During pilot training, while practicing hovering techniques, the helicopter incurred a hard landing. Damage to the helicopter consisted of bending of the skid tubes. There were no injuries to the pilot. Although the pilot reported fluctuation of the engine RPM and engine roughness, a subsequent test run of the helicopter engine following removal to a test stand revealed no discrepancies. The reported engine fluctuations could not be duplicated.

When the Beech 1900 entered the Kempsey circuit area on approach to landing, the landing gear relay circuit breaker tripped during the landing gear extension. The tripped circuit breaker indicated an unsafe landing gear state. The gear unsafe indication in the Beech 1900 resides flush on the landing gear selector handle in the form of a red light in the shape of a tyre. 

As the Captain selected landing gear down, the gear selector handle cycled through the transit position for a microsecond before the circuit breaker popped and the unsafe red light remained illuminated. The Captain then entered a holding pattern of orbits above the airfield in VMC at 1500 ft AGL while the First Officer initially attended to the landing gear problem. During the holding pattern, the crew consulted the abnormal checklist but elected not to manually extend the landing gear at Kempsey. The crew made a decision to divert to Williamtown where better emergency facilities were made available. 

On arrival at Williamtown, the crew extended the landing gear manually and received 3 green lights to indicate that the gear was fully deployed and functioning correctly. The aircraft landed without further incident. The aircraft Captain and First Officer demonstrated optimum crew co-ordination and decision-making. The aircraft's landing gear and wiring system was inspected and found to be without fault. The aircraft landing gear was further tested on jacks and cycled without fault. 

As a pre-cautionary measure, the landing gear pump relay, actuator lock switches, selector handle, and time delay printed circuit board were replaced. The extension of the aircraft's landing gear was subsequently and successfully flight tested at varying airspeeds and attitude combinations. The aircraft was then returned to service.

The Tower controller observed some smoke emanating from VH-XLA on departure from runway 16R. The Tower controller informed the pilot of the smoke and consequently, the pilot conducted a precautionary circuit and landing without further incident. 

The engine continued to deliver full power and there were no abnormal engine indications from the cockpit engine instruments. A full emergency was declared and the aerodrome was closed. The emergency co-ordination was hampered by problems with the common crash call (CCC) line between the Tower and the Terminal Operations Controller (TOC). After an uneventful landing, XLA taxied back to the terminal area under an aerodrome fire services escort. The pilot shutdown the aircraft and there was no sign of fire or damage to the left engine. 

A replacement aircraft was sent to Sydney to retrieve the six passengers. A post-flight engineering inspection of the left engine revealed a partially blocked fuel injector nozzle and a default overly rich fuel mixture. During the ground run, a minor puff of black smoke emanated from the left engine at full power. This is not an uncommon consequence of a slightly rich mixture. A company LAME cleaned the fuel injector nozzle. As a further pre-cautionary measure, the fuel control unit was also changed. The left engine operated normally after these items had been actioned. This occurrence also revealed that the CCC to the TOC did not function which delayed the aircraft pre-crash co-ordination. 

The TOC end of the CCC is the responsibility of the airport operator. The circuit commissioning was a 4 wire system at the airport operator's request. The other subscribers to the CCC had complied with this 4 wire circuit system. A telecommunications company was then sub-contracted to perform maintenance on this line for the airport operator. The telecommunications company had then altered the line circuit arrangement to a 2 wire system without apparently informing or co-ordinating this change with the airport operator and Airservices. The new 2 wire system was found to be incompatible with the Airservices 4 wire system. This lack of inter-agency co-ordination has resulted in an inability to efficiently co-ordinate relevant pre-crash taskings in a timely manner. 

As a result of this occurrence, this problem has been resolved. Airservices has modified its' end of the line to a 2 wire system. The airport operator and Airservices now use fully compatible 2 wire circuit systems to communicate between the Tower and the TOC. This emergency communications system has been tested and is now fully functional.

A Boeing 737 was cleared for take-off from runway 23 but was instructed to stop by the Tower controller because a Piper Seminole had inadvertently infringed the upwind end of runway 23 at 1000 ft AGL. The 737 had come to rest at the runway 12/23 intersection. During this sequence of events, a Saab 340 was on final for runway 12 and was instructed by the Tower controller to go around because the 737 was occupying the runway 12/23 intersection.

The Seminole had been cleared by the Tower controller to track for a left base runway 23. The pilot of the Seminole had inadvertently tracked for a right base runway 23 which brought the aircraft into potential conflict with the projected take-off profile of the 737. There was no breakdown in separation. When the Seminole pilot was instructed to turn inland, he thought that he was required to turn inland from the coast and then continue to track North across the extended runway 23 centreline to then join a right base for runway 23. The pilot kept thinking that he was following his clearance despite some anomalies in the instructions being issued to other aircraft such as the 737.

These cues elicited some concern by the Seminole pilot but the pilot did not take further action to clarify the significance of these cues. The pilot of the Seminole was instructed to track for a left hand circuit for runway 23 prior to infringing the extended runway 23 centreline. It is plausible that the pilot had regressed or been captured by his former more frequent habits (glider towing, general flying, and gliding) which required right hand circuits off runway 23 at Gawler airfield. The pilot's default mental model was right hand circuits off a runway 23 configuration. This strong habit intrusion, that is, the unintended activation of the strongest or most contextually frequent action schema most probably contributed to this occurrence.

After re-fuelling the aircraft (VH-ABQ), the pilot experienced significant difficulty with the engine start. The pilot reported that he attempted a hot start which generally requires a large input of initial throttle.

When the engine eventually started, the sudden increase in power exceeded the light braking pressures being applied at the time. The aircraft lurched forward and impacted a vacant, stationary aircraft (VH-DGE) near the fuel bowser before the pilot could retard the throttle and take evasive action. When control of the aircraft was established, the pilot steered clear of the other aircraft and shut down the engine. Both aircraft suffered some minor damage. The pilot of ABQ had no experience in hot starting the aircraft and did not refer to a formal checklist to assist such a start. It appears probable that the pilot did not engage the parking brake fully and/or apply adequate foot pressure to the brakes residing above the rudder pedals.

The pilot did not expect the aircraft to move so quickly, and he was unable to retard the throttle and fully brake prior to impact with DGE. ABQ sustained some damage to the spinner and one propeller blade which had suffered a half inch cut about 6 inches in from the blade tip. DGE had sustained damage to the left hand aft section of the fuselage behind the aft passenger compartment. In particular, this section of the fuselage had been torn by ABQ's propeller which produced a superficial hole of 15 inch diameter in DGE's fuselage skin. In addition, a half inch piece of flap was missing from the left hand side of DGE.

VH-EUX was conducting a normal approach to runway 22. The pilot positioned the aircraft on final approach with 2 stages of flap and trimmed for 70 knots with power on. The pilot selected 3 stages of flap (40 degrees in Cessna 182S) when he descended through 200 to 150 feet AGL. The pilot reported that all indications appeared to be normal until the aircraft entered the flare prior to touchdown. The pilot reported that the aircraft would not round out. In particular, the pilot stated that he pulled the control yoke fully aft to obtain maximum elevator deflection to pitch the nose up during the attempted flare. The pilot was unable to pull the aircraft nose up sufficiently to prevent the nose wheel from impacting the runway.

During the touchdown sequence, the aircraft bounced 4 times. During the first impact, the aircraft nose wheel and right-hand main wheel had impacted the runway first. The pilot then applied power to raise the nose but during this sequence the aircraft impacted the runway heavily again, further damaging the nose wheel. The pilot was then committed to the landing and allowed the aircraft to bounce another two times after which the aircraft came to rest. The aircraft had suffered considerable damage to the nose wheel, the propeller, and the engine bay. The pilot and passengers were uninjured.

The pilot reported that the nose wheel oleo was completely deflated, and the nose wheel directional steering mechanism was damaged. The propeller was bent inwards, and one blade could freely move about the propeller hub. The engine had been displaced about 6 inches upwards during impact. In addition, the right-hand wing strut had transferred the force of the impact to the wing surface which indicated some skin distortion. The engine cowling skin was also deformed.

The Chief Flying Instructor (CFI) of the organisation that hired the aircraft to the pilot stated that the engine firewall was buckled, and the propeller was bent inwards at about 90 degrees 6 inches in from the blade tips. In addition, there was about 5 inches of control cable slack due to the buckling of the floor and the firewall damage. The CFI estimated that the control cables probably suffered this damage during the first impact which would have limited the pilots ability to obtain reasonable control of the elevator during subsequent impacts. The nose wheel struts were bent and pushed into the firewall. There was also a crease in the roof line where the wings join the fuselage. The right main wheel was also damaged.

The pilot had accrued a total flight time of 80 hours of which 26 hours were as pilot-in-command. The Chief Flying Instructor (CFI) considered the pilot as quite proficient or above average but the pilot may have exceeded his ability on this occasion. The pilot had accrued a total of 2.4 hours flight time in EUX prior to the accident flight. The pilot had obtained 3 advanced aircraft type endorsements but had only accrued 10 hours pilot-in-command in a Piper Arrow. The pilot had not consolidated on a Cessna 182S before undertaking additional endorsements.

The weather at the time of the accident was Special VFR. At the time of the occurrence the pilot reported that the cloud ceiling was between 900 to 1200 feet AGL with a 4-5 KM visibility with Nimbostratus in the area. The pilot said that the ATIS had reported a ceiling of 800 feet. Virga had been noted in the vicinity of the airfield and wind shear may have been a possible contributing factor in this occurrence. The pilot noticed rain on the southern boundary of the airfield when he was on final approach for runway 22. The pilot also reported moderate turbulence throughout the flight. Furthermore, the pilot said that the wind was almost a direct headwind for runway 22 at about 25 knots.

The CFI confirmed that there was moderate turbulence in the area. The CFI thought that the pilot may have experienced some wind shear or a wind gust coupled with a high sink rate when the pilot selected full flap at about 200 ft AGL on finals. The pilot's relatively low total time and, in particular, the low experience on type may have contributed to the current accident.

The company will be ensuring that all pilots will be required to accrue 10 hours pilot-in-command on each advanced aircraft type before being permitted to obtain additional endorsements. In addition, the accident pilot has been thoroughly de-briefed by the CFI.

History of Flight

The Kawasaki KH-4 helicopter was engaged in aerial work, spraying larvicide to control mosquitoes at Lake Joondalup in Perth's northern suburbs. The crew consisted of the pilot and an employee of the local city council who was directing the pilot on where to spray. The city council employee occupied the right passenger seat.

The spray runs were being conducted at an altitude of about 30 ft to prevent the pesticide from drifting excessively. The runs started at the east side of the lake, track crawling towards the west. The tracks of each run were orientated approximately north/south, aligned with the shoreline. The pilot reported that turbulence made the helicopter progressively more difficult to control in maintaining speed and height the closer the tracks came to the western side of the lake.

The helicopter had conducted three spray runs during the previous hour without incident. The fourth and final planned run was to cover the western shore area of the lake. While the helicopter was conducting a right procedure turn to track into north, it descended and hit the water. The helicopter came to rest in shallow water almost upright and slightly nose-up. It later rolled onto its right side. The pilot exited the helicopter unimpeded and the passenger released herself from her lap belt. She chose to stay in the helicopter until medical help arrived because she was concerned that she may have sustained a back injury.

Terrain

Lake Joondalup was oriented north-north-west and located in a small valley approximately 5.4 km east of the coast. High ground to the west of the accident site rose to a height of 70 m within 700 m. The ground to the east was more undulating, rising to a height of 100 m within 3 km. To the north-west of the lake were several small saddles. The high ground immediately to the west was a built-up area of residential housing and along the shore were trees to a height of about 6 to 10 m.

Weather

The weather at the time included 3 octas of cumulus cloud at 3,500 ft and 5 octas of strato-cumulus cloud at 4,500 ft. The temperature was 18 degrees Celcius. The wind at Perth airport, 25 km south-east of the accident site, was north-westerly at 14 kts gusting to 21 kts. The wind recording at Ocean Reef, the closest Bureau of Meteorology (BoM) facility to the accident site, was north-westerly at about 10 kts gusting to 13 kts. The Ocean Reef BoM facility was 6 km west of the accident site.

Witnesses at the site described the wind as being north-westerly and blustery with intermittent strong wind gusts.

An assessment of the terrain and wind conditions conducted by the BoM concluded that due to the trees and steep slope to the west of the lake, the wind flow over the area could have been disturbed and that, as a result, turbulence may have developed at the accident site. The BoM reported, however, that the degree of turbulence could not be determined due to the lack of recorded or observational data.

The investigation was on-site within 30 minutes of the accident. The wind was noted as being north-westerly at about 10 kts and gusting to an estimated 20 kts.

Personnel Information

The pilot had a total flying experience of about 724 hours, including 640 hours gained on the Bell 47/KH-4 helicopter types. Although the pilot had completed low-flying training and had acquired about 60 hours in low level operations including survey work, he had no experience in agricultural flying. He had completed a mosquito spraying operation without problems about 8 months prior to the accident. The operator reported that the pilot had conducted most of his low flying operations in relatively benign wind conditions. The pilot complied with the experience requirements under the exemption granted by the Civil Aviation Safety Authority (CASA) for the operator to conduct this particular type of work.

Helicopter Information

The helicopter was a Kawasaki KH-4 which at the time of the accident was within all-up-weight and centre-of-gravity limitations. The KH-4 cockpit/cabin was configured with a centre forward seat that was occupied by the pilot. Three passenger seats were located at the rear of the cabin, just aft of the pilot's seat. Two hoppers, one mounted on each side of the helicopter, were fitted for the disbursement of the dry granulated pesticide. The pilot reported that he was using a power setting of about 32 inches (Hg) Manifold Air Pressure (MAP) to maintain 30 kts groundspeed downwind during the wind gusts and about 25 inches to maintain a similar speed when flying into wind. The take-off (2 minutes) power limit was approximately 33 inches and maximum continuous power was about 28 inches. The maximum power permitted was 36 inches MAP. Flight manual data indicated that the helicopter should have been capable of achieving a rate of climb of nearly 1,000 ft per minute using take-off power at 39 kts.

Turbulence

As wind blows around and against obstacles such as trees, fences and buildings, the smooth flow breaks into a series of irregular, twisting, whirling eddies. These eddies are produced by mechanical turbulence and may rotate about axes in any direction. Mechanical turbulence tends to be lower over relatively smooth ground. The area upwind of the accident site was not smooth due to the trees.

Stronger winds usually produce more and larger eddies, and therefore more turbulence. Eddies could produce downdraughts that would cause a helicopter to lose height. In response, a pilot would need to increase the collective pitch to maintain the helicopter's height above the ground. Turbulence may also adversely affect the aerodynamic efficiency of the helicopter's main rotor blades, reducing the lift being produced by the main rotor system. As a consequence, flying in areas of turbulence usually requires more power to maintain a helicopter's height above the ground.

The adverse effect of turbulence may also be magnified if the helicopter is manoeuvring because the lift being generated by the main rotor system is being tilted away from the vertical. Therefore, only a percentage of the lift being produced by the main rotor is being used to counteract the effect of turbulence.

Flight profile

The pilot reported that he had completed a south-orientated track of the final run and had planned the right procedure turn to roll out heading approximately north. The procedure turn involved turning the helicopter to the left before commencing a right turn. This technique reduced the spacing between tracks. The pilot reported that while the helicopter was in the climbing banked turn to the left, he had flown it to a height of about 50 ft. Once he was sure of maintaining a suitable distance from the west bank of the lake, he commenced the right turn to align with the northerly track. He reported that during the turn to the right, he felt the helicopter begin to sink, so he lowered the nose to accelerate and continued the turn into wind. He also reported that at the time the wind was gusting. The pilot further reported that he felt the helicopter skidding in the turn as it descended below the tree height and he raised the collective and introduced power to arrest its rate of descent. However, the helicopter continued to sink and, realising that he would not be able to complete the turn into wind, he began rolling the helicopter to a wings-level attitude. The observer reported that she thought that the helicopter was "banked right over" and that during the turn, she could feel herself being pushed into her seat. She thought the bank angle was more than she had previously experienced during the morning. The pilot reported that he thought that the bank angle did not exceed 30 degrees.

The pilot reported that he continued raising the collective and introducing power. He reported that he did not over-pitch the main rotor and main rotor RPM remained within limits until the helicopter hit the water. When the helicopter skids hit the water, the helicopter spun through about 180 degrees and came to an abrupt stop. When all motion stopped, the pilot was still seated and restrained by his four-point harness. The observer reported that she thought that she had been pushed against the cabin roof during the impact although she was still firmly restrained by the lap harness after all motion had stopped.

Wreckage Information

The helicopter had come to rest approximately 50 m from the lake's western shore and about 550 m south-south-west of Lake Island. Damage to the main rotor system was consistent with the blades hitting the water under power. Witnesses reported hearing the engine operating immediately before the helicopter hit the water. No pre-existing mechanical fault in the helicopter was found.

The helicopter was being operated in accordance with operator's operations manual and the exemption granted by CASA. Although the pilot was qualified in accordance with requirements in the operations manual, he had no flying training in agricultural operations and was relatively inexperienced in low-level flying operations in adverse wind conditions. There appeared to be no pre-existing mechanical fault that contributed the accident.

During the three spray runs prior to the accident, the helicopter had been positioned towards the eastern side of the lake. The pilot had been conducting the runs approximately north/south and paralleling the shoreline, using the procedure-turn technique to reposition the helicopter for each run. The spray runs were being conducted at a height of about 30 ft with a climb to about 50 ft during the procedure turns. While the helicopter was experiencing some turbulence on the eastern side of the lake, the pilot noted that the turbulence was becoming more pronounced as he worked the helicopter westward. The lower level of turbulence experienced on the eastern side of the lake was consistent with mechanical turbulence dissipating over the smooth open water. In benign wind and turbulence conditions, the reported power margin would normally have been adequate for the task.

While the recorded wind conditions at the nearby Ocean Reef BoM station were quite benign, reports from the accident site indicated that the wind was blustery, and the strength of the gusts appeared to be significantly in excess of those being recorded at Ocean Reef. The lake's north-north-westerly orientation and high terrain to the west possibly increased the wind strength in the local area. The built-up area and vegetation along its western shore possibly induced wind eddies and considerably turbulent conditions near the lake's western shore.

The increasing level of turbulence being encountered by the pilot should have served to indicate that caution was required. Despite the increasing turbulence the pilot did not consider flying the helicopter higher above the water to provide a greater margin for regaining height should the helicopter be affected by the turbulent conditions. Rather, the pilot appeared focused on positioning the helicopter to ensure the spray coverage and to maintain a safe distance from the shoreline and trees. When the pilot banked the helicopter to the right, the evidence was consistent with it entering an area of strong turbulence, which caused the helicopter to unexpectedly descend towards the water. Although the reported power margin would normally have been adequate to effect a recovery in benign conditions, due to the lack of recorded information, the investigation could not determine if the power margin was adequate to overcome the conditions encountered by the helicopter at the time. Also, the pilot may not have used full power to recover from the descent. By the time the pilot realised that the helicopter was descending at an excessively high rate, there was insufficient height available for him to effect a recovery before the helicopter hit the water.

The helicopter's manoeuvring at a low height above the water, local weather conditions and the pilot's lack of experience in low-level operations in adverse wind conditions were probably all factors that contributed to the accident.

The helicopter's operator reported that the procedures and experience requirements for conducting low-level operations were being reviewed.

The pilot of a Cessna 182, VH-EWV, while taxiing for departure at Ayers Rock, turned into an unserviceable taxiway in order to conduct engine checks before take-off. The certified air ground radio operator at the aerodrome asked the pilot if his operations were normal, as this was not a normal procedure. The pilot confirmed that his operations were normal. A Cessna 207, VH-UAA, passed the other aircraft on the taxiway, and continued onto the runway. The pilot of UAA broadcast his intentions and started the take-off run. The broadcast was heard by the radio operator, but not by the pilot of EWV, who also broadcast his intentions to enter the active runway. This broadcast was not heard by either the radio operator or the pilot of UAA. As EWV approached the runway, the radio operator instructed the pilot to hold position. The pilot did not hear the instruction, however, on seeing the other aircraft moving toward his position, stopped immediately near the runway strip. The pilot of UAA continued the take-off, passing at high speed and in close proximity to EWV. The role of the certified air ground radio operator was to provide information, not to give instructions, however the radio operator considered his actions to have been appropriate. The investigation found that the pilot of EWV understood the procedures to be used at the aerodrome. However, it was not possible to determine why communications to and from the pilot were not heard.

VH-JZW had conducted two unsuccessful ILS approaches in IMC to Sydney runway 16 left (16L). JZW was being radar vectored for a third ILS attempt when the pilot elected to proceed to Bankstown. The pilot was unable to execute the approaches within the required tolerances for azimuth and glide slope tracking because of a glide slope failure in the cockpit and the geographic disorientation of the pilot.

During the first ILS approach, the pilot established the aircraft on the localiser and initiated a descent at 600ft per minute. The pilot then noticed large fluctuations of the glide slope needle with intermittent fail flag indications on the instrument. The pilot performed a DME/height check which confirmed that the aircraft was high. Consequently, the pilot increased the descent rate and considered a LLZ/DME approach. The pilot estimated that the aircraft was still too high and elected to conduct a missed approach. The Sydney Tower controller reported that JZW crossed the runway 16L threshold at 1000 ft. During the second approach attempt, the Tower controller reported that JZW was established on the localiser at 10 DME. During this sequence, the pilot noticed that the glide slope needle was still fluctuating unpredictably with intermittent fail flag indications.

The pilot then elected to conduct a LLZ/DME approach. The Tower controller observed the aircraft on radar to deviate to the right and then track between the 16L and 16R localisers. When the Tower controller advised the pilot of these deviations, the pilot attempted to track towards the 16L localiser. JZW failed to intercept final and crossed the 16L centreline at 6 nm on a south-easterly heading at 2,000 ft and descending. The Tower controller instructed JZW to execute a missed approach to ensure that JZW avoided an area of high buildings along its projected track. During the second approach sequence, the pilot stated that there were difficulties contacting Sydney Tower and that the DME lock had inadvertently been activated. The pilot elected to conduct a third approach to runway 16 right. The pilot was radar vectored to intercept the localiser but experienced ongoing and excessive glide slope indications coupled with general anxiety and uncertainty about radio communications and the aircraft's DME unit. Consequently, the pilot elected to divert to Bankstown and landed without incident.

The high workload, limited instrument flying experience, and the distractions precipitated by the radio communications difficulties and a failure of the aircraft's glide slope contributed to this incident. A post-flight inspection revealed that the aircraft's glide slope unit was faulty. The glide slope unit was repaired and functioned correctly when the pilot conducted an ILS approach into Sydney two days after the current incident. The operator is considering installing a new ILS unit in the aircraft in addition to providing the company line pilots with a CASA approved PC-based synthetic IFR trainer to help improve pilot instrument flying skills.

The aircraft failed to comply with the Melbourne runway 34 ARBEY 6 STAR tracking instructions at BUNKY. At BUNKY, the aircraft was observed on radar to track to FENTONS HILL instead of tracking to DEERS. The crew, in answer to a query from air traffic control (ATC), confirmed that they were turning at BUNKY but radar indicated that the aircraft failed to execute the turn. 

Consequently, ATC cancelled the STAR clearance and the crew were instructed by the approach controller to turn right onto a heading of 200 degrees. The crew acknowledged this instruction but failed to execute the turn. The crew finally commenced the turn at Fentons Hill some 10nm after the initial STAR transition point (BUNKY) for Melbourne runway 34. 

The aircraft was subsequently radar vectored to land on runway 34. It was undetermined as to why the crew did not turn at BUNKY or fully comply with the controller's subsequent instructions. It appears that the crew probably misidentified FENTONS HILL as BUNKY. There was no breakdown in separation.