Investigations are under way into a serious loss-of-control incident involving an Air Astana Embraer 190, during which the crew considered ditching in the sea.
It occurred during a post-maintenance ferry flight out of Lisbon aviation technical centre, where the jet had been undergoing C-check work with maintenance firm OGMA. The jet was bound for Almaty under the callsign KC1388 on 11 November.
Such was the severity of the situation that the crew advised Lisbon air traffic control that they were intending to ditch, and requested headings for the ocean.
Lisbon control told the crew that the ocean was 40nm away and that the closest body of water for a possible ditching was a river.
Shortly after departure, at around 13:33, the pilots issued a ‘Mayday’ before informing the Lisbon controller that the aircraft was experiencing a problem and requesting a return to the airport.
The controller initially gave a descent instruction to 2,500ft but the crew responded: “Negative.”
Provisional surveillance information transmitted from the jet indicates erratic altitude and speed data. The crew subsequently told the Lisbon controller that they had a “flight control problem” and were climbing to 10,000ft.
Air Astana says that initial indications point to “significant” roll-axis stability deviations, which took place in unfavourable weather conditions.
Some 10min after the distress call the crew stated that the aircraft was “completely unstable” and requested headings for a sea ditching – a request which was initially not understood by the controller, because the call was unreadable.
The aircraft, with three pilots and three engineers, was given vectors for a river. But the crew later informed the controller that, having gained manual control of the jet, they “plan to land on the sea, if possible”, stating that the sea would be a “better” option than the river, but adding that they needed “better weather”.
Air traffic control communications with the flight were archived by LiveATC.
Air Astana says that the crew, after some time, was able to take sufficient control of the aircraft and divert to Beja – landing only after a third approach to the airport, some 125km south-east of Lisbon, at about 15:36.
It says the captain has logged 5,340h including 4,000 on the Embraer 190, while the first officer has 3,000h and the second officer 2,000h.
Air Astana adds that the aircraft is still in Portugal and will only return to Kazakhstan once the authorities, manufacturer and airline are satisfied that the cause of the loss of control has been identified and remedied.
Portuguese air accident investigation authority GPIAAF identifies the aircraft as P4-KCJ, adding that it is conducting an inquiry and will detail the immediate facts of the "serious incident" on 13 November via an information bulletin.
Air Astana, which received the aircraft from the manufacturer in December 2013, says the investigation is being supported by Embraer, which has sent three specialists to the scene, while the airline is also sending two maintenance engineers and two pilots.
Maintenance firm OGMA, from whose Alverca base near Lisbon the aircraft departed, is co-operating with the inquiry. OGMA confirms it had been conducting maintenance work for the aircraft prior to its departure for Kazakhstan.
Its Alverca facility is some 15km from Lisbon airport. OGMA says the aircraft landed safely at Beja “with no material or physical damage", and adds that it is “working with the aeronautical authorities” to investigate the causes of the incident.