While prior information relating to the radar outage was available to the crew of the 737, they did not become aware of the outage until informed by air traffic control during a high workload phase of the inbound flight, when there was little time to assess the information correctly. During the pre-flight departure briefing, the 737 crew did not reconsider or challenge their misunderstanding of the change to the CTA base with each other or the air traffic controller, which lead them to climb the aircraft into CTA without an airways clearance.

The non-availability of radar services below 8,000 ft, together with the forecast weather conditions, low level of CTA base and aircraft performance characteristics warranted greater diligence by the controller to implement tactical separation assurance. The controller relied on the crew of the 737 remaining outside controlled airspace, clear of weather and below the LSALT, as an initial separation strategy with the Dash 8.

While the onus is on a pilot to ensure adequate terrain clearance, the clearance issued to the crew by the controller did not comply with the provisions of MATS. The potential existed for the 737 crew to not meet their responsibilities under CAR 157 and 178 for minimum terrain clearance.

On 6 April 2005, at 1253 Eastern Standard Time, a de Havilland Canada DHC-8-102 (Dash 8) aircraft departed Mackay for Townsville, Qld. The aircraft was being operated under the instrument flight rules (IFR) and was climbing to flight level (FL) 160. At 1254, a Boeing Company 737-800 (737) aircraft departed Proserpine for Brisbane, Qld. The aircraft, with two pilots and a company approved observer, was being operated under the IFR. The crew's intention was to climb the aircraft to 8,000 ft above mean sea level (AMSL) pending a clearance from air traffic control (ATC) to enter controlled airspace (CTA) on climb to the planned FL410.

The airspace in the Proserpine area was classified as class G (non-controlled) airspace from ground level to 4,500 ft and class C (controlled) airspace from 4,500 ft to FL180.

Within class C airspace, air traffic controllers are required to separate IFR aircraft from other IFR aircraft.

Figure 1: Extract from Mackay Terminal Area Chart

At 1256, the sector controller issued the crew of the 737 with a clearance to enter CTA on climb to 5,000 ft to establish the minimum vertical separation standard of 1,000 ft with the Dash 8, prior to conducting a step climb¹. The 737 crew reported they were approaching 6,000 ft and commenced a descent to 5,000 ft.

Recorded data later showed that the 737 reached a maximum altitude of 6,400 ft with a minimum vertical spacing between the two aircraft of 430 ft and it was calculated that the aircraft were approximately 45 NM apart laterally. At 1257, the vertical separation standard of 1,000 ft was established and, at 1300 when the two aircraft were radar identified, they were about 25 NM apart laterally.

At the time of the incident, the radar that normally provided low-level coverage within the area had been temporarily removed from service, restricting coverage to above 8,000 ft. A notice to airmen (NOTAM) had been issued, which detailed the planned outage, the restricted radar coverage, and possible delays in CTA.

The crew of the 737 later reported that they had obtained and read briefing material, including NOTAMs, but did not recall any information relating to the radar outage. They first became aware of the outage at about 9,000 ft during the previous flight on the inbound descent to Proserpine, when they were instructed by the controller that the radar was off and radar services were terminated. At that point, they mistakenly confused the termination of radar services with a change in the base of CTA to 9,000 ft. Prior to departure from Proserpine, the crew briefed and set 8,000 ft as an initial level for climb, believing this level to be outside CTA.

The published minimum sector altitude (MSA)² around Proserpine was 4,500 ft within 10 NM and 5,100 ft within 25 NM. The lowest safe altitude (LSALT) for the departure track of the 737 was 5,500 ft. As a result, the cleared level of 5,000 ft was below the LSALT for the aircraft.

The forecast cloud at Proserpine was scattered at 2,000 ft and broken at 4,000 ft and the 737 crew later reported entering instrument meteorological conditions (IMC) when passing about 2,500 ft on the departure climb.

The Manual of Air Traffic Services (MATS) section 6.1.2.1 specified that clearances issued shall enable the pilot to comply with Civil Aviation Regulations (CAR) 157, relating to minimum heights for aircraft operations. CAR 178 specified that a pilot must not fly an aircraft at a height lower than the published lowest safe altitude, 'and on departure this means the time during which an aircraft is climbing after take-off at a rate that is reasonable under the circumstances'. MATS 6.1.2.5 specified level assignment shall take into account terrain clearance and MATS 6.1.7.1 specified that a pilot may [only] be assigned a level below the LSALT provided that the pilot has reported 'visual' and 'visual' is appended to the clearance.

The air traffic controller later stated that he understood that the responsibility for terrain clearance on departure was a pilot responsibility and there was a published LSALT on the departure track for pilot reference. As he did not expect the aircraft to have to maintain 5,000 ft in the step climb, he did not issue a 'visual' instruction with the level assignment.

MATS 4.1.1.4 provided guidance to controllers relating to tactical separation assurance, which:

'places greater emphasis on traffic planning and conflict avoidance rather than conflict resolution. This is achieved through the proactive application of separation standards to avoid rather than resolve conflicts; planning traffic to guarantee rather than achieve separation; executing the plan so as to guarantee separation; and monitoring the situation to ensure that plan and execution are effective.'

1. Step climb is a procedure used to simultaneously climb aircraft to vertically separated levels.
2. Minimum sector altitude (MSA) and lowest safe altitude (LSALT) are calculated to provide 1000 ft obstacle clearance for IFR flights, and are published on aeronautical charts and in the Aeronautical Information Publication (AIP) for pilot and controller reference.

On 8 March 2005, the Gippsland Aeronautics Pty Ltd GA-8 aircraft, registered VH-FGN, was carrying emergency relief supplies from Muelaboh to Patek in Aceh Province, Indonesia, as part of the Tsunami relief effort. The aircraft occupants comprised the pilot and one passenger.

At about 1326 Eastern Daylight-saving Time on 7 March 2005, the pilot of a Cessna Aircraft Company 310R, registered VH-FIN, took off from runway 30 Right at Tamworth Airport, for Scone, NSW. Approximately 1 minute after becoming airborne, the pilot reported flight control difficulties. At about 1329, the aircraft impacted the ground in a cleared paddock about 7 km west-south-west of the airport. The pilot was fatally injured, and the aircraft was destroyed by the impact forces and post-impact fire.

Examination of the aircraft's mechanical flight control systems, autopilot and electric trim system did not reveal any evidence of pre-impact malfunction. Those results, however, were inconclusive due to the extensive impact and fire damage. A bent hand tool found in the wreckage was not implicated in the development of the accident.

A periodic maintenance inspection carried out in the days before the flight resulted in the rudder trim tab being set at the full right position and possibly aileron and elevator trim tabs being set at non-neutral positions prior to the flight. There were indications that the pilot was rushed and probably overlooked the rudder and aileron trim tab settings prior to take-off. The aircraft flight path reported by witnesses was found to be consistent with the effect of abnormal rudder and/or aileron trim tab settings.

The investigation found that aircraft operating checklists produced by aircraft operators did not always include the autopilot and electric trim procedures located in the supplements of aircraft operating handbooks/flight manuals. At the time of the accident, the training and guidance generally provided to pilots did not emphasise the management of flight control difficulties including autopilot and electric trim related difficulties.

Following the accident, the aircraft operator and the maintenance provider advised that they had reviewed and amended some procedures. The Civil Aviation Safety Authority advised that a Civil Aviation Advisory Publication titled Multi-engine Aeroplane Operations and Training will be issued by July 2007 and that three items have been forwarded to the Safety Promotion Branch for consideration/action.

At 0825 local time on 10 March 2005, a Bell 212 helicopter with three crew and five passengers departed Wallaby landing zone near Moliana, East Timor to conduct an aerial survey of the island. Prior to the flight, the passengers requested that the cabin sliding doors be secured in the open position for better observation. At approximately 0935, while tracking along the coast at 90 KIAS at approximately 800 ft AGL, the flight crew reported that they experienced a bump to the helicopter similar to air turbulence. A subsequent control and instrument check did not reveal any problems. The rear crewmember then informed the pilot in command (PIC) that the right cabin sliding door had fallen off. The PIC elected to conduct a precautionary landing in a nearby field. Following the landing, damage to the right side of the tail boom and horizontal stabilizer was noted and the door recovered for examination.

The Australian Transport Safety Bureau examined the sliding door attachment hardware to determine if there were any pre-existing faults of the components.

Examination of the aircraft and wreckage revealed that the forward roller support of the passenger door had fractured. The part had no specified safe life.

1.1 Assembly information

Two parts were recovered from the forward door assembly, the forward roller support and the mating serrated plate.

The forward roller support (35), illustrated in figure 1, is located inside the passenger compartment of the helicopter and is one of four roller attachments of the passenger door to the upper track. When the door is in the open position, this attachment carries the entire load of the passenger door. Elliptical holes through the support and its attachment to the mating serrated plate (38) via screws (34), allow the door to be located between the upper and lower roller tracks.

Figure 1: Forward Door Support Assembly.

1.2 Visual Examination

1.2.1 Forward Roller Support

The forward roller support was recovered in two sections shown in figure 2 as A and B. The fracture of this part extended through the serrated area of the support, 45mm from the top of section A and intersecting with the elliptical locating holes. The support was painted with a chromate primer and a grey top coat, together approximately 100µm thick.

Figure 2: Section A of the forward roller support (left) and Section B of the forward roller support (right).

The fracture surface revealed striations and ratchet marks, consistent with fatigue failure. Part of the fracture surface of section B, shown in figure 3, reveals ratchet marks occurring at the serrated edge of the support (1) and final fracture at the back edge of the support (2). This is consistent along the entire fracture surface.

Figure 3: Fracture surface of section B, ratchet marks are visible at the serrated edge of the part (1) and the final fracture of the back edge of the part (2).

Iron oxide deposits were also observed on sections A and B. Location of the oxide coincided with the mating surfaces of the forward door assembly and the serrated plate and between the elliptical holes and the locating screws. Close examination of the elliptical holes revealed the paint layer was pleated as shown in (figure 4). The location of these pleats coincided with the positions of locating screws. Further deterioration of the paint layer was also observed in this area, leaving the yellow primer exposed.

Figure 4: Oxide products within the elliptical holes of section B. Note the top coat deterioration and pleating (circled) revealing the chromate primer layer (yellow).

1.2.2 The Serrated Plate

The serrated plate attachment, shown in figure 5, was not painted. Iron Oxide and fretting of the holes were observed, shown in figure 6.
The screws that attached the roller support and serrated plate to the passenger door were not recovered for this investigation.

Figure 5: The serrated plate.

Figure 6: Fretting around holes in the serrated plate. Iron oxide products are also visible.

1.3 Metallographic Examination

A segment of the forward roller support including the fracture surface and serrations was removed from section B. The representative sample was prepared and examined to characterise the materials general microstructure.

The material which exhibited magnetic properties, revealed a microstructure typical of a Precipitation Hardened (PH) Stainless Steel . PH Stainless Steels are often used in the aircraft and aerospace industries due to superior hardness and corrosion resistance.  The martensitic type microstructure revealed by this sample, shown in figure 7, is typical for this material.

Figure 7: Microstructure of the forward roller support material (10X magnification).

Figure 8: The metal (1), primer (2) and top coat layer (3) interfaces (10X magnification).

Vickers hardness tests were carried out using a 20kg load, a total of five tests returned a mean value of 323 HV. These hardness results are typical of PH stainless steels.

FRACTURE CHARACTERISATION

Using light microscopy, the fracture surface of section A revealed the part had failed in fatigue. Crack initiation was identified as occurring on both sides of the right screw hole, circled in figure 9, and more clearly shown in figure 10. Ratchet marks at the serrated edge of the support indicated that crack progression occurred in the direction arrowed in figure 9, and through the thickness of the part. Rapid, unstable fracture characterised by a brighter fracture surface was also observed, shown in figure 11.

Figure 9: Fracture surface of section A. Crack initiation sites are circled and crack propagation directions are indicated with arrows (6X magnification).

Figure 10: Crack initiation sites, section A (6X magnification).

Figure 11: Rapid, unstable fracture surface, section A. Note the brighter appearance of the fracture surface (6X magnification).

Technical Analysis Report No. 22/05

Occurence No. 200501155

Examination of a Failed Forward Door Attachment from a Bell 212 aircraft, registered VH-LHX, on 10 March 2005.

Factual Information

On 4 March 2005, at 1405 Eastern Daylight-saving Time, a Boeing Company 737-86N aircraft, registered VH-VOG, was being operated on a scheduled passenger service from Melbourne to Brisbane. The pilot in command (PIC) reported that during the take-off roll, the aircraft unexpectedly deviated to the right of the runway 27 centreline and the nosewheel felt as though it ‘had been caught in a groove’. The PIC applied left rudder to regain directional control and continued the take-off and flight to Brisbane. The circumstances of this incident were similar to those identified in a previous Australian Transport Safety Bureau (ATSB) investigation, (see investigation report 199703237).

Sequence of events

On 5 March 2005, at about 1240 Western Standard Time, an Avions Pierre Robin R-2160 aircraft, registered VH-OXY, was inbound to Jandakot Airport, WA. The flight was being conducted in the private category and the pilot was the sole occupant of the aircraft.

The pilot recalled that the aircraft was about 2 ½ NM west of the aerodrome and at an altitude of 1,200 ft when the engine suddenly lost power. The pilot was attempting to make an emergency landing on a residential street, when the outboard portion of the right wing collided with a suburban power pole. The aircraft rolled inverted before impacting the ground. The aircraft was substantially damaged. The pilot sustained minor injuries and vacated the aircraft without assistance. There was no spillage of fuel at the accident site and no post-impact fire. The maintenance personnel who attended the accident site inspected the aircraft's fuel tank and found that it did not contain any fuel.

An overhauled engine had just been fitted to the aircraft and the pilot reported that he was carrying out the engine manufacturer's procedure for engine break-in¹. That procedure included that, after reaching cruise altitude, a pilot conducting the recommended 2.5 hours break-in flight should:

• Reduce the engine power setting to 75% maximum rated for the first hour of the flight. Data contained in the engine manufacturer's operator's manual indicated that 75% power was obtained at 2,450 RPM, and that the fuel consumption at that power was about 38 L/hour.
• Alternate the engine power between 65% and 75% during the second hour. The engine manufacturer's operator's manual indicated that 65% power was obtained at 2,350 RPM and resulted in a fuel consumption of about 34 L/hour.
• Operate the engine at 100% power for 30 minutes, provided that the engine and aircraft are performing within the published operating manual specifications. Data extracted from the engine manufacturer's operator's manual indicated that 100% power would be achieved at 2,700 RPM and resulted in a fuel flow of about 53 L/hour.

Based on data contained in the engine manufacturer's operator's manual, it was estimated that the recommended engine break-in flight could have consumed between about 108 and 137 L of fuel.

The pilot reported that, during the engine break-in flight, he operated the aircraft's engine as follows:

• between 2,500 and 2,600 RPM for the first 2 hours of the flight
• at 2,700 RPM for the remainder of the flight before returning to Jandakot. The aircraft engine lost power 2 hours 41 minutes after take-off.

The pilot stated that he used a calibrated dipstick to dip the aircraft's fuel tanks prior to the flight, and that the tanks contained 118 L of fuel. He had expected the aircraft to use 35 L/hr, which was the standard fuel consumption used by the company for flight planning in that aircraft type.

The aircraft was equipped with an annunciator panel that included a warning light to indicate a low fuel quantity. However, black adhesive tape had been stuck over that panel, preventing the pilot's view of the low fuel quantity warning light. Neither the aircraft's owner/operator nor the relevant maintenance organisation could explain why the tape was stuck over the panel.

1. First in-flight run of a newly overhauled engine.

At about 1240 Western Standard Time on 05 March 2005, an Avions Pierre Robin R-2160 aircraft, registered VH-OXY, crashed on a residential street, about 2 ½ NM west of Jandakot Airport, Western Australia.

The pilot reported that he was inbound to Jandakot when the engine suddenly lost power. The outboard portion of the right wing collided with a suburban power pole during the approach for the emergency landing and the aircraft rolled inverted and impacted the ground. The pilot, who was the sole aircraft occupant, sustained minor injuries and vacated without assistance. There was no spillage of fuel at the accident site and no post-impact fire. Personnel at the accident site inspected the aircraft’s fuel tank and observed that it did not contain any fuel.

The aircraft was on its first flight following maintenance, which had included the installation of an overhauled engine. During the flight the pilot completed the procedure for break-in of an overhauled engine. At the time of the accident, the aircraft had been airborne for 2 hours 41 minutes.

The circumstances of the engine failure were consistent with fuel exhaustion. Contributing to the fuel exhaustion were the higher than normal power settings, and therefore fuel consumption, associated with the conduct of the break-in flight.

Although uncertain as to the meaning of 'reverse bay', the flight crew thought the term was used to indicate the method of positioning the aircraft on the bay. Any uncertainty about the reverse manoeuvre should have been resolved by the crew before the aircraft was reversed.

The stop signal used by the marshaller was ambiguous as the arms were repeatedly crossed at chest height and not over the head. The operator's ground handling manuals included information that the use of marshalling bats would minimise the risk of misidentification. The opportunity for any misinterpretation of the stop signal used may have been minimised if marshalling bats had been used in this instance.

The intervention of the off-duty marshaller was timely and appropriate. Had he not taken this action, it is likely that the aircraft would have collided with the terminal building. The crew's uncertainty with parking on a reverse bay, and the marshaller's use of an unfamiliar hand signal combined to create doubt in the minds of the crew as to what the marshaller's intentions were.

On 19 February 2005 at 1310 Eastern Daylight-saving Time, a de Havilland Canada DHC-8-102 aircraft, registered VH-TQR, was being operated on a scheduled regular public transport service from Canberra, ACT, to Sydney, NSW. On arrival at the terminal the crew was given marshalling instructions from ground staff to taxi onto bay 57R and stop. The pilot in command (PIC) then reversed the aircraft until instructed to stop by an off-duty marshaller who had seen that the tail of the aircraft was very near to the Terminal 2 building.

While en route to Sydney, the crew had contacted the operator's movement control officer to request a parking bay and to advise that the weather radar was unserviceable. The crew were advised to expect a 'reverse bay'. The crew discussed the requirement to park on a reverse bay. They were uncertain if the aircraft was to be reversed onto the correct stopping point. There was no discussion about the marshalling signals they would expect to see. The PIC referred to the aircraft's parking bay diagrams (see Appendix A) and was satisfied that the lead in lines painted on the tarmac and the signals of the marshaller would provide sufficient guidance.

After vacating runway 34 left, the crew was advised by the operator to park on bay 57 reverse (57R) so that engineers could repair the weather radar. Bay 57R is located near the southern end of Terminal 2 Pier B (see Figure 1) and required aircraft to park with the nose pointing away from the terminal.

Figure 1: Parking bay 57 (for illustrative purposes only)

The bay is also marked 57A for aircraft parked facing the terminal. Bay 57R was used to park aircraft in conditions of strong westerly winds, or if engineering staff required the nose of the aircraft to be facing away from the terminal building. The bay was commonly referred to by both ground staff and flight crew as 57 reverse or a reverse parking bay.

The PIC taxied the aircraft to Bay 57R, where it was marshalled into position and stopped by the crew when they observed the marshaller cross his arms once at approximately chest height. The position of the aircraft at that stage was correct for Bay 57R. However, the crew were concerned that the aircraft was positioned too close to a vehicle access road marked on the movement area and after briefly discussing between themselves the meaning of the signal used by the marshaller, decided that the instruction was to reverse. The PIC then reversed the aircraft and anticipated that the marshaller would signal them to stop at the correct point. The crew noted that the marshaller was walking toward the aircraft as it reversed, using hand signals which they interpreted as confirmation of the reverse manoeuvre, but which the marshaller intended as a signal to stop.

The marshaller had been told that the aircraft had a problem with the weather radar, which required that the ground power unit (GPU) be positioned away from the aircraft's nose. When the aircraft started to reverse the marshaller thought the crew were also positioning the aircraft away from the GPU.

Three off-duty marshallers were in a lunchroom, adjacent to bay 57R, when the shift supervisor observed the aircraft being marshalled onto the bay. He then saw the aircraft reversing and alerted the other two marshallers in the room to the situation. They observed the aircraft marshaller signal the PIC to stop the aircraft, by crossing his arms repeatedly at chest height. One of the off-duty marshallers ran out onto the tarmac to the aircraft's two o'clock position¹ and signalled the crew to stop by crossing his arms over his head. The tail of the aircraft was estimated by that off-duty marshaller to be within 1 m of the terminal. The shift supervisor also went onto the tarmac and marshalled the aircraft forward to the correct bay 57R stop position.

The on-duty aircraft marshaller had received training on aircraft ground marshalling in accordance with the operator's ramp handling course document. The description for 'stop' in that document was in accordance with the Civil Aviation Safety Authority Civil Aviation Order (CAO) 20.3 Issue 5, Air Service Operations, Marshalling and Parking of Aircraft.

Stop is indicated by the arms to be repeatedly crossed above the head. (the rapidity of the arm movement related to the urgency of the stop, ie. the faster the movement the quicker the stop).

Other documentation used by the operator that included marshalling signals were a Customer Service Ground Handling Manual and a Flight Deck Engineering Manual that both stated:

Arms extended to full length above head in vertical position with bats or wands held steady. Widely accepted signal for use when there is no urgent stop requirement.

Although not in accordance with CAO 20.3, this signal was recognised by ground staff and by flight crew to indicate stop.

All of the manuals reviewed as part of the investigation stated that marshalling bats should be used to minimise the risk of misinterpretation. However, marshalling conducted by the operator during daylight was conducted without the use of marshalling bats.

1. The numbers on a clock are used to describe relative position, where 12 o'clock is directly in front. For example, a person or object observed abeam to the left of an aircraft would be said to be at 9 o'clock.

On 19 February 2005 at 1310 Eastern Daylight-saving Time, a de Havilland Canada DHC-8-102 aircraft, registered VH-TQR, was being operated on a scheduled regular public transport service from Canberra, ACT, to Sydney, NSW. On arrival at the terminal the crew was given marshalling instructions from ground staff to taxi onto bay 57R and stop. The pilot in command (PIC) then reversed the aircraft until instructed to stop by an off-duty marshaller who had seen that the tail of the aircraft was very near to the Terminal 2 building.