FACTUAL INFORMATION

The aircraft departed Broome on a short-notice charter to transport seven passengers from Derby to Cadjebut. The flight to Derby was uneventful and the passengers were boarded for the trip to Cadjebut. Apart from a small amount of surging from the right engine after start, the start, taxi and line up were normal. The pilot assessed the surging to be the result of low RPM after start and noted that the surging disappeared as RPM increased. He saw no discrepancies during the magneto checks on taxi.

No problems were encountered in the take-off until about 150 ft above ground level, when the pilot assessed that the right engine had failed. The landing gear was already retracted and the pilot commenced emergency drills for an engine failure after takeoff. He stated that there was insufficient time to feather the propeller and that the aircraft did not climb. It eventually impacted the ground and slid to a stop over mud and through low mangrove bush.

The passengers and pilot evacuated the aircraft. After the pilot had notified Air Traffic Services that the aircraft had crashed, he made the aircraft safe, and he and the passengers walked to the airport.

An on-site inspection did not reveal any defects or circumstances which could have contributed to an engine power reduction or the subsequent landing on the mud flats. Impact marks on the ground from the propellers supported the contention that the right engine was not delivering the same power as the left engine. The strike marks indicated that the right engine RPM was approximately half that of the left engine at initial impact with the ground.

The right engine was transported to Perth where it was successfully ground-run on an engine rig. The engine was subsequently dismantled, and extensive tests were performed on components which could have contributed to the perception by the pilot and several of the passengers that the engine had failed or had significantly reduced its power output. These tests centred mainly on the turbocharging, electrics and the fuel systems. Anomalies were only discovered in the dual magneto. However, the anomalies could not be directly connected to the power reduction.

The reason for the power reduction thus remains undetermined.

The aircraft was at, or marginally over, the maximum weight for take off when the power reduction occurred. The density altitude when the pilot commenced his emergency drills was about 2,000 ft and the pilot had not been able to feather the right propeller before the aircraft impacted the ground. The pilot operating handbook performance data suggested that with the right propeller feathered, the aircraft may have been able to climb at a rate of about 180 ft/min under ideal circumstances. The handbook does not provide information on the effect of not having a feathered propeller on the inoperative engine.

Emergency locator transmitter

A NARCO ELT10 was fixed in the rear of the fuselage and was correctly armed. The ELT did not activate, probably due to low-impact forces on the mud flats. The beacon was not needed as the pilot made radio contact with a flight service officer and the crash was observed by another aircraft.

ANALYSIS

Studies have shown that the combination of high weight, high density altitude and added drag from an unfeathered propeller can all reduce the climb performance of a light twin-engined aircraft in the event of an engine failure. Results of some of these studies were publicised during the 1996/97 Civil Aviation Safety Authority Flight Forum Series and the results indicated that an unfeathered propeller could reduce the rate of climb on a representative PA 31 by between 100 and 200 ft/min. It therefore follows that this aircraft was unlikely to have been able to maintain a positive rate of climb if the engine completely failed.

Although it is not known to what extent the engine power was reduced, the propeller marks indicate an RPM reduction in the order of 50% from take-off RPM, which suggests a substantial loss of useful power and possibly a windmilling propeller. This, and the performance data above, would probably explain the inability of this aircraft to climb away.

The aircraft was taking off from an agricultural strip for a rice sowing flight, carrying 1,000 kg of rice seed. The aircraft became airborne momentarily before settling back onto the strip. The pilot was unable to stop the aircraft before it collided with a low fence and a contour bank.

There were active thunderstorms reported in the area at the time, and it is likely that the aircraft encountered adverse windshear during lift-off.

The aircraft was engaged in spraying operations over a crop of rock melons. The pilot had not previously sprayed crops at this farm. During one of the spray runs the right wing struck a thin metal pole located at the edge of the paddock. The pilot was able to maintain control of the aircraft and diverted to land safely at a nearby air strip.

The farmer who normally removed the steel pole had forgotten to remove it on this occasion or to notify the pilot of its location.

The 5 to 6 m high pole was constructed of 25 mm square steel tubing. The pilot later said that he saw the obstacle too late to avoid a collision.

The pilot stated that the helicopter was given a full daily inspection. The engine had full oil and there was approximately 55 litres of fuel on board. After start, the engine was kept at idle until oil temperature was about 75 degrees. the rotors were then engaged and warm up was continued at 2000 RPM and then 2500 RPM. The magneto check showed no rough running. After pre-take-off checks, the helicopter was brought to the hover and moved forward about 6 feet, then put back on the ground for about 3 minutes while a load was placed on board. The pilot stated that after checking that all nozzles were working and pre-take-off checks were complete, he brought the helicopter to the hover. At 3200 RPM the manifold pressure was 26 inches. Transition to forward flight was normal, and height and speed began to increase. At about 60 to 70 feet agl and about 40 knots the engine note changed, and the pilot noticed RPM had reduced to about 2700. The pilot lowered the collective and wound on full throttle. A landing straight ahead was carried out with some forward speed, and during the landing the main rotor struck the tail boom and severed it. The helicopter was fitted with an NARCO 10 Emergency Locator Transmitter, which did not activate during the heavy landing.

Subsequent examination of the engine failed to reveal any defect, but engineering opinion was that the engine malfunction was most likely due to a sticking valve.

FACTUAL INFORMATION

An international B747 was enroute from Singapore to Melbourne over northwestern Australia at flight level (FL) 350. The B747 was under the control of a Brisbane sector controller using procedural control. The Brisbane controller was a team leader and he had commenced work at 2300 EST. He conducted a performance check on another controller until 0200 at which time the other controller left the console for a break. The team leader continued operating the position for approximately another two hours. The team leader felt well except for a minor cold condition which had developed that afternoon.

Generally, the work at the sector, on the evening shift, could be divided into approximately three periods. The first period was from 2300 until 0100 and this was the time when departure and position reports for aircraft intending to transit the sector were mainly received from northern air traffic control centres. The period from 0100 until 0200 was when the boundary positions were received. The last period from 0200 to 0400 was when the aircraft actually entered the sector and the crews contacted the sector controller. On the day of the incident the last period had finished at approximately 0300.

The B747 had been cleared to operate at FL350 and the crew had requested a preferred level of FL370 after 0320. The crew of the B747 reported their position at Curtin at FL350 and with an estimate for PAVKO of 0336. The team leader co-ordinated the position report with a Melbourne sector controller. PAVKO was the point at which control of the aircraft would be transferred from Brisbane to Melbourne air traffic control. The team leader intended to approve the crew of the B747 to climb to the higher level and to co-ordinate the level as FL 370 with the Melbourne controller. However, the team leader co-ordinated the level as FL350. The Melbourne controller incorrectly readback the level as FL370. Neither controller noticed the incorrect readback of the level. The Melbourne sector flight progress strip for the B747 indicated the aircraft was at FL350.

The team leader asked the crew of the B747 if they would be requesting climb to FL370. The crew replied that they would shortly like to climb to the higher level. The team leader instructed the crew of the B747 to climb to FL370 with a requirement to reach that level by PAVKO. The crew reported to the team leader when the aircraft left FL350 on climb to FL370. Normally, an aircraft's change of level is co-ordinated with the next air traffic control agency. The team leader, however, thought he had previously co-ordinated the higher level with the Melbourne sector controller and consequently did not conduct any further co-ordination.

The team leader instructed the crew of the B747 to contact the Melbourne sector controller at PAVKO. When the aircraft reached PAVKO the crew of the B747 reported their position and level of FL370 to the Melbourne sector controller. The Melbourne sector controller had expected the aircraft to report at FL350. There had been an error in co-ordination.

ANALYSIS

The team leader may have relaxed after completing the busiest part of the shift. Additionally, the timing of the incident, the time spent at the position overall, the possible higher level of awareness required for the check and his minor cold, probably combined to the extent that his ability to concentrate adequately on the task was impaired to some degree.

The Melbourne controller may have had an expectation of the B747 being at FL370 due to previous experience and the fact that it is a standard level for aircraft flying a south-easterly route.

The relationship between the body's circadian rhythm and performance is well known. In this incident, the fact that both controllers were working during the early morning and were also approximately halfway through their shifts would probably account for their lack of concentration and the consequent mishandling of the co-ordination.

The team leaders mind-set relating to his intention to approve the crew of the B747 to climb to FL370 would have pre-disposed him to hearing what he expected to hear from the Melbourne controller. This is despite the fact that the team leader co-ordinated the correct level at the time.

SIGNIFICANT FACTORS

1. The team leader had been continuously operating the position for approximately four hours.

2. The incident occurred at a time of the day when errors in human performance are more likely.

The pilot of the Piper PA31 had submitted details for an IFR flight from Lord Howe Island to Sydney via MAGOO and CHEZA at 9,000 ft, estimating CHEZA (60 NM from Sydney on the 084 radial), at 1835. At 1825 the pilot called Brisbane Centre for a clearance and was instructed to squawk transponder code 2350. The aircraft was identified at 50 NM from Sydney, on the 059 radial. This placed the aircraft some 22 NM right of track, within controlled airspace, and in potential conflict with an outbound Boeing 747.

The pilot of the PA31 later reported that he had been initially tracking on a bearing from the Lord Howe Island NDB. However, at the time of the incident he was unable to receive any Sydney radio navigation aids, and was navigating on time intervals and dead reckoning. The PA31 was squawking transponder code 2000 prior to calling Brisbane Centre. The crew of the B747 did not receive any Traffic Alert and Collision Avoidance System (TCAS) warning. Brisbane radar did not record any transponder returns from the PA31 prior to the aircraft squawking code 2350.

On arrival at Crocker Island, during the prelanding checks, the left main landing gear would not lock down. The pilot diverted to Darwin where emergency services were available. He performed the emergency landing gear extension drill, but the left main landing gear was still not indicating down and locked. The pilot flew past the tower for a visual inspection of the landing gear by the tower controller who advised that the landing gear "appeared normal". When emergency services were in place, the pilot landed. As the aircraft slowed on the landing roll, the left main gear collapsed.

Subsequently engineers discovered that the left side brace centre bushing had seized on its bolt thereby preventing the left main landing gear leg from locking down. The operator's chief engineer has formally advised the Civil Aviation Safety Authority of the mechanical fault.

The pilot reported he took a number of tourism industry passengers on a familiarisation flight over a proposed tourist route between Jandakot and Cervantes. He was on the return flight to Jandakot, with his second group of passengers on board, when he was forced to land the aircraft in a paddock due to fuel exhaustion.

The pilot had accumulated a lot of flying hours, predominately in helicopters, but had limited twin-engine, fixed-wing aircraft experience. He had recently completed an endorsement onto the aircraft type and had flown a total of 7 hours in the aircraft at the time of the forced landing. This included the 5 hours flown during the familiarisation flights.

On the evening prior to the occurrence, the pilot had filled the fuel tanks in preparation for the familiarisation flights. Before departing Jandakot on the first leg, he had drained 40 L out of the fuel tanks due to weight restrictions. He was not able to visually check the contents once he had drained the fuel and did not note the level before he started the drain. He paid little attention to the fuel gauges enroute as he normally monitored fuel contents by using fuel flow and elapsed time.

During the return flight, the pilot elected to land at Cunderdin to correct a fuel imbalance which had appeared after he added 200 litres of fuel at Cervantes. He used a bucket and hose to transfer fuel between tanks. He reported that he was not aware of how fuel could be cross fed between tanks whilst airborne.

The pilot became concerned about the state of the fuel contents enroute to Jandakot. He was convinced there was sufficient to continue to his destination, which was, by then, the closest airfield. The aircraft was less than 3 km south of Jandakot when the engines stopped.

Calculations indicate that a total of 620 L had been added to the aircraft before and during the flights. At the reported fuel flow of 94 L/hour a total flight time of 6 hours 35 minutes should have been available. The engines stopped after 5 hours, leaving 150 L unaccounted for. The pilot reported there had been recent instances of fuel theft from the Jandakot apron. As he had refuelled the aircraft the evening before the flights, he suspected the missing fuel had been stolen during the night.

The aircraft was engaged in low-level survey operations over an area of trees in the hills to the east of Perth. The pilot saw a pair of wedge-tail eagles and, despite evasive action, hit one of them. The aircraft sustained some damage which did not prevent the pilot safely tracking to and landing at Jandakot.

The eagle had hit the left wing and caused compression of the leading edge outboard of the left engine.

FACTUAL INFORMATION

The crew of a B737, en route from Perth to Melbourne, requested an arrival on runway 34 after receiving the automatic terminal information service (ATIS) information 'W', which indicated that runway 27 was available for arrivals and runway 34 was available for departures. During the period between the crew receiving the ATIS and requesting runway 34, the aerodrome information changed. The latest ATIS information 'V', which the crew copied, indicated that Melbourne aerodrome was operating on runway 27 for departures and runway 16 for arrivals. The crew was advised that runway 34 was not available, due to the operations on runway 16, and was assigned a standard arrival route (STAR) clearance and runway 16. The crew did not hear the assigned runway because of radio interference and requested confirmation from the sector controller that the runway was 27. The sector controller replied that runway 27 was the assigned runway. The sector controller annotated runway 27 on the flight progress strip for the aircraft. The crews of subsequent aircraft were assigned runway 16 by the sector controller.

The crew of the B737 had not advised the sector controller of the code and receipt of the ATIS, nor had the controller verified that the crew had received the latest ATIS.

When the non-duty runway was assigned, the controller was required to annotate the "ops data" line of the aircraft's label on the radar display with the assigned runway. The "ops data" line for the B737 was not annotated with runway 27. Once the runway and the arrival clearance had been issued by the sector controller, there were no further checks to confirm the aircraft's arrival clearance or assigned runway.

The crew had previously requested track shortening and thought that the sector controller was actioning this request by assigning a runway which required fewer track miles to run to a landing. The crew transferred to approach control and continued to track in accordance with the cleared route. Overhead Essendon aerodrome, the crew continued to track eastwards for a left base to runway 27. The approach controller was expecting the B737 to turn left, to the north, for a left base to runway 16. The approach controller cancelled the standard arrival route and radar vectored the B737 for runway 16. As the B737 approached the centreline of runway 27, the crew requested from the controller the runway to which the aircraft was being radar vectored. The approach controller advised them that the vectors were for runway 16. The aircraft landed on runway 16. There was no breakdown of separation.

ANALYSIS

Initially, the sector controller issued the correct STAR and runway to the crew of the B737. However, when the crew queried the assigned runway, the controller replied with the incorrect runway and then annotated the flight progress strip with the wrongly assigned runway. The reason for the controller assigning the incorrect runway and not amending the "ops data" line of the label could not be determined.

The crew of the B737 did receive the latest ATIS but believed that the sector controller was providing them with their previously requested track shortening by assigning them runway 27. Consequently, they did not query the runway assignment with the Approach controller.

SIGNIFICANT FACTORS

1. The controller did not confirm that the crew of the B737 had received the latest ATIS.

2. The sector controller did not confirm the arrival runway, as indicated in the latest ATIS, when queried by the crew.

3. The sector controller did not amend the "ops data" line of the B737's label on the radar display with the assignment of the non-duty runway.