Control - Other

The aircraft was in clear air, descending through FL165, at an indicated airspeed of 270 kts, with the centre autopilot engaged. As the speed brake handle was moved from the closed position the aircraft rolled rapidly from a wings level attitude to some 20 degrees right bank. The first officer disconnected the autopilot and recovered to wings level. The autopilot was subsequently re-engaged and operated normally. An Engine Indication and Crew Alerting System (EICAS) message (Spoilers), and associated spoiler indicator light, remained illuminated for the remainder of the flight. One flight attendant was slightly injured during the incident.

Flight data recorder information revealed no unusual flight control inputs associated with the event. Ground inspection revealed that a fault event had been recorded by the No.2 Spoiler Control Module (SCM), but that fault could not be duplicated during ground testing. The operator carried out extensive troubleshooting of the complete system in conjunction with the manufacturer, without detecting any faults. The SCM was replaced as a precaution and the operator plans to install upgraded modules as they become available.

The pilot advised that during the landing roll on bitumen runway 36, the aircraft swung sharply to the right. He applied left brake to correct the swing. The aircraft began to straighten but then it veered sharply to the right again like a ground loop. The left landing gear leg collapsed, and the left wing struck and propeller struck the ground. At the time, the wind was gusting 10 to 15 knots from 010 degrees.

After the accident, the pilot thought that the left brake might have failed causing him to lose directional control. An engineer inspected the brakes and advised that there was no evidence of a brake failure. However, the engineer rebuilding the aircraft discovered a pre-existing fatigue crack through about half the left landing gear leg. It is probable the fatigued landing gear leg failed during the landing roll.

According to the engineer, the landing gear legs in VH-ICA were of the thicker metal version. Therefore, they were not subject to mandatory magnetic particle method crack testing as were the earlier version of spring legs in accordance with Airworthiness Directive AD/Cessna 188/3.

Significant Factors

This accident was not the subject of an on-scene investigation and there was insufficient evidence available from other sources to determine the factors that led to the accident.

Safety Action

The maintenance organisation rebuilding VH-ICA advised that a defect report would be submitted to the Civil Aviation Authority concerning the pre-existing crack found in the landing gear leg.

The Bureau of Air Safety Investigation advised the Civil Aviation Authority of the fatigue crack by way of the Bureau's weekly summary of occurrences.

The student pilot was conducting solo circuits on runway 11 right. The sky was clear, and the wind was from the east at about 10 kts, with a slight crosswind component.

The pilot flew several circuits without incident. The final approach and touchdown were normal, but during rollout, the aircraft veered to the left and the pilot was unable to regain directional control. The nose landing gear collapsed, and the propeller and right wingtip struck the runway.

It is likely that the pilot relaxed elevator control back pressure after the mainwheels contacted the runway, causing a rapid weight shift to the nose gear. The slight crosswind may also have contributed to the loss of directional control.

The pilot assessed the wind as from 180 degrees at 10-15 kts. On the take-off roll on strip 09 the tail was raised, and the aircraft appeared to accelerate normally. It then encountered a wind gust. The right wing rose, and the aircraft diverted left. The left main wheel contacted a drain on the left side of the strip and the aircraft overturned and came to rest inverted.

Significant Factors

The following factors were considered relevant to the development of the accident:

1. Decision by the pilot to operate in a gusty crosswind.

2. Probable encounter with a wind gust.

3. The pilot was unable to maintain directional control.

The pilot reported that shortly after touchdown, he heard a noise followed by vibration from the nosewheel area. He subsequently lost directional control of the aircraft which came to rest beyond the left side of the runway. Post-flight inspection revealed that the nosewheel had collapsed, and that the propeller and left-wing tip were damaged. It appeared that the pilot overcontrolled with the elevator after the initial touchdown.

The pilot reported that during two attempts to land on Runway 08 he experienced handling difficulties with the aircraft. He eventually landed on Runway 05. An inspection subsequently revealed the propeller had suffered a ground strike and the left main landing gear door was open.

A gusting crosswind of 15 to 25 knots was reported at the time of the occurrence.

Investigation determined that the locking balls were missing from the left main gear door actuator which would allow the door to open if hydraulic pressure was lost. An intermittent open circuit was also detected in the gear extend circuit. This defect caused the hydraulic pump to stop intermittently and may have resulted in the left door opening in flight.

Had the left main gear door opened during the landing sequence it may have contributed to the handling difficulties experienced by the pilot in the gusting crosswind conditions.

During recovery from a stick shaker exercise, as part of an endorsement sequence, the aircraft departed from controlled flight prior to the speed reducing to the published stick shaker speed. Recovery was reported to have taken approximately 1800 feet. The aircraft was returned to maintenance for investigation.

During the maintenance investigation, three minor leaks were found from butt straps on the left-wing leading edge. Advice from the manufacturer was that such leaks could definitely affect the stalling behaviour of the aircraft. The leaks were rectified and a subsequent test flight confirmed stalling characteristics were normal.

Section 21 (2) of the Transport Safety Investigation Act 2003 (TSI Act) empowers the Australian Transport Safety Bureau (ATSB) to discontinue an investigation into a transport safety matter at any time. Section 21 (3) of the TSI Act requires the ATSB to publish a statement setting out the reasons for discontinuing an investigation.

On 15 October 2014, the ATSB commenced an investigation into a reported vertical speed exceedance involving an Embraer ERJ 190, VH-ZPN, near Hobart Airport, Tasmania on 1 October 2014.

Examination of the information collected during the investigation indicated that the aircraft did not exceed the allowable vertical speed and that the event did not constitute a Transport Safety Matter under the Transport Safety Investigation Act 2003.

On that basis, the ATSB has decided to discontinue the investigation.

On 4 January 2013, a Boeing 737-800 registered VH-VUZ, departed Launceston, Tasmania on a scheduled passenger service to Melbourne, Victoria. During departure, the crew selected level change (LVL CHG) as the vertical auto-flight system mode, and a climb speed of 250 kts. The crew intended to switch from LVL CHG mode to vertical navigation (VNAV) mode later during the climb, but inadvertently overlooked that selection.

Had the crew switched to VNAV mode as intended, the aircraft would have accelerated during the climb in accordance with a programmed speed schedule. In LVL CHG mode however, the aircraft climbed at a constant speed of 250 kts until passing about flight level (FL) 260, when the auto-flight system sequenced automatically to continue the climb at a constant Mach 0.62 (which was the Mach Number corresponding to 250 kts when the changeover occurred).

As climb then continued above FL 260 at a constant Mach 0.62, airspeed gradually reduced. The unintended vertical auto-flight mode and the gradual airspeed reduction went unnoticed by the crew until the aircraft was approaching FL 350, when a ‘buffet alert’ caution appeared on the Control Display Unit and the auto-flight system made a small reduction in aircraft pitch attitude. At that moment, the crew noted that the airspeed had reduced to near the top of the amber bar on the airspeed indicator, representing the aircraft minimum manoeuvre airspeed.

In responding to recognition of the minimum manoeuvre airspeed condition, the crew reduced the aircraft pitch attitude to the point that the aircraft entered a shallow descent. Soon after, the crew was able to establish an accelerated climb to the intended cruising level of FL 360. Recorded data indicates that that aircraft reached a minimum speed of 201 kts, about 6 kts below the minimum manoeuvre airspeed at that moment.

The occurrence highlights the importance of consistent attention to auto-flight system modes and aircraft energy state. Since this occurrence, the operator has introduced a procedure requiring the announcement of flight mode annunciation changes. The operator also included mode awareness briefings during a 2013 recurrent training program.

Aviation Short Investigations Bulletin - Issue 30

On 12 September 2011 a Vincent Airlines operated Raytheon Aircraft Company 1900D, registered VH-VAQ, departed Darwin Airport, Northern Territory on a local training flight. Onboard was a check captain, a check captain under training and a first officer (FO).

The purpose of the flight was to conduct a proficiency check in preparation for the FO to be checked to line operations. After take-off, at about 80 ft above ground level (AGL), the check captain announced, "simulating engine failure" and reduced the power on the left engine, setting above zero thrust. The FO recalled feeling pressure from the left rudder pedal under his foot and he instinctively pressed the left rudder pedal. He doesn't recall carrying out any actions to identify the failed engine.

The check captain observed that the aircraft had diverged left of centreline and was in about a 15-200 left level turn. The check captain took over the role of pilot flying and called "taking over". The FO replied, "handing over" and released the controls. The check captain applied right rudder, reduced the roll to the left and increased the power on the left engine while simultaneously reducing the power slightly on the right engine. The aircraft was established in a climb and reconfigured for a normal two-engine departure.

Following the event, the FO believed that the upward pressure he felt from the left rudder pedal was due to the normal operation of the rudder boost system deflecting the right rudder during the simulated engine failure.

The operator has actively pursued the establishment of a Beech 1900 simulator in the Australasian region. The operator is hopeful that an appropriate simulator will become available shortly and will endeavour to use the simulator for non-normal training.