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.

The aircraft was being used to spray crops approximately 600 m from the strip being used for take-offs and landings. The aircraft engine lost power during a spray run and the pilot elected to land straight ahead into the field of barley. After touchdown, the aircraft ground looped, causing some damage to the port wing trailing edge and aileron. The pilot noted after landing that the fuel transfer warning light was illuminated and he later found that there was only a small amount of fuel in the main fuel tanks.

The pilot reported that he had noted the aircraft's low fuel state before take-off but decided to fly until the fuel transfer warning light illuminated. The fuel transfer warning light illuminates when the fuel pressure at the inlet to the header tank falls below approximately 14 kpa for a sustained period, indicating that the mechanical fuel pump is not delivering fuel to the header tank or that the main fuel tanks have run dry. The pilot believed that he could return to the strip before fuel exhaustion caused the engine to fail.

With regard to the fuel transfer warning light, the aircraft flight manual states in part: "In the latter case, although the contents of the header tank has been declared "unuseable fuel" due to certification regulations, the remaining 12 litres of fuel in the header tank should in fact be available and sufficient for at least 12 minutes of further flight at normal power settings and aircraft attitudes". The aircraft was fitted with a Global Positioning System (GPS) tracking bar with a series of red lights to indicate lateral displacement from the desired flight path.

The GPS bar assists the pilot to correctly align the swath runs. The pilot reported that each of the GPS bar lights was similar in appearance to the fuel transfer warning light located in the coaming above the instrument panel. The fuel transfer warning light glowed a steady red when illuminated. The GPS bar was mounted in the accident aircraft such that it was directly in the pilot's line of sight, appearing just to the left of, and very near to, the fuel transfer warning light. The pilot reported that during the spray runs, he was concentrating on avoiding powerlines and was referring to the GPS bar.

He had not noticed the illumination of the fuel transfer warning light during the flight. The pilot noted after landing that the fuel transfer warning light was on; therefore, it had probably operated correctly. However, because the pilot's attention was drawn to avoiding powerlines as well as using the GPS bar, he failed to notice the illumination of the fuel transfer warning light during the flight. The proximity and similiarity of the GPS bar lights to the fuel transfer warning light probably contributed to the pilot not noticing the illumination of the fuel transfer warning light.

The pilot's decisions to rely on the fuel transfer warning light and to plan the use of the header tank fuel were probably encouraged by the aircraft's flight manual wording on unuseable fuel. The wording indicates that the unuseable fuel is useable.

SAFETY ACTION

The Bureau is considering the safety implications of the wording contained in the aircraft flight manual regarding the use of "unuseable" fuel from the header tank. Any safety action arising from the investigation of this matter will be forwarded to the relevant action agencies and will be published in the Bureau's Quarterly Safety Deficiency Report.

The aircraft departed two minutes apart from Kalgoorlie enroute to Perth. The first aircraft, BAe 146 VH-NJZ, was cleared by the sector air traffic controller to track via Southern Cross on planned route climbing to FL240. The route followed the 255 degree radial from the Kalgoorlie VOR. When the pilot of the second aircraft, Boeing 737 VH-CZP, contacted the sector controller for a clearance, he advised that the aircraft was avoiding weather and tracking the 240 degree radial from Kalgoorlie VOR. The sector controller subsequently cleared CZP to track via the Nalar Dulya route on climb to FL350.

The pilot of CZP was communicating with the pilot of NJZ on the flight service frequency to ensure separation was maintained between the aircraft during the weather avoidance. The FSO reported to the sector controller that the pilot of CZP advised that he was initially tracking outbound on the 257 degree radial from the Kalgoorlie VOR and was now paralleling track. When queried by the sector controller, the pilot of CZP advised that the aircraft was on approximately the 246 degree radial from the Kalgoorlie VOR and was leaving FL210 on climb. The controller instructed the pilot of CZP to maintain FL210, to which the pilot replied that the aircraft was leaving FL220 on descent to FL210. The pilot of NJZ was immediately queried by the sector controller about his altitude and he reported that his aircraft was leaving FL225 on climb.

The investigation revealed that it was unlikely that a breakdown in separation occurred because the pilots appeared aware of their relative positions and maintained separation. However, the sector controller took action to ensure procedural separation was maintained based upon the information available to him.

Piper Chieftain aircraft, VH-RDL, departed Boonoke (a property near Deniliquin) on a charter flight to Sydney in accordance with the Instrument Flight Rules, with a planned intermediate refuelling stop at Cootamundra. As the aircraft approached the Cootamundra circuit area the left engine began to surge. The pilot commenced a straight-in approach to the 10 grass runway, however the right engine also began to surge and lose power.

The aircraft was landed in a paddock, some 400 metres before the beginning of grass strip 10. During the ensuing ground roll the pilot was able to manoeuvre the aircraft over a shallow creek bed and a fence. The aircraft then passed through the aerodrome boundary fence before stopping on the runway. The nine passengers and pilot escaped without injury. The aircraft was substantially damaged.

During a subsequent examination of the aircraft it was determined that all useable fuel had been exhausted from both inboard tanks. The left outboard fuel tank contained 11 litres, while the right outboard tank contained 30 litres.

The Chieftain was one of a number of aircraft chartered to carry a large group of people to and from Boonoke during the weekend of 18-19 October. On the evening of 17 October, the operator briefed all pilots associated with the proposed charter on how the operation was to be conducted. During the briefing the operator said that he had arranged with fuel agents at Deniliquin and Cootamundra to provide fuel as required. Fuel purchases were to be placed on the operators account. Refreshments had also been arranged for passengers at Cootamundra while refuelling was taking place.

On the afternoon of 18 October VH-RDL was ferried from Bankstown to Sydney, having departed Bankstown with some 602 litres of fuel, comprised of full inboard tanks, and 100 litres in each of the two outboard tanks. After arriving at Sydney another pilot took command of the aircraft and flew nine passengers to Deniliquin. No fuel was added to the fuel tanks after the aircraft left Bankstown.

The following afternoon VH-RDL, which had remained at Deniliquin, was scheduled to take nine passengers from Boonoke to Sydney. A pilot who had flown another Chieftain, VH-XML, from Sydney to Deniliquin the previous evening, was tasked to carry out the return flight in VH-RDL. Prior to departing Deniliquin the pilot he said he carried out a Daily Inspection. His first action was to turn on the master switch and check the fuel contents indicators. He also opened both inboard tank caps to carry out a visual contents check. Although the tank interiors were in shadow he thought he could just see fuel, but he could not touch it. Based on his observations, and a comparison of the estimated fuel burn from Bankstown, he estimated the fuel remaining totalled 280 litres, whereas he had calculated he required 257 litres to fly to Cootamundra via Boonoke, including appropriate fuel reserves. The pilot also said that it was his understanding from the earlier briefing that each aircraft should carry sufficient fuel from Sydney to allow a return to Cootamundra via Boonoke before refuelling. He believed that it was preferable not to refuel at Deniliquin, although he felt that if he needed fuel it would not have been a problem obtaining it.

Another pilot reported that he spoke to the pilot of VH-RDL prior to the flight and suggested that the aircraft be refuelled prior to departing from Deniliquin, to eliminate the need to land en-route. However, the pilot of VH-RDL indicated he would refuel at Cootamundra, which would also provide for a passenger "comfort stop".

The aircraft was duly flown to Boonoke, to take on passengers, before departing for Cootamundra. After take-off the aircraft was climbed to its planned cruising altitude of 9,000 ft, drawing fuel from the inboard tanks. Once established in level flight the outboard tanks were selected and fuel was drawn from those tanks until commencing descent, some 16 minutes before the estimated time of arrival at Cootamundra. At about that point the pilot moved the fuel selectors to draw fuel from the inboard tanks. He said the outboard fuel contents gauges were indicating empty, and he had been monitoring the engine exhaust gas temperature gauges for initial indications of exhaustion of the outboard tanks. However, no indications were noticed before he reselected the inboard tanks, in accordance with a Flight Manual limitation to only use the outboard tanks in level flight. The pilot said he thought the inboard fuel tank contents were indicating between 1/4 and 1/2 full. At that stage he said he had no concerns about the amount of fuel remaining.

As the aircraft approached the Cootamundra circuit area the left engine began to surge. The pilot looked at the left fuel gauge and noted it was indicating below 1/4. He selected the left outboard tank and turned on the boost pump. The engine continued to surge briefly before operating normally. He then turned off the boost pump. At that point the aircraft was at an altitude of some 3,500-4,000 ft. Shortly after, the left engine again commenced to surge. The pilot said he again turned on the left boost pump and moved the fuel selector to run both engines from the right inboard tank via the fuel crossfeed.

With the aircraft still descending the pilot elected to carry out a straight-in approach to land on the 10 grass runway, joining final approach at an altitude of about 3,000 ft. Because the aircraft appeared to be high the landing gear was extended. However, both engines began to surge and lose power. Because the pilot was unsure if the aircraft could reach the runway threshold he elected to land short in an adjoining paddock, progressively extending flap prior to touchdown.

A subsequent investigation found that Chieftain, VH-XML, had carried out a similar flight to VH-RDL, from Sydney to Cootamundra, via Deniliquin and Boonoke. However, that aircraft had departed Sydney with full tanks, and was found to have used 551.17 litres upon arrival at Cootamundra. The useable capacity of both inboard and outboard tanks of the Chieftain totals 690 litres. The fuel remaining in VH-RDL after the accident was 41 litres. When compared to the fuel burn of VH-XML, the total fuel on board VH-RDL when it departed Sydney would have been about 590 litres.

The actual fuel carried in the aircraft on departure from Boonoke was probably about 190 litres, some 67 litres less than the minimum fuel required, including reserves.