Summary

Tauranga Chief arrived at Sydney from Port Kembla on 17 January 2003 on its normal liner route. It had sailed from Port Kembla the previous evening and arrived at the Sydney pilot boarding ground on schedule at 0300 local time. The pilot boarded as planned and the ship continued inwards toward the booked berth at White Bay container terminal.

When the ship came to an intended course alteration position in the harbour, east of Bradleys Head, the pilot initiated the turn to starboard to round the headland. He firstly ordered 5 starboard rudder and, when the ship did not respond quickly enough, he increased the order to starboard 10. The rate of swing increased markedly and so the pilot ordered port 20 to slow the swing. The seaman on the wheel made an error executing this last wheel order and instead applied starboard 20 wheel. Before the consequences of this error could be corrected, the ship ran aground on a mud/sand patch just south of the light on the southern end of the headland.

Two harbour tugs, which were waiting to assist the berthing operations for the ship, were called to the location and the ship was refloated using the tugs, the ship's anchor and main engine after being aground for about half an hour. Tauranga Chief continued to its berth where divers checked the ships hull externally for any damage, while it was alongside the wharf for cargo operations.

Only slight, localised scratching of the underwater paintwork on the bottom of the hull under the bulbous bow and around the forward end of the hull was reported after the divers inspection and video report so the ship was released by AMSA to continue its voyage to New Zealand.

The report concludes that the grounding was caused by an error in the execution of wheel orders during a routine course alteration. Contributing factors identified included:

• The grounding was initiated by an error in the execution of wheel orders during a routine course alteration.
• The pilot did not order midships before ordering counter rudder. This may have contributed to the helmsmans failure to recognise and act upon the change in rudder direction.
• The seaman on the wheel was possibly affected by fatigue, predominantly caused by the circadian low at the time of the incident and compounded by the effects of circadian dysrhythmia (jet lag). The concentration and reaction time of the master and OOW may also have been affected by these effects.
• The handling characteristics of the ship, due to its load and trim at the time of the incident, made the handling of the ship more difficult than usual. The following flood tide and wind on the passage down the harbour would have accelerated the rate of turn which reduced the likelihood of success of the attempted corrective actions.

The report makes recommendations relating to pilotage and crew change practices.

On 3 October 2003, Convair 580, registered ZK-KFU, was operating on a scheduled night freight flight from Christchurch to Palmerston North, New Zealand. After passing Paraparaumu Non-Direction Beacon (NDB), the crew were cleared by air traffic control for descent and approach to Palmerston North. Shortly after, the aircraft was observed on radar to enter a tightening left turn and disappear from the controller’s display. Attempts to contact the crew were unsuccessful and a search for the aircraft was commenced.

In accordance with its obligations under Annex 13 to the Convention on International Civil Aviation (Annex 13), the Transportation Safety Board of Canada (TSB) investigated the circumstances surrounding the accident involving Bell Helicopter Co 204B helicopter, registered C-GEAP, at Bonaparte Lake, British Columbia on 17 August 2003.

The pilot, the sole occupant of the helicopter, was carrying out fire suppression work and had just departed a staging site with an empty underslung water bucket. Shortly after takeoff, the engine ceased operating and, during the attempted autorotation emergency landing, the attached long line entangled a tree. The helicopter impacted the ground within a forest and was destroyed by a post-impact fire. The pilot was fatally injured.

The TSB requested that the Australian Transport Safety Bureau (ATSB) assist their investigation by sourcing specific information. In accordance Annex 13 Paragraph 5.23, the ATSB appointed an Accredited Representative to the TSB investigation to provide information related to the pilot's qualifications and recent operational history.

On completion of the TSB investigation, the final investigation report will be made available on the TSB web site.

On 10 June 2003, during a routine maintenance inspection between flights, the number 3 main landing gear wheel of a Boeing Commercial Aircraft Co. 727 freight aircraft, registered VH-VLH, was found cracked through the central hub body around the inboard bearing position. Some associated damage had been sustained by the brake unit as a result of the hub failure, however the tyre had not deflated. The adjacent number 4 wheel was undamaged. Following removal from the aircraft, the aircraft operator forwarded the wheel assembly to the Australian Transport Safety Bureau on 01 July 2003, for evaluation and analysis of the failure and consideration of the likely contributory factors.

Summary

On 24 December 2003, a Boeing 737-7BK (737) operating under the instrument flight rules (IFR) was en route from Sydney and descending for a landing at Launceston, Tasmania. A Socata TB10 (Tobago) operating under the visual flight rules (VFR) was en route from Hobart, Tasmania, to Sydney at about 7,500 ft. As the 737 was descending through about 8,300 ft, at around 1333:53 ESuT¹, the crew received a traffic advisory (TA) from their traffic alert and collision avoidance system (TCAS) about the Tobago. This was followed approximately 15 seconds later by receipt of a TCAS resolution advisory (RA) to climb. The crew responded to the RA and after arresting the aircraft's rate of descent, climbed the aircraft to approximately 9,200 ft. The pilot in command of the 737 reported that the TCAS indicated that the Tobago passed the 737 within about 200 ft vertically, slightly to the left, and certainly less than 1 NM horizontally.

Both aircraft were operating in Class E airspace that was introduced as part of the National Airspace System (NAS) phase 2b on 27 November 2003. As no prescribed separation standards are applicable in these circumstances, there was no infringement of separation standards. However, TCAS data and information obtained from the pilots of both aircraft indicate that the aircraft came into such close proximity that a threat to the safety of the aircraft may have existed. Therefore, the occurrence has been classified by the ATSB as an airprox² event, which is a type of serious incident.

¹ Eastern Summer Time.
² Under the Transport Safety Investigation Regulations 2003, an 'airprox is defined as an occurrence in which two or more aircraft come into such close proximity that a threat to the safety of the aircraft exists, or may exist, in airspace where the aircraft are not subject to an air traffic separation standard, or where separation is a pilot responsibility.

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History of the event

While taxiing for a scheduled passenger service from Sydney, NSW, to Lord Howe Island, the crew of the DeHavilland DHC-8 (Dash-8) reported that the aircraft had sustained a deflated left outboard main tyre and was returning to the departure bay. Shortly after, the cabin crewmember advised the flight crew that the tyre appeared to be 'wet' and that some passengers had seen smoke coming from the wheel area. The flight crew stopped the aircraft on the taxiway and asked the airport rescue and fire-fighting services (RFFS) to check for signs of fire. After receiving the all-clear, the passengers were disembarked and the aircraft was towed to the operator's maintenance facility.

When the pilot of the C421 requested the change to IFR, both pilots were still responsible for seeing and avoiding the other aircraft until the controller could establish a separation standard. The controller issued the pilot of the C421 with a radar heading, even though the C421, as an aircraft operating under the VFR in Class E airspace, was not subject to radar control and was not provided with an airways clearance. The AIP stated that the only radar services available to aircraft operating under the VFR within radar coverage in Class E airspace, were traffic information about other radar observed traffic on request, position information, and navigation assistance. It would have been difficult for the pilot of the C421 to assume responsibility for separation with the 737 while being radar vectored by ATC. However, the controller had issued instructions that had been acknowledged by the 737 crew, that established a 500 ft buffer between the two aircraft. The 737 crew had identified the C421 on their TCAS display and saw it during this period. A third aircraft, a Raytheon Beechcraft King Air 200, was part of the air traffic control sequence, but was not a factor in the reported occurrence.

Prior to the 27 November changes, both aircraft would have required an airways clearance and would have been provided with a separation standard. In this occurrence, all aircraft were in Class E airspace and there was no prescribed separation standard applicable, therefore there was no infringement of separation standards.

The circumstances of this occurrence constituted a non-serious airprox occurrence.

Sequence of events

On 30 November 2003, a de Havilland Canada DHC-8 (Dash 8) aircraft, registered VH-TQA, departed Sydney, NSW, on a scheduled passenger flight to Albury, NSW. Shortly after take-off, a passenger reported damage to the lower area of the window on the left side of the aircraft, at row five. After confirming the damage, the flight crew returned the aircraft to Sydney, where an inspection revealed that a propeller blade collar had separated from one of the blades of the left propeller (refer figure 1). A small piece of the separated collar, with one attaching bolt and nut, was subsequently retrieved adjacent to the departure runway (refer figure 2).

An engineering examination of the left propeller revealed that a blade collar had separated from one propeller blade. As one other propeller blade sustained damage from the collar separation, both were sent to an overhaul facility in New Zealand for examination under the supervision of the New Zealand Transport Accident Investigation Commission (TAIC).

In December 2002, a major inspection was completed on the propeller blade from which the collar had separated. In June 2003, it had undergone a trailing edge repair, due to impact damage. The blade collar was bonded to the blade root with sealant compound RTV-157, and the collar halves were also fastened by two connecting bolts, nuts and associated washers. The single recovered bolt, nut and washers were found intact with no apparent damage.

An examination of the sealant compound on the recovered section of the collar revealed that the sealant used was the correct type and specification and within its time and life expiration dates. A detailed examination of the recovered collar piece at the ATSB revealed that the collar displayed no gross manufacturing defects, but that the bonded joint gap was large and that no effective bonding had occurred on the mating surface. There was also evidence of sealant compound having been applied as a thin layer at a previous time. This film of sealant was partially covered by black paint.

A small sample of recovered RTV157 sealant was sent to a specialist laboratory for examination and comparison with a known reference sample. That examination indicated that the sealant recovered from the failed propeller blade cuff had been contaminated with a black substance giving it a different appearance from the supplied reference sample. The failed RTV 157 also contained a significant proportion of an extractable ester-based chemical that was not detected in the reference compound.

A review of the laboratory findings by the propeller manufacturer, relating to the RTV 157 compound, indicated that there were a number of potential sources of sealant contamination during assembly, installation, and operation of the propeller. However, there was not enough evidence to indicate the source of the observed contamination.

Subsequent to this occurrence, on 28 October 2004 a collar separated from the propeller of another of the operator's Dash 8 aircraft. In this instance, the collar did not impact the aircraft and was noticed missing during a subsequent pre-flight inspection. That collar had also been bonded with RTV-157 sealant.

As the entire blade collar was not recovered, a full assessment of the collar failure was not possible and factors relating to the assembly geometry of the collar could not be assessed.

As a result of the occurrence, the aircraft operator immediately initiated an inspection program of all similar propeller blade collars. That inspection revealed that five other aircraft had at least one loose propeller blade collar. All affected propeller blade collars were immediately repaired.

Subsequent to the initial fleet inspection, the operator initiated a repetitive inspection regime, requiring a visual inspection for condition and security of all propeller blade collars. Additionally, the operator issued an instruction to all propeller workshops servicing their propellers, requiring that all propeller blade collars are to be bonded using an approved alternate bonding compound, PR 1826.

Sequence of events

Shortly after selecting the landing gear up after departure on a flight from Brisbane to Barcaldine on 27 November 2003, the crew of the de Havilland Canada DHC-8-202 (Dash 8), registered VH-SDA, observed the number-two hydraulic pump caution light illuminate, followed by a zero hydraulic pressure indication. The number-two hydraulic system powered the aircraft's roll spoilers, ground spoilers, parking brakes, nose wheel steering and landing gear extension and retraction. The crew diverted back to Brisbane and extended the landing gear manually for the landing. The failure of the hydraulic system pressure was traced to the failure of a flexible hydraulic hose in the nose landing gear actuation system, which allowed the loss of system pressure and hydraulic fluid.

The failed component was forwarded to the Australian Transport Safety Bureau in Canberra for examination. The flexible hydraulic hose, part number DSC252B4-0124, failed at 12,369 cycles since new and had been installed since the aircraft's manufacture. When first introduced into operation, the hose life limit was set at 15,000 cycles. However, the aircraft operator indicated that a company replacement life limit of 13,000 flight cycles had been introduced in response to a history of failure of the same or similar hoses in the Dash 8 landing gear system.

Examination by the ATSB found the hose had failed by localised rupture at the point of swaged connection to an end fitting. Associated with the rupture was evidence of fatigue cracking and breakage of the external reinforcing braid wires, with cracking also found to a lesser degree on the opposite side of the connection. There was no evidence suggesting that a manufacturing or material defect had contributed to the hose failure. Assembly diagrams showed that the hose failed at the point of maximum flexure when the landing gear was extended or retracted.

Failure of the hose was attributed to the localised fatigue cracking and breakdown of the external braided hose reinforcing sheath and the subsequent rupture of the tubular core in the absence of the support afforded by the sheath. In-service flexures of the hose and pressure cycles and pulsations inherent in the operation of the aircraft's hydraulic system were considered to be likely contributory factors.

The hose failed 631 flight cycles before it was due for removal in accordance the aircraft operator's maintenance schedule. Given that the failure was a result of a fatigue cracking mechanism and there has been a history of similar occurrences, it would be expected that the identified cycles-to-failure for any such component would lie within a distribution represented by lower and upper limits ('outliers'). While most of the failures would occur between those limits, there remains a probability that some components may fail before the lower limit, or indeed after the upper limit. The establishment of a service life limit for a component based on the distribution takes into account the criticality and acceptability of component failure and hence, the necessary confidence level in defining a service limit for removal of the item before failure.

The evidence to hand suggests that this flexible hydraulic hose failure was a distribution 'outlier'. Given that the reliability of the assembly is being managed by life limiting the susceptible component, and the loss of a hydraulic system in this case was able to be managed using existing aircraft flight manual procedures, no Bureau recommendation has been made with respect to the maintenance philosophy applied to that system.

Aircraft operator

As a result of this occurrence, the aircraft operator reported that the task cards for the job were amended and that they now require that the wiring looms and other components in the area of the stowage bins are to be inspected to ensure adequate clearance from the bins and the structure.

Aircraft manufacturer

During the comment period for the draft report, the aircraft manufacturer was requested to review the installation procedures for 747 overhead bins, to assess the benefit of including a requirement to ensure adequate clearance between the stowage bins and any adjacent structure, wiring looms and other components.

The aircraft manufacturer responded to the draft report and advised:

Based on this incident, our Service Engineering and Maintenance Manual departments reviewed the need for an inspection note for wire bundles when installing the overhead stowage bins. The results of that review were as follows:

• As stated in the draft report, the current Boeing task cards do not provide instructions on how to manage wire bundles upon re-installation of the stow bins. Instead, wire separation information including minimum clearance requirements for wire bundles is provided to operators in section 20-10-11 of Boeing Standard Wiring Practices Manual (DC-54446). Thus, the wire separation requirement is already documented to the maintainer, just not on the specific task card.
  
   
• We depend on the maintainer to possess the necessary minimum skills to return the airplane to a serviceable condition. As such, a maintainer installing stow bins should already be aware of minimum wire bundle clearance requirements. Thus, we believe that the existing maintenance documentation, along with standard practices expected of the maintainer, already addresses this issue.
  
   
• We searched our service history records and could not find any other occurrences of this issue. Thus, the 30+ years of service history we have on the 747 fleet shows that this has not been a problem with the in-service fleet.
  
   

As a result, we do not feel it is necessary to amend the stow bin installation task cards to include a requirement for inspection of wire bundle clearances. Of course, each operator could include such a requirement at their discretion.

¹ The 'C' zone is the zone on the main deck between the main cabin doors 2 and 3.
² The 'D' check is the most intensive maintenance check on an aircraft.