporating a flypast of the Southern Cross school at Ballina East. The flypast was to consist of two overflights of the school. A notice to airman (NOTAM) for the low-level jet route of the F111 had been issued by the RAAF. The NOTAM did not indicate that the F111 would be operating in the area of the school. The route of the F111 to Ballina East was from a position 27 NM west-south-west of Ballina airport to over the airport at 1,500 ft above mean sea level and thence to Coolangatta on climb to 5,000 ft. The weather forecast for the flight indicated that there might be low cloud and showers in the Ballina area.

The crew of the F111 encountered low cloud and reduced visibility west of Ballina airport and descended to 1,000 ft above ground level. The crew made two traffic advisory radio broadcasts to notify aircraft in the Casino/Lismore/Ballina mandatory broadcast zone (MBZ) on the very high frequency (VHF) radio in accordance with Aeronautical Information Publication (AIP) procedures. The crew made a further transmission to notify personnel at the school of the F111's estimate over the school. This transmission was also made on the MBZ frequency. The last two advisory transmissions made by the F111 crew on the MBZ frequency were heard by the crew of a Boeing 737 on the ground at Ballina airport.

This crew also saw a Hughes Lightwing ultralight aircraft conducting circuit training on runway 24 at Ballina, although they did not hear the pilot make or acknowledge any radio broadcasts. The pilot of the Lightwing reported that he had made a taxi broadcast prior to conducting the circuit training. The AIP did not require the pilot to make other radio transmissions. Approximately 3 NM west of Ballina airport, the crew of the F111 encountered visual meteorological conditions (VMC) and tracked for the school. As the F111 passed south of Ballina airport abeam the western end of runway 24, the pilot in command saw the Lightwing to the left of his aircraft. The Lightwing was turning left and was at the same altitude.

Reports indicate that the lateral distance between the aircraft was somewhere between 300 m and 1000 m. Subsequently, the F111 crew contacted the pilot of the Lightwing and established that it had been at the same level. Both aircraft crew were unaware of the other aircraft prior to the visual sighting.

ANALYSIS

It was not determined why the other aircraft did not hear the taxi broadcast by the pilot of the Lightwing. Line of sight very high frequency transmissions may have been adversely affected by terrain shielding due to the low altitude of the F111 as it tracked to Ballina. However, the Lightwing pilot was not required to make regular calls on the MBZ frequency while conducting the training. Because they had not heard transmissions from each other, the pilots of the F111 and the Lightwing were not aware of the other aircraft operating in the MBZ.

The Skyfox Gazelle had undergone maintenance to rectify a flooding carburettor. The left side carburettor bowl had been removed and one of the floats found to be low. The carburettor was then removed and both carburettor floats replaced. The carburettor was re-installed, but when the fuel pump was turned on to prime the fuel system, the carburettor again flooded.

The maintenance organisation reported that the needle and seat were then adjusted until the flooding ceased. No evidence of flooding was found when the engine was ground run to full power, without the electric pump operating. Before commencing a subsequent test flight the pilot conducted another satisfactory full power check. However, shortly after take-off at about 200 ft, the engine lost power. The pilot commenced forced landing procedures, but the engine regained full power at about 100 ft. The pilot re-commenced climbing and returned to the airfield. But once again the engine lost power so the pilot force landed the aircraft on the airfield.

The resulting heavy landing bent the landing gear and damaged a wing tip. During a subsequent ground run the engine was able to attain full power. The left side carburettor was again removed and sent to the engine manufacturer's agent for disassembly and inspection. The inspection revealed that although the carburettor float level was slightly incorrect, it was not considered sufficient to cause the engine to lose power. However, the carburettor air duct was found to be holed and both the needle and float mechanisms were excessively worn. Those components were replaced, and the carburettor re-installed. The fuel system was then pressurised using the electric fuel pump.

The left side carburettor was found to be operating correctly, but the right-side carburettor now flooded. The right side carburettor air duct was subsequently found to be holed, and the needle and seat were excessively worn. It is considered that the combination of holed air ducts and worn carburettor needles and seats probably resulted in an excessively rich fuel mixture, with an associated loss of engine power. The maintenance organisation has supplied a report to CASA.

A Cessna 310, VH-DWS, was maintaining 7,000 ft outbound from Kalgoorlie to Forrest via the standard instrument flight rules (IFR) route. VH-LAE, a Cessna 402, was maintaining 10,000 ft from Forrest to Kalgoorlie, also on the standard IFR route. Both aircraft were between reporting points Sevsi and Seemo, in cloud, and were using high frequency (HF) radio to communicate with Perth Flight Service (FS). At approximately 1236 WST, the pilot of LAE requested traffic for descent to 6,000 ft because the aircraft had encountered icing conditions, but the HF communication conditions were poor and FS did not understand the request. The next 6 minutes were spent by FS trying to establish communications with LAE. In the meantime, LAE had commenced descent to clear the conditions, unaware of the existence of DWS. The pilot of LAE reported that he had made a general broadcast on HF and very high frequency (VHF) radios before commencing descent, although the broadcasts were not recorded by FS or heard by the pilot of DWS. At approximately 1243, DWS was given traffic information on LAE. The pilots of the two aircraft then contacted each other on the area VHF frequency and established that LAE and DWS had crossed and were now 11 NM apart at 6,000 ft. LAE had passed through DWS's level on a reciprocal track. The separation between the aircraft as they crossed could not be established.

In reviewing the Aeronautical Information Publication (AIP) communication procedures, it was noted that although dual (HF and VHF) area broadcast requirements are specified in the AIP Air Traffic Rules and Services (RAC) section, the Operations (OPS) section does not detail the same requirement. OPS 58 specifies the radio telephony requirements outside controlled airspace without including the dual broadcast procedures.

SAFETY ACTION

As a result of this investigation, the Bureau issued Safety Advisory Notice SAN980018 to the Civil Aviation Safety Authority (CASA) on 26 February 1998. This Safety Advisory Notice alerted CASA to the inconsistencies in the AIP regarding the requirements for radiotelephony reports on both HF and VHF radios in non-controlled airspace.

A response was received from the Civil Aviation Safety Authority on 12 May 1998, which stated:

"CASA has reviewed the information provided in the Safety Advisory Notice and will amend the AIP as BASI has proposed".

BASI response status: Closed - Accepted

FACTUAL INFORMATION

A foreign Boeing 747 (B747) was being sequenced for landing on RWY 16 at Melbourne aerodrome by the Departures North radar controller (DEPN). After landing, the pilot in command of the B747 rang the Area Approach Control Centre (AACC) and queried whether the aircraft had received a clearance to land.

A check of the tower audio voice recording (AVR) tape revealed that the Aerodrome controller (ADC) had issued a landing clearance but that the transmission had not been acknowledged by the crew of the B747. Further checks of the AVR for the DEPN position found that the DEPN controller had not instructed the crew of the B747 to transfer to the ADC frequency.

The AVR also indicated that the crew did not query the DEPN for the need to transfer to the ADC frequency as the aircraft approached the runway. The crew of the B747 left the aircraft radio selected to the DEPN frequency during the landing.

The Aeronautical Information Publication (AIP) stated that the clearance limit for an aircraft approved to make an instrument approach was the nominated runway, subject to further air traffic control instructions and a clearance to land. The crew of the B747 continued the flight beyond the clearance limit without requesting a clearance to land or further instructions. The AIP also stated that a pilot in command must not land unless the specific clearance "Cleared to land" had been received.

The ADC would normally receive an acknowledgement of the receipt of a landing clearance from the flight crew. The ADC did not challenge the crew of the B747 when the clearance to land was not acknowledged.

Three controllers normally staffed the control tower. On the day of the occurrence there were only two controllers on duty as one controller had been rostered to relieve at another location. Due to a misunderstanding a replacement controller was not nominated. The controllers on duty in the tower believed that staffing was adequate for the expected traffic and did not request a replacement controller. The two controllers were required to share the responsibility for the conduct of coordination while operating their respective positions of ADC and Surface Movement control (SMC).

ANALYSIS

The reasons for the crew of the B747 not querying the DEPN controller with respect to the need to change to the ADC frequency and for the DEPN controller not instructing the crew to change to the ADC frequency, were not determined.

The ADC was distracted by coordination duties to the detriment of his prime function. Consequently, he did not ensure that the B747 was operating on the ADC frequency prior to issuing a clearance to land. He also did not challenge the crew of that aircraft to acknowledge receipt of the clearance.

SIGNIFICANT FACTORS

1. The DEPN controller did not instruct the crew of the B747 to transfer to the ADC frequency.

2. The crew of the B747 did not query the DEPN controller regarding transfer to the ADC frequency as the aircraft approached the runway.

3. The ADC did not query the DEPN controller with respect to the frequency transfer of the B747 when the aircraft was on final for the runway.

4. The ADC did not establish that the B747 was on the frequency prior to issuing a clearance to land.

5. The ADC did not obtain an acknowledgement of the clearance to land from the crew of the B747.

6. The crew of the B747 landed the aircraft without obtaining a clearance to land from the ADC.

The student pilot was conducting solo crosswind circuits in a Cessna 172, on runway 23 at Maitland NSW. During a landing sequence, the aircraft touched down heavily and bounced.

The student then used an inappropriate recovery technique that resulted in a second heavy touchdown on the nosewheel. The propeller, cabin floor and firewall suffered damage as a result of the impact.

The pilot of the Cessna 172 aircraft made a normal approach in light wind conditions for runway 21. During the landing roll, the aircraft initially tracked to the right side of the runway before slewing heavily to the left. As a result, the propeller struck the runway, bending the tips of both blades back at right angles.

A maintenance investigation did not reveal any defects that may have contributed to this occurrence.

The pilot of the Piper Seneca advised that after a normal approach and landing at Hopetoun Vic he sensed that the nose landing gear was retracting. He stated that he recycled the landing gear lever to ensure that the gear was down but the nose continued to lower as the nose landing gear collapsed. Concurrent with this the right main gear also retracted and the aircraft settled just off the strip. The pilot and his three passengers were able to evacuate successfully. Shortly after the accident the pilot commented that he had three greens on approach, and that he was now aware that recycling the landing gear selector was not the optimum action that could have been taken.

The pilot later advised that he had been told that it was possible that the nose landing gear could have retracted due to being out of adjustment, and that the right main landing gear could have retracted as a consequence of the hydraulic pressure being generated by the collapsing nose landing gear. The pilot also stated that he and his front seat passenger were now sure that he had not recycled the landing gear selector during the accident sequence.

Discussion with maintenance organizations found that there has been various causes for Piper Seneca nose landing gear malfunctions, maladjustment being just one of the causes. However, the landing gear system is such that the down locks need to be selected before they release.

A detailed examination of the aircraft will be undertaken after the aircraft has been recovered to a maintenance facility.