PILOTS were forced to use oxygen masks for an emergency descent as an airliner lost cabin pressure on a Dublin flight.
The 23 passengers and four crew on board the FlyBe aircraft escaped serious injury, but several passengers complained of sore ears, said an air accident report.
The twin-engine DHC Dash 8 left Southampton for Dublin on January 5 and started its climb to 24,000ft when the cabin lost pressure.
The pilot tried switching the plane's pressurisation to manual and then back to auto, but there was no response.
"Both flight crew immediately donned oxygen masks," the report said.
The co-pilot declared a mayday and the pilot put the plane into an emergency descent.
The plane levelled at 10,000ft, and the mayday was downgraded to a level signalling urgency but no immediate threat to life.
The pilot then turned the plane around and returned to Southampton.
Both cabin crew members told investigators they had been serving food and drinks to passengers when they noticed that sandwich packets and coffee cup foils were beginning to burst.
One said: "As I was walking to the rear of the galley my ears were popping and I felt short of breath, my legs felt weak."
Both of the cabin crew members used oxygen bottles "to regain composure and to refocus," the report said.
One said: "I called the flight deck but there was no answer and I was worried that they were okay."
Soon afterwards, an announcement came from the flight deck over the PA system saying "This is the captain. Emergency descent is now complete."
The cabin crew reported that several passengers complained of sore ears.
The accident report said a faulty valve was the likely cause of the depressurisation.
After the incident, investigators tested the passenger address and interphone system to find out why the cabin crew could not contact the pilot, but it was found to be working properly.
Analysis of the cockpit voice recorder revealed that the audible call bell could be heard in the cockpit but that "neither member of the flight crew reacted to it".
"The call bell sounded shortly after the flight crew opted to use oxygen masks, during a period when they were busy trying to establish initial communications with each other," the report added.