Experts from aircraft manufacturer Boeing are involved in an official analysis of the problem that caused a jet bound for Cayman Brac to be turned around mid-flight over the Christmas holidays.
Flight KX 105 from Grand Cayman to the Brac was turned back 10 minutes after take-off on Dec. 28 because of an issue with one of the aircraft’s flight control systems.
An inquiry has been launched.
Cayman Airways praised the pilot for his handling of the situation and characterized the decision to return to Grand Cayman as a “cautionary measure.” Emergency crews were on standby at the airport but they were not required and the plane landed safely.
An incident report, filed with the Civil Aviation Authority and seen by the Caymanian Compass, identifies the exact cause of the issue as a loose or snapped control cable which prevented the left side aileron from being used.
Ailerons are hinged movable surfaces located on the end of each wing and are normally used when the aircraft turns in flight.
An aviation expert who examined the details of the incident for the Compass, described the issues as “a serious problem but not insurmountable.”
David Kaminski-Morrow, Air Transport Editor at Flight International, said, “If the control cable to an aileron fails – perhaps because it has been stressed and frayed – it clearly presents a control difficulty to the pilot, one which might not immediately be understood.”
He said the aircraft would be unbalanced with a tendency to roll and the pilot would be required to compensate, using the rudder and the aileron on the opposite wing, to maintain level flight.
He said such incidents were “rare but not unheard of in older aircraft-types.” It is the first time a Cayman Airways flight has experienced an issue of this nature.
A spokesman for the airline said its pilots were trained to handle any abnormal situations that arose and that the pilot had maintained full control of the plane and had followed standard procedures by exercising “maximum caution” and returning to Grand Cayman.
He said the cable problem was fixed and the aircraft back in service within 24 hours. He said “preventative actions” had been implemented to ensure there was no recurrence of the issue on the entire fleet.
“Cayman Airways is currently working with the Civil Aviation Authority and Boeing Corporation to conduct a full analysis of the cause,” he added.
The spokesman acknowledged that the left aileron had become inoperative during the flight but said this had “minimal impact” on the aircraft’s controllability.
“Whilst the left aileron became inoperative, the remaining roll control devices and rudder were fully functional, ensuring that the pilots were able to maintain complete control over the aircraft. This is actually a design feature from the manufacturer to ensure built in redundancy …
“Our pilot’s proficiency, combined with the aircraft’s built-in redundancies ensured the complete safety of our passengers and operations.”
The incident report indicates that the plane was approaching 11,000 feet when a “bang and jolt” was heard by the captain.
It states that the aircraft started to turn to the left, forcing the captain to disconnect the autopilot and use the right aileron to maintain level flight.
It says the crew were unable to positively identify the exact cause of the problem and declared an emergency and returned to Grand Cayman. An inspection of the plane later identified the cause.
“The left aileron down cable was found to have failed and was hanging loosely. This condition rendered the left aileron inoperative with the system tension removed on the side,” the report states.