Smoke

A Fokker F27-50 aircraft, registered VH-FKZ, had departed Adelaide Airport, SA, on a scheduled passenger service to Olympic Dam SA. During the initial climb, the cabin crew advised the flight crew that there was smoke haze in the cabin. The flight crew returned the aircraft to Adelaide Airport with no reported injuries.

An examination of the right engine indicated that the number-4 bearing had failed.

On 19 October 2006, at about 0635 Eastern Standard Time the crew of a de Havilland Canada DHC 8-200 aircraft, registered VH-TQX, departed from Melbourne Airport, Vic on a scheduled flight to Wollongong NSW. At about 0645, as the aircraft was climbing through flight level 140, the pilot in command (PIC) detected smoke in the aircraft. Soon afterwards a smoke detector warning sounded in the aircraft toilet and the flight and cabin crew observed smoke haze. The flight crew reported the situation to air traffic control (ATC) then diverted the aircraft to Melbourne and carried out the appropriate recall and checklist actions. The aircraft landed in Melbourne on runway 16 at 0658. There were no reported passenger or crew injuries.

The manufacturer's examination of the engine showed that oil had leaked from several compressor bearings into the low-pressure compressor of the engine. The high temperature of the compressed air and the engine components caused the oil to vaporize, contaminating the air extracted from that engine section to the aircraft cabin. The manufacturer had previously issued three service bulletins recommending engine modifications pertinent to this occurrence. Compliance with the bulletins was optional. However, the operator had already modified about 90% of the affected engines in its fleet at the time of the incident. The operator has planned to modify the remaining engines at the next period of scheduled or unscheduled maintenance.

The crew's timely assessment and response to the in-flight emergency reduced the likelihood of an extended exposure to the fumes by the passengers and crew. Also, the initiation of an emergency phase by air traffic control ensured that appropriate services were available to assist the crew after the aircraft had landed.

The engine manufacturer has undertaken to update the Workscope Planning Guide for the PW 123D engine to improve its resistance to internal oil leakage.

On 15 June 2006 at approximately 1630 Eastern Standard Time, during a scheduled flight from Hervey Bay, Qld, to Brisbane, Qld, the crew of the Fairchild Industries SA227-AC (Metro III) aircraft, registered VH-SEF, noticed that the cabin temperature was colder than desired. After adjustment to the auto and manual cabin temperature controls, the cabin temperature increased to a higher-than-expected range and could not be reduced. Shortly after, smoke was seen coming from the right-side cockpit air vents. The crew isolated the right bleed air system and diverted the aircraft to Maroochydore, Qld.

After examination of the aircraft's air-conditioning system, the right hot air mixing valve was replaced and the aircraft returned to service without further problem.

During the incident, the crew found that fitment of their emergency oxygen masks was ineffective, requiring them to hold the masks in place with one hand, and that the passenger address system was also ineffective in alerting the passengers to the emergency.

Only one minor injury in the form of sore ears was reported as a result of the incident.

As a result of this incident the Australian Civil Aviation Safety Authority issued an Airworthiness Bulletin to address maintenance aspects of flight crew oxygen masks.

At 1350 Eastern Standard Time on 19 March 2006, an Airbus A330-303 aircraft, registered VH-QPB, commenced take-off on runway 19 at Brisbane Airport, Qld, on a scheduled passenger service to Singapore. The pilot in command (PIC) was the pilot not flying (PNF) and the copilot was the pilot flying (PF) for the sector. Visual meteorological conditions prevailed at Brisbane.

During the take-off roll, the flight crew noticed a significant discrepancy between the PF and PNF's airspeed indications and the PIC assumed control of the aircraft and rejected the take-off. The PIC elected to not use reverse thrust and attempted to manually disconnect the autobrakes via brake pedal deflection during the rejected take-off.

Shortly after vacating the runway, the flight crew noted increased brake temperatures and selected the brake cooling fans ON. During the taxi, the brake temperatures continued to rise and became excessive. The fusible plugs on six of the eight main landing gear wheels melted and the respective tyres deflated. There were no injuries to the crew or passengers.

A post-flight engineering inspection of the aircraft found what appeared to be wasp-related debris in the PIC's pitot probe and the operator determined that the contamination was a probable contributory factor in the incident.

The operator and airport owner undertook a number of safety actions to minimise the risk of future wasp activity at Brisbane Airport.

At approximately 0530 Eastern Standard Time hours on 9 December 2005, a Fairchild Industries Inc SA227-AC Metroliner, registered VH-EEQ was being operated on a scheduled cargo flight from Rockhampton to Mackay, Qld with a crew of two pilots on board. The crew reported that, during the cruise at flight level (FL) 140, an oily smell was detected emanating from the right nozzle cockpit air vent. Shortly after, and at a position 85 NM north-north-west of Rockhampton, the crew noticed smoke in the cockpit.

Although the crew reported completing the relevant checklist actions, the smoke re-entered the cockpit on two more occasions and the crew diverted to land back at Rockhampton. The third instance of smoke being detected in the cockpit followed shortly after the right engine oil temperature 'approached the top of the green arc' and, in the belief that to do so would prevent more smoke from entering the cockpit, the crew shut down the right engine.

A local engineering examination of the aircraft found that the air cycle machine had failed, releasing lubricating oil mist and smoke into the aircraft's air-conditioning ducts. In addition, that examination revealed that the indicated increased right engine oil temperature was as a result of an indicating system malfunction.

As a result of this incident, a number of safety actions were carried out, or proposed to be carried out, including:

• by the operator, to:
  • amend its operations manual to remove non-type specific instructions that conflict with approved flight manual (AFM) procedures
  • advise its pilots of the Civil Aviation Safety Authority's (CASA) expectations in regard to the application of the word 'recommended' in AFM Emergency Procedures
  • advise its Training Captains to include CASA's expectations for the application of the word 'recommended' in AFM Emergency Procedures in all endorsement training
  • by CASA, which published its interpretation of the term 'recommended' in relation to the required conduct by pilots of aircraft manufacturer's emergency checklist procedures.

The Australian Transport Safety Bureau did not conduct an on-scene investigation of this occurrence. The report presented below was prepared principally from information supplied to the Bureau.

REPORTED INFORMATION

At 1151 Eastern Standard Time, on 11 October 2004, while in cruise at FL230, the pilots of a DHC-8-315 aircraft, registered VH-SBV, operating a scheduled flight from Horn Island to Cairns, Queensland, noticed the presence of smoke in the flight deck, which was followed by a loud bang emanating from a panel behind the pilot in command's (PIC) seat.

At the same time, a number of warning lights illuminated, including the primary and auxiliary inverter annunciations. The PIC's electronic horizontal situation indicator, attitude director, altimeter and vertical speed indicator instruments lost electrical power, so control of the aircraft was handed over to the copilot.

Because of the presence of smoke, the pilots donned their oxygen masks, commenced an emergency descent and conducted `Oxygen' and `Fire and Smoke' drills. By the time those drills had been completed, the smoke had dissipated enough to allow the removal of the oxygen masks, and the aircraft was levelled at 10,000 feet.

Inspection of the panel behind the PIC's seat identified a problem with the primary inverter. After completing the appropriate emergency procedures listed in the Quick Reference Handbook (QRH), the primary inverter was isolated and the auxiliary inverter selected, however, the PIC's instruments did not resume operation.

As the smoke had dissipated rapidly from the flight deck and the primary inverter had been isolated, the crew elected to continue to Cairns where a normal approach and landing was carried out.

A subsequent examination by the operator's ground engineers confirmed that the primary inverter had failed creating a power spike that resulted in a number of circuit breakers (CB) tripping, including the auxiliary inverter CB. The tripping of the auxiliary inverter CB prevented the restoration of electrical power to the PIC's instruments.

After resetting the auxiliary inverter CB and functionally testing the system, the aircraft was flown to Brisbane, under the provisions of the minimum equipment list, where the primary inverter was replaced, and the aircraft was returned to service.

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.

The engine bearing seals normally protected the bleed air supplied to the air conditioning packs from oil contamination. A technical defect in one or more of the seals resulted in oil entering the flight deck air conditioning system, with the first indication of the defect being an awareness of smoke on the flight deck. The flight crew correctly donned their oxygen masks as the first step in addressing the problem and then proceeded to comply with the emergency checklist by landing at the nearest suitable airport.

The difficulty that the crew faced in correctly determining the source of the smoke resulted in the initiation of a non-normal checklist that was not pertinent to the situation. The aircraft manufacturer's subsequent revision of the QRH, simplifying and clarifying the checklists, has diminished the likelihood of a similar occurrence. As the incident took place during daylight hours, in visual meteorological conditions close to the departure airport, the potential to affect the safety of flight was limited. It is considered that if the smoke event had occurred later in the flight, the crew would have had more time to carry out the checklist procedures and successfully isolate the source of the smoke.

The possibility that the air conditioning system was supplying contaminated air to the flight deck while the crew was carrying out the emergency procedure for electrical smoke, highlights the importance of crews donning oxygen masks at the first sign of fumes or smoke contamination of flight deck air.

Local safety action

As a result of this occurrence, the aircraft operator has taken action to re-route the PTT wiring away from the circuit breaker supply bus and removed sharp edges from the panel housing to prevent wire chafing.

Local safety action

As the incident was the second failure of this part number air cycle machine, the operator, in consultation with the component manufacturer, initiated preventative actions to minimise such failures. Those actions included:

1. cleaning the airconditioning heat exchanger every 2,500 hours in lieu of 10,000 hours;
2. operating the air cycle machine with a different oil; and
3. decreasing the intervals between oil level inspections.