Aircraft control issues have come into the sights of the Australian Transport Safety Bureau (ATSB) after a rise in reported incidents in the six months to June 2014.
An ATSB report titled “Emerging trends in Australian aviation safety” published on Thursday showed aircraft control issues among the nation’s airlines rose to almost eight occurrences per 100,000 departures.
While these were typically low frequency incidents, aircraft control issues have been on the rise from January to June 2014, the ATSB report said.
The ATSB said 10 of the 16 total incidents reported were from one single airline, while the Fokker 100 featured in five of the 16 occurrences.
The regulator said the Fokker 100 was “overrepresented when considering its fleet size and activity”.
“Occurrences involving Fokker 100 aircraft were uncommanded pitch down events during cruise or descent, or uncommanded forward and aft movement of the control column while the autopilot was engaged,” the ATSB report said.
“In most of these cases, the flight crew disengaged the autopilot entirely, or deselected and reselected the secondary autopilot system. In three cases, engineers replaced the affected system autopilot servos and in one case, replaced an elevator trim servo following the occurrence.”
The ATSB said most of the other control issues were “isolated events resulting in incorrect aircraft configuration warnings”.
Meanwhile, the regulator said its investigation into independent visual approaches (IVA) into Sydney Airport was expected to be completed in late 2014.
Sydney Airport featured in 12 of the 28 incidents involving airborne collision alert warnings over the past six months, the ATSB said, with all but two involving approaches to the 34L/R runway.
“Further investigation by the ATSB has found that IVAs at Sydney Airport have contributed to most of the rise seen in this type of occurrence over the last two years,” the ATSB said.
“No particular operators or aircraft types stood out, and most were routine alerts that were not associated with a separation loss. None resulted in a missed approach or go-around.”