The pilots of a Bell 212 helicopter (VH-HHW) and an Aerospatiale AS-350B2 Squirrel helicopter (ZK-HNE) were engaged in aerial filming for a motion picture sequence above the middle of Rees Valley in the Southern Alps of New Zealand.

The pilots were very experienced in aerial filming, and conducted a thorough pre-flight briefing for the "point in space filming sequence". The briefing included flightpaths, airspeed, altitude, emergency actions, abort procedures, clearance distance and weather minima. The location features provided few peripheral visual cues for hovering and judging the rate of closure and distance between the helicopters.

The Squirrel was in a hover facing North-West or upstream towards the mountains at 2,500 ft above ground level (AGL) filming the Bell in a fly-by manoeuvre. The filming sequence required the Bell to descend from 3,500 ft AGL at 70 knots towards the Squirrel passing by the right side of the Squirrel (North-West to South-East) and then continue flying straight ahead. The Australian company Operations Manual (Section D4.1-Still and Motion Photography) required the pilot of the Bell to maintain "normal separation" with another aircraft involved in an aerial filming sequence. This separation was defined by the Chief Pilot as 150 m.

During this manoeuvre, the second run for the day, the main rotor blade of the Bell struck the top of the vertical fin of the Squirrel. The pilot of the Squirrel reported some moderate wake turbulence from the rotor tip vortices of the Bell during this pass but neither pilot realised the helicopters had collided. Consequently, the minor damage was not discovered until the helicopters returned to Queenstown at the end of the day's filming.

Inspection found that the top of the Squirrel's vertical fin had been struck by the Bell's main rotor blade. There were two small dimple indents on the leading edge of the main rotor blade cap and some paint scratching in from the end of one main rotor blade. The first dimple was 146 mm from the blade tip and the second dimple was 57 mm from the blade tip.

The investigation revealed that the "point in space filming sequence" manoeuvre can induce a "rejoin illusion" in pilots that limits their ability to accurately judge closure rates. In particular, the pilot of the Bell may have initially experienced an apparently very slow closure rate on the Squirrel followed by a rapid, difficult to judge, increase in apparent closure rate from approximately 100 m to run. The closure rate of the Bell was approximately 120 ft per second. The rejoin illusion is more marked with higher closure rates and the smaller the aircraft being approached. In addition, the black paint scheme of the Squirrel against the relatively dark background of the terrain may have made it even more difficult for the pilot of the Bell to judge the position of the other helicopter. This poor visual contrast had been discussed in the pre-flight briefing.

In addition, the investigation found that the workload of the Squirrel pilot was very high which may have precluded his ability to detect the impending collision and to call an abort. The Squirrel pilot was the aerial director of the film sequence and was subject to additional airborne communications and the professional pressure required to produce quality direction as well as maintain the helicopter in a 2,500 ft AGL hover in strong winds with limited visual cues. Furthermore, it is possible that the Squirrel pilot may have drifted laterally towards the Bell 212 because it is very difficult to maintain an exact stationary hover at altitude with limited visual references.

The absence of a clear and specific quantitative definition for "normal separation" in the Operations Manual for the Bell 212 (Section D4.1- Still and Motion Photography) represented a latent failure in the operator's procedures. Following this incident, the Operations Manual was amended to clarify the definition of "normal separation". In addition, company pilots involved in New Zealand operations were issued with an Operational Memo that imposed a specific quantitative interpretation of "normal separation".

The operator of the Squirrel amended their procedures to stipulate that camera helicopters in high hovers without nearby visual references were required to maintain a minimum indicated airspeed of 10-15 knots to reduce the possibility of subtle lateral drift. In addition, the operator documented specific lateral clearance limitations between helicopters engaged in aerial filming sequences.

Organisational and regulatory issues that became apparent during the investigation included separation distances between aircraft in close proximity and the definition of formation flying. The Australian Civil Aviation Regulation 163 AA states that aircraft must not be flown in formation unless each of the pilots in command has been approved by the Civil Aviation Safety Authority (CASA) to fly in formation and the formation is pre-arranged between the pilots in command. For the purposes of the regulation, two or more aircraft are considered to be in formation if they are flown in close proximity to each other and they operate as a single aircraft with regard to navigation, position reporting and control. In addition, aircraft are considered to be in formation during join-up and breakaway (CAR 163 AA 5(b)). New Zealand CAR 91.227 has similar provisions.

The New Zealand Civil Aviation Authority (CAA) legislation was the relevant legislation in force at the time of this incident and CAR 91.227 stated that no pilot shall operate an aircraft so close to another aircraft as to create a collision hazard. Formation flight is defined as more than one aircraft which navigate and report as a single aircraft; and are no more than one nautical mile laterally and within 100 ft vertically from the formation leader. The aircraft were flown so close to each other as to create a collision hazard. Close formation flying training and certification may have assisted the pilots to avoid a collision on this occasion. Both CAA and CASA are currently reviewing and developing the safety requirements, advisory material, and acceptable standards for operations where aircraft are flown in close proximity to each other in a commercial operation, such as aerial film making.

The organisational and regulatory issues have been addressed in greater detail in the Civil Aviation Authority of New Zealand Aircraft Accident Report 99/2768.

VH-TJZ was cleared for a rolling take-off from runway 16 right (16R). During the take-off roll at approximately 40 knots IAS, the Tower controller cancelled TJZ's take-off clearance and instructed TJZ to hold position. TJZ was brought to rest abeam taxiway F with light braking. During this sequence of events, VH-EKN was on short final approach to runway 07 when the Tower controller instructed the crew to execute a go-around manoeuvre.

During the climb to cruise altitude, the pilot in command noticed that the co-pilot's head was resting on a side window and that he was not responding. After gaining assistance from cabin crew he found that the pilot had been ill into an airsickness bag. The co-pilot was restrained in his seat and a return to Brisbane was requested. The co-pilot regained and then lost consciousness a number of times during the arrival. Weather conditions were suitable for a visual approach, and an uneventful landing was made.

The pilot was examined by a company doctor, and although no obvious reason for his illness was found, a viral infection was suspected. The co-pilot had been restrained in his seat for his own safety during the landing and his head had been allowed to tilt forward. The doctor suggested that crews be warned that in this type of situation, if the sick crew member's head is not held back, there is a possibility of suffocation due to an obstructed airway.

The aircraft was on the take-off roll, commencing rotation at approximately 113 knots indicated airspeed when the crew noted a flight of possibly three ducks off the left-hand wing. Shortly after the crew reported that the number one engine suddenly experienced a destructive failure and shutdown with no cockpit indication. The crew continued the take-off and retracted the main landing gear.

They reported that the gear cycled very slowly and that they were apprehensive about a possible bird strike to the gear as well as the engine. Because of this concern they then proceeded to a diversion airport where emergency services were available. Enroute, they reported no problems in continuing the flight on one engine. At the diversion airport they extended the main landing gear and proceeded to land without further incident. During post occurrence examination, outward penetration shrapnel damage was evident on the low-pressure compressor case which indicated an uncontained failure of the case. The damage appeared to be the result of the shedding of portions of the low-pressure compressor fan blades. Additionally, secondary damage caused by shrapnel penetration of the low-pressure compressor case resulted in several areas of outward denting of the number one engine cowl.

The number one engine cowling contained the penetration. There was no significant damage to the fuselage of the aircraft. The JT-15D-4 incorporates an emergency shutoff feature which prevents possible low-pressure turbine overspeed in the event of a low-pressure turbine decouple. Metered fuel to the fuel manifolds is automatically cut off to prevent possible overspeed of the low-pressure turbine assembly. It appears that in this occurrence, the axial displacement of the low-pressure compressor fan during the bird ingestion event had activated the emergency shut off feature. A bird feather recovered internally from the damaged aircraft number one engine was sent for examination. An ornithologist reported that analysis of the feather indicated the feather was that of an Australian Wood Duck, with an average full-grown weight of 800 to 815 grams.

Confirmation of the exact number of birds ingested into the engine during the occurrence could not be confirmed, therefore, compliance to published foreign objects ingestion requirements could not be conclusively established.

During a flight controls check prior to take-off, the aircraft experienced an apparent binding of the elevator control system at a location just forward of the aft stop. The flight was aborted and the aircraft returned to the gate for further investigation. Maintenance personnel carried out further investigation into the control system, to include a complete operational check of the elevator control system. The subsequent checks completed both powered and unpowered revealed none of the ratcheting and binding reported by the flight crew. After a thorough check the aircraft was returned to service.

The identification and planned level (FL290) of the aircraft was coordinated with the Melbourne Sector 12 controller. The aircraft was observed on radar to maintain FL250. The amended level was not coordinated with sector 12. There was no infringement of separation standards. 

An investigation by Airservices Australia found:

1. that the sector did not have specific procedures to ensure that controllers on adjacent sectors were notified when sector 12 opened/closed,

2. the Hume sector controller did not coordinate the change of level with the sector 12 controller,

3. a console display notifying active sectors had not been updated, and

4. that the display did not provide an indication of combined sectors. Consequently, there had been some confusion in relation to the required coordination between sectors. The investigation is continuing.

While cruising at 8,000 ft, enroute from Brisbane to Maryborough, the crew of the Shorts 360 aircraft heard a loud bang emanate from the left engine, followed by an increase in the engine's inter-turbine temperature indication. The crew shut-down the engine in accordance with company operating procedures and diverted for a landing at Maryoochydore. Following an initial inspection, the operator removed the engine and forwarded it to the manufacturer for an investigation and report. The manufacturer found that the engine's number 1 bearing had failed. The bearing balls and races exibited "spalling", and fatigue fracturing of the bearing roller cage was evident. The investigation report concluded that due to the severe secondary damage to the bearing assembly, the reason for the failure of the bearing could not be determined.

The aircraft was enroute to Mount Buller on a medivac priority flight after having departed Essendon. During climb out to cruise level, the aircraft experienced a caution advisory indicating low oil pressure of the number two engine. The crew initiated emergency procedures and completed an uneventful precautionary landing near Thomastown.

Further investigation revealed oil leakage in the area of the number two engine deck. An engine magnetic particle detector receptacle was found loose and backing out, because of a failed lockwire, thereby causing the oil leakage. The engine number two and three modules were replaced as a precaution and the aircraft returned to service.

The crew had been issued a runway 34R MARUB2 SID with a requirement to maintain 5,000 ft and had confirmed this altitude on contact with Departures North. The aircraft was then observed on radar to climb above the assigned altitude. The controller confirmed the altitude requirement and passed traffic information on a crossing A320 at 6,000 ft.

The B737 crew immediately descended from 5,400 ft to 5,000 ft. Concurrently the crew of the A320 responded to a TCAS Resolution Advisory and climbed from 6,000 ft to 6,700 ft. A plot of the recorded radar data showed that the B737 had levelled at 5,400 ft and that the two aircraft had come within 600 ft of one another. The required standard was 1,000 ft and, therefore, an infringement of separation standards had occurred. The company operating the B737 conducted an investigation into the circumstances surrounding this incident and a copy of their report was duly lodged with the Bureau.

Their investigation found that a captain under training was flying the aircraft. A training captain occupied the right crew seat and performed the crew functions of the pilot not flying. The captain under training was hand-flying the aircraft at the time of the incident. Although he had correctly set the assigned altitude of 5,000 ft in the window of the Mode Control Panel, the Flight Director (FD) did not capture the 5,000 ft level-off altitude and, despite the training captain having alerted him to the approaching assigned altitude, he had allowed the aircraft to climb above the assigned 5,000 ft altitude. An intermittent fault in the altitude selection function of the FD had been detected a few days earlier but because the problem was not thought to be an aberrant operation, it was not reported. After this occurrence the problem was reported and a few days later manifested itself in a 'hard' failure.

The Mode Control Panel of the Flight Management System was subsequently replaced. The investigation concluded that the slow response of the captain under training had allowed the aircraft to exceed the assigned altitude. The company's Standard Operating Procedures were found to be adequate and, despite this event, did not require amendment. However, a recommendation was made that training captains require pilots under training to use greater levels of automation in busy flight phases in order to enhance their monitoring role.

No text.