The captain and first officer allegedly began feeling unwell soon after Glasgow-bound flight took off on 7 January 2011.
The Daily Mail reported some passengers hearing the pilots panicked messages coming over the PA. One passenger allegedly told a professional pilots website: “A very abrupt and panicked message came over the PA from the pilot.”
The passenger said he then saw flight attendants rush to the cockpit with oxygen cylinders and the plane was soon heading back to Heathrow "at great speed". Members of the cabin crew told passengers the plans was experiencing technical difficulties but the plane was met by paramedics, fire crews and engineers when it landed.
In a statement given by British Airways, it was confirmed that both pilots on the flight felt unwell and followed procedure by putting on oxygen masks and aborting the flight.
The incident is being investigated by British aviation authorities.
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