Incident: Continental B752 near St. John s on Feb 28th 2010, flight control problems [UPDATE]

15.03.2010 - 23:09

A Continental Airlines Boeing 757-200, registration N18119 performing flight CO-1951 from Lajes (Portugal) to Newark,NJ (USA), was enroute at FL320 about 115nm south of St. John s,NL (Canada), when the crew declared emergency reporting flight control problems but did not request emergency services on standby and diverted to St. John s for a safe landing on runway 16 about 30 minutes later. The airplane had encountered another incident and diverted to Lajes the day earlier, see Incident: Continental B752 over Atlantic on Feb 27th 2010, avionics problems. The Canadian TSB reported on Mar 15th, that the crew received an air data computer AirSpeed Indicator disagreement warning, a rudder ratio warning, rudder speed trim message and elevator symmetry message. In addition, the autopilot attempted to trim the aircraft and disconnected, leaving the airplane with very sluggish control prompting the crew to declare emergency. The airplane descended and diverted to St. John s, where the airplane landed safely. The airplane had encountered a similiar problem the day before while over the Atlantic. The airline had dispatched 5 maintenance personnel to Lajes, who determined the right hand air data computer (ADC) was faulty. The right hand ADC was replaced and the airplane returned to service to be ferried back to Newark. After the diversion to St. John s it was found, that the replacement ADC was faulty, too. The ADC was again replaced and the airplane returned to service with no further incident. Both faulty ADCs were sent to the manufacturer Honeywell for detailed analysis. The operator suspected, that there was atmospheric ice present at cruise altitude and therefore replaced the right hand pitot tube as well. Read the article at http://avherald.com/h?articleB804ea5 Modify your subscription at http://avherald.com/h?login