I mentioned the ADIRU in another post.. This airplane (MRG) had an issue a while ago where they had zero authority on the control surfaces while it was in AP. Not saying MRO had this problem, but it's a little weird they were at similar cruising altitudes.
On 1 August 2005 a serious incident involving
Malaysia Airlines Flight 124, occurred when a
Boeing 777-2H6ER (9M-MRG) flying from
Perth to
Kuala Lumpur also involved an ADIRU fault resulting in uncommanded manoeuvres by the aircraft acting on false indications.
[14] In that incident the incorrect data impacted all
planes of movement while the aircraft was climbing through 38,000 feet (11,600 m). The aircraft pitched up and climbed to around 41,000 feet (12,500 m), with the stall warning activated. The pilots recovered the aircraft with the autopilot disengaged and requested a return to Perth. During the return to Perth, both the left and right autopilots were briefly activated by the crew, but in both instances the aircraft pitched down and banked to the right. The aircraft was flown manually for the remainder of the flight and landed safely in Perth. There were no injuries and no damage to the aircraft. The ATSB found that the main probable cause of this incident was a latent software error which allowed the ADIRU to use data from a failed
accelerometer.
[15]
The US
Federal Aviation Administration issued Emergency Airworthiness Directive (AD) 2005-18-51 requiring all 777 operators to install upgraded software to resolve the error.
[16]