On 5 April 2006, the pilot of an amateur-built Lancair 360 aircraft, registered VH-ZNZ, was conducting circuits at Bankstown Airport, NSW. It was the aircraft's first flight since being repaired after a landing accident in 2003.
Following an overflight and a touch-and-go, the pilot conducted another touch-and-go and shortly after lift-off, at an altitude estimated by witnesses to be between 100 ft and 400 ft, the engine was heard to malfunction. Almost immediately, while still not above 500 ft, the aircraft rolled into a steep right turn. Engine power was heard to return but sounded intermittent. After turning approximately 90 degrees, the aircraft rolled out of the turn momentarily to about wings level, before the turn steepened again to the right. The aircraft was observed to roll further to the right and descend steeply. The aircraft impacted a taxiway, the pilot was fatally injured, and the aircraft destroyed.
The investigation found that the engine power loss was probably due to interruptions of fuel flow to the engine but could not conclusively determine the reason. The aircraft stalled at a height insufficient to allow the pilot to recover.
The investigation identified a number of safety issues related to stall warning, management of incomplete engine power loss after take-off, pilot transition training and the provision of information to purchasers of amateur-built aircraft.
Following the occurrence, the Civil Aviation Safety Authority and Sport Aircraft Association of Australia implemented a number of safety actions. As a result of this and other occurrences the Australian Transport Safety Bureau initiated a broader investigation into loss of control following engine power loss after take-off.
On 26 March 2006, at about 1800 Eastern Daylight-saving Time, a Cessna 188B Agwagon aircraft, registered VH-ZIP, was reported to have taken off from a field adjacent to a local water-ski area, about 59 km south-west of Narrandera, NSW, with the pilot as the sole occupant. The following morning at about 0900, the aircraft wreckage was found by a passer-by at a position 55 km south of Narrandera and about 8 km from the departure area. The aircraft was destroyed, there was no fire, and the pilot was fatally injured.
There was no evidence that the pilot experienced any physiological condition which could have contributed to the accident. Weather conditions in the area were reported to be fine with little or no wind and there were no overhead powerlines or other obstacles in the vicinity. The aircraft had impacted the ground heavily, in a nose-down, right wing-low attitude, consistent with a low-speed stall or aerobatic manoeuvre. There was no evidence of a flight control or systems problem which could have contributed to the accident and the engine and propeller were producing power at the time of impact.
The pilot was reported to have been known to conduct 'high-risk' aerial activities, including aerobatic flight in agricultural aircraft. A number of photographs taken shortly before the final flight showed him conducting low passes over the water-ski site with the aircraft's main wheels in contact with the surface of the water. During the accident flight he was reported to have conducted very low passes over a departing vehicle, more low passes over the water with the main wheels in contact with the water's surface and what was described to be manoeuvres consistent with aerobatic flight.
The investigation concluded that the pilot was probably conducting an aerobatic flight manoeuvre from which collision with terrain could not be prevented.
At 0728 Eastern Standard Time on 31 March 2006, an amateur-built Lancair 320 aircraft, registered VH-BST, departed Townsville, Qld, on a private flight to Archerfield Aerodrome, Qld. The pilot, who owned the aircraft and was the sole occupant, had earlier submitted a visual flight rules (VFR) flight plan for the flight.
At 1048.30, the pilot contacted the Archerfield Aerodrome Controller and reported that he was 19 miles (35 km) from the aerodrome and inbound. He said that he was new to the area and would appreciate any help. The controller advised the pilot to report at the TV towers, a VFR reporting point 13 km north-west of Archerfield. The aircraft was maintaining about 3,700 ft AMSL (above mean sea level).
The pilot reported at the TV towers but had difficulties finding the aerodrome. Radar data showed that the aircraft was 2 km north of the aerodrome at 1,700 ft AMSL, and tracking south-south-east. At 1058.11, the controller asked the pilot if he had the aerodrome in sight. The pilot said that he did not, and said 'I feel I've overflown it'. The controller advised that radar information indicated that the aircraft was north of the aerodrome, and he suggested that the pilot continue to turn left. The pilot then acknowledged that transmission. No further radio transmissions were received from the pilot.
Witnesses reported seeing the aircraft's left wing drop and the aircraft appeared to enter a spin before descending straight down, colliding with a tree and then a creek running parallel to Kessels Road, Coopers Plains. The aircraft was destroyed and the impact was not survivable.
Summary
At 0728 Eastern Standard Time on 31 March 2006, an amateur-built Lancair 320 aircraft, registered VH-BST, departed Townsville, Qld, on a private flight to Archerfield, Qld. At 1058, shortly after flying past the destination airport, the aircraft departed controlled flight and impacted the ground. The aircraft was destroyed and the pilot sustained fatal injuries.
The loss of control was consistent with an accelerated aerodynamic stall, at a height from which it was not possible to recover, followed by the aircraft entering a spin to the left prior to impact. The loss of control occurred when the pilot was operating in adverse weather conditions of low cloud, was tracking towards an area of reduced visibility in rain and towards terrain that was higher than the aircraft.
The pilot's decision to continue the flight into instrument meteorological conditions, even though neither he nor the aircraft were certified to operate is those conditions, increased safety risk. The pilot's ability to fly the aircraft and manage the flight was limited by his relative lack of experience on high performance aircraft, and deficiencies in the training that he had received on the Lancair.
Some aerodynamic and flight control characteristics of the Lancair 320 aircraft increased the risk of an accident. However, those characteristics were largely a consequence of the role for which the aircraft had been designed. In order to operate Lancairs and other high-performance amateur-built experimental aircraft safely, pilots need to be aware of, and maintain the aircraft within, the safe operational envelope.
In response to this and other accidents involving amateur-built experimental aircraft, the ATSB is conducting further research on safety aspects of these types of aircraft.
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.
On 4 March 2006, McDonnell Douglas Corporation MD-82, registered PK-LMW, was operating a flight from Denpasar to Surabaya, Indonesia. The aircraft was cleared to land on runway 10 with the reported wind calm and the runway wet. During the landing roll, the aircraft veered to the right resulting in a runway excursion.
The National Transportation Safety Committee (NTSC) of Indonesia was responsible for investigating this occurrence. On 8 March 2006 the NTSC requested assistance from the Australian Transport Safety Bureau (ATSB) in the recovery and analysis of information from the flight data recorder and cockpit voice recorder.
In accordance with clause 5.23 of Annex 13 to the Convention on International Civil Aviation, the ATSB appointed an Accredited Representative to assist the NTSC and initiated an investigation under the Transport Safety Investigation Act 2003.
The NTSC is responsible for releasing the final investigation report regarding this occurrence.
National Transportation Safety Committee Ministry Of Transportation Republic Of Indonesia Transportation Building 3rd Floor Jalan Medan Merdeka Timur No. 5 Jakarta Pusat 10110 Indonesia
On 4 August 2005, a Piper PA-31-350 Chieftain aircraft, registration VH-MZM, departed Dubbo Airport, NSW, for a local post-maintenance acceptance flight following an engine change. Shortly after departure, the pilot reported that the right engine manifold pressure fluctuated then dropped and maintained 28 inHg. The aircraft was returned to Dubbo with reduced power to the right engine.
Examination of the aircraft by the overhaul engineers revealed the newly-installed turbocharger turbine wheel had failed. The turbocharger was supplied to the ATSB for further examination and analysis.
During the course of the investigation, a second, similar turbine wheel failure occurred in a Piper PA-31-350, registration VH-TZY. Similarly to the first incident, the pilot observed significant manifold pressure fluctuations during cruise flight of the aircraft and the right engine was shut down. The aircraft was returned to the departure aerodrome. The turbocharger had been in service for approximately 241 hours and was subsequently forwarded to the ATSB.
Analysis of both turbine wheels revealed fracture characteristics indicative of a fatigue cracking mechanism. The failures had both occurred through a sealing ring groove, adjacent to the friction-welded joint between the turbine wheel and shaft components. While the post-failure damage of the fracture surfaces in both instances prevented the identification of the prime factor/s giving rise to the initiation of fatigue cracking, it was likely that the stress-raising effect of the ring groove location, geometry and associated microstructure, when combined with pre-existing cyclic loading conditions, was sufficient to initiate fatigue cracking and consequent turbine wheel failure.
The ATSB has completed its technical analysis report of the flight recorder data from the Boeing Co. 737-329, registration PK-KKE on behalf of the Indonesian National Transportation Safety Committee. The aircraft was operating a flight from Jakarta to Makassar, Indonesia when it was involved in a serious (navigation related) incident while enroute. The crew landed safely at Tambolaka in Sumba.
The National Transportation Safety Committee (NTSC) of Indonesia is responsible for investigating this occurrence. The NTSC requested assistance from the Australian Transport Safety Bureau (ATSB) in the recovery and analysis of information from the flight data recorder and cockpit voice recorder. In accordance with clause 5.23 of Annex 13 to the Convention on International Civil Aviation, the ATSB appointed an Accredited Representative to assist the NTSC and initiated an investigation under the Transport Safety Investigation Act 2003.
The ATSB's Technical Analysis Report has been sent to the NTSC to assist its ongoing investigation. The NTSC is responsible for releasing a final investigation report regarding this occurrence.
National Transportation Safety Committee Ministry Of Transportation Republic Of Indonesia Transportation Building 3rd Floor Jalan Medan Merdeka Timur No. 5 Jakarta Pusat 10110 Indonesia
The ATSB has amended this report to clarify its role in the assistance that was given to RA-AUS regarding the examination of components recovered from the aircraft. It is possible that some information in the Abstract and Executive Summary of the original report may have conveyed a broader meaning than was intended.
___________________
During the investigation of two fatal microlight accidents, Recreational Aviation Australia (RA-AUS) requested the assistance of the Australian Transport Safety Bureau (ATSB) in conducting technical examination and analysis of parts recovered from the accident sites.
The first accident occurred in Atherton, Qld (registration 32-4456) on 20 October 2005 and the second in Cessnock, NSW (registration 32-4388) on 21 January 2006. During the course of the investigation a third fatal accident was identified. The third accident had occurred in Hexham, NSW (registration T2-2625) in 1996, with coronial findings (0063/96) delivered on 25 March, 1997.
In all three accidents, the failure of the main wingspar had occurred near the wingtip. Qualitative analysis of the structural design and loading of the part during this safety investigation and examination of the coronial findings from the Hexham accident, revealed that the main wingspar had failed under negative 'G' loading. Such loading was likely if the aircraft entered or encountered flight conditions outside the manufacturer's specified flight envelope.
A rigid propeller shaft (part number 3102572-2) from an
Allied-Signal (Honeywell) TPE331-12 turboprop engine, was received
and examined by the ATSB in order to characterise and assess the
nature of an unusual and irregularly finished surface at the end of
the forward main bearing/seal journal. The anomalous area had been
originally identified during inspection by the engine maintenance
provider, who subsequently referred the matter to the Civil
Aviation Safety Authority (CASA) through their service difficulty
reporting (SDR) system.
The ATSB laboratory examination identified the features
associated with the ends of the journal surface as being
characteristic of surfaces that had been manually dressed following
the application of a plasma/metal sprayed coating to re-build the
journal surfaces. Subsequent reference to the inspection/repair
manual for the propeller shaft, confirmed that plasma spraying was
an approved process for journal repair, and that hand-finishing and
deburring was specified for post-spray dressing.
Previously published - Interim Factual Information
Soon after the aircraft reached the planned cruise altitude of FL340, the flight crew observed that the speed indicated on the primary flight display for stick shaker activation was converging towards their current airspeed. The stick shaker activated as the speeds merged and the crew commenced an immediate descent. There was a breakdown in the relevant procedural separation standard as the aircraft descended through the cruise level of an opposite direction aircraft.
Descending through FL290 the speed indicated for stick shaker activation returned to normal and the stick shaker warning ceased. The flight continued to its destination without further incident.
FACTUAL INFORMATION
At approximately 0855 Western Standard Time, on 28 February 2006, a Boeing Company 717-200 aircraft, registered VH-NXH, was being operated on a scheduled passenger service from Paraburdoo to Perth, WA. The aircraft was being operated by two flight crew and four flight attendants and carried 66 passengers. The brakes-release weight at Paraburdoo was 44,837 kg.
The weather conditions for the flight were under the influence of a decaying tropical cyclone that had crossed the north-west coast of Western Australia earlier that day. Rain and heavy cloud persisted through most of the region and the aircraft was operating in instrument meteorological conditions. The meteorological forecast indicated a temperature of -39 degrees C at the aircraft's planned cruise altitude.
The flight crew had selected engine anti-ice ON during the climb. The autopilot was engaged and had captured the planned cruise altitude of FL340. The airspeed, body angle and engine power settings were normal for that stage of flight and the aircraft was accelerating normally to cruise speed. During that period, the flight crew detected that, over a period of several seconds, the speed displayed on the primary flight display (PFD) for stick shaker activation (Vss) began converging towards the current indicated airspeed. The speed indicated for Vss appeared to overtake the amber caution foot associated with the flight management computer (FMC) calculated minimum operating speed (Vmin), which appeared to be remaining stationary, rather than moving in conjunction with the Vss indication. The relevant indications on the aircraft's PFD are annotated at Figure 1.
Figure 1: Primary flight display and airspeed tape
The stick shaker 1 warning activated as Vss merged with the current airspeed and then continued to increase and merge with the maximum operating speed (V/MoM/Mmo), with the right edge of the airspeed tape giving the appearance of one continuous red chevron 2 'zipper'. Similar indications were observed on both pilots' PFDs. The crew reported that they did not receive any other cautions, alerts or warnings on the aircraft's engine and alert display.
The flight crew recalled that, although the pitch limit indicator 3 had turned red, indicating that the aircraft was at or near a stalled condition, there was no "STALL" annunciation on the PFD, nor any aural "STALL STALL" warning or klaxon alert. The crew initiated an immediate on-track descent and advised air traffic services (ATS) of their requirement to change level. The stick pusher stall recovery system did not activate, and the crew did not identify any secondary indications of an impending stall, such as aerodynamic buffet or an abnormally high pitch attitude. Although the crew did not detect any evidence of airframe ice on the windscreen or windscreen wiper posts, they selected the airframe anti-ice ON. The crew did not otherwise change the configuration of the aircraft.
The stick shaker continued to operate as the aircraft was descended at approximately 2,000 ft per minute. The flight crew recalled that the speed indicated on the PFD for Vss returned to normal as the aircraft descended through FL290 and that the stick shaker warning ceased at that time.
During the descent, there was a breakdown in the relevant ATS procedural separation standards, as a result of the aircraft descending through the level of an opposite direction aircraft.
The flight crew levelled the aircraft out at FL280 with all of the aircraft's controls and system indications 'normal'. Once the in-flight weather conditions improved, the crew climbed the aircraft to FL300, and the flight landed at Perth without further incident.
Company maintenance engineers performed a built-in test equipment check 4 following the aircraft's arrival in Perth. That check confirmed that no faults had been recorded during the occurrence flight and the aircraft was released for service. Subsequent flights were completed without incident.
The aircraft's flight data recorder (FDR) and the electronic recording media for the quick access recorder (QAR) were removed for analysis. Data was also recovered from the non-volatile memory of the aircraft's flight control computers (FCC).
The FDR data indicated that the output from each of the aircraft's angle of attack (AoA) sensors became static (continuously indicating about 4 degrees AoA) passing FL287 on climb, at a total indicated air temperature (TAT) of -4 degrees C. The stick shaker activated approximately 80 seconds after the aircraft had reached FL340, as it was accelerating through a computed airspeed of 258 kts and at a TAT of -10 degrees C. About 14 seconds later the recorded data indicated the commencement of a descent from FL340. The stick shaker indication continued for another 2 minutes 23 seconds, ceasing as the aircraft passed FL288, at a computed airspeed of 308 kts and a TAT of approximately +7 degrees C. Associated with the cessation of the stick shaker warning was the AoA sensors returning to normal operation.
The QAR media was found to contain no recorded data. Examination of that file indicated that the recording media was incorrectly formatted for use in the QAR.
The manufacturer of the aircraft's FCC analysed the contents of each computer's non-volatile memory. That analysis revealed no fault history data for the day of the incident.
On 03 March 2006, an entry was made in the aircraft's maintenance log, reporting the intermittent operation of the air data heat switch 5 annunciator after the system was selected OFF following landing. An indicating globe was replaced and the switch tested serviceable before the aircraft was returned to service.
The aircraft's AoA sensors and air data heat switch were subsequently removed from the aircraft and dispatched for examination by the component manufacturers under the direct supervision of the US National Transportation Safety Board (NTSB).
The investigation is continuing, and will include:
analysis of the FDR data and the movement of the AoA sensor in the periods immediately preceding and immediately after the sensors were returning a static (not moving) indication
analysis of results from component testing
evaluation of input from the NTSB, aircraft and component manufacturers, regarding systems analysis and modes identified for anomalous stick shaker operation.
The stick shaker is a tactile warning to alert the crew that the aircraft is at or near an aerodynamically stalled condition of flight. It is one of several warning systems designed to alert the crew of that flight condition.
The red chevron normally indicates airspeeds above VmoMmo and airspeeds below Vss.
The pitch limit indicator depicts the difference between the aircraft angle of attack (AoA) and stick shaker AoA.
Examination of fault codes that have been stored for maintenance checkout and fault isolation.
This switch provides anti-ice protection to the aircraft's pitot-static, AoA and ram air temperature sensor systems.
Summary
On 28 February 2006, a Boeing Company 717-200 aircraft, registered VH-NXH, was being operated on a scheduled passenger service from Paraburdoo to Perth, WA. The flight was being conducted under the instrument flight rules (IFR). Onboard the aircraft were two flight crew, four cabin crew and 66 passengers. The aircraft departed Paraburdoo at about 0837 Western Standard Time and was in instrument meteorological conditions (IMC) during the climb.
The stick shaker stall warning system activated soon after the aircraft reached top of climb at Flight Level (FL) 340 and while the aircraft was accelerating to cruise speed. The flight crew did not receive any 'STALL' annunciation on their respective primary flight displays, nor any 'STALL STALL' aural warning or klaxon alert.
The flight crew initiated an immediate on-track descent and advised air traffic services of their requirement to change level. There was an infringement of the relevant procedural separation standards as the aircraft descended through the cruise level of an opposite direction aircraft.
An analysis of the flight recorder data indicated that the activation of the stick shaker was as a consequence of the angle-of-attack sensors becoming static during the climb. The investigation concluded that the immobilisation of the angle-of-attack sensors was consistent with ice restricting the movement of the 'slinger' on which the sensor vane is mounted.
The investigation assessed that the aircraft was not near a stalled condition of flight when the stick shaker warning activated. However, because the angle-of-attack sensors provided input to the aircraft's stall warning system, the immobilisation of those sensors adversely affected the reliability of the aircraft's stall warning system and could have render the automatic stall recovery system inoperative.
As a result of this incident, the aircraft and angle-of-attack sensor manufacturers initiated a detailed design review of the angle-of-attack sensor.
