Safety Investigation Report 2018:1 Factual Information/1.6/1.6.9 Aircraft Performance
SAFETY INVESTIGATION REPORT MH370 (9M-MRO)
1.6.9 Aircraft Performance
The detailed Boeing Performance analysis of the aircraft is provided in Appendix 1.6E. This section summarises the aircraft performance and range capability of MH370.
The following data were available to help analyse the possible flight paths of the aircraft: ACARS data, radar data, and satellite data. Wind data were incorporated along the paths to determine the true airspeed which was incorporated into the performance fuel burn and range analysis.
The ACARS data provided the quantity of fuel on board after approximately 25 minutes of flight following take-off from KUL.
The radar data provided information about the flight path and ground speed after the last ACARS transmission and captured the left turn off of the scheduled route until the data ended over the Straits of Malacca. The analysis of the radar data allowed for an estimation of the fuel burn during that portion of the flight. However, that estimation was built on many assumptions, including flying at constant altitude and constant airspeed during each flight segment.
The satellite data provided evidence that the satellite was in communication with the aircraft until the last transmission at time 0019:29.42 UTC, approximately 7 hours and 37 minutes after take-off from KUL. Refer to Section 1.9.5.
The performance range capability of the aircraft, along with the satellite data, allowed for the creation of multiple flight path profiles that demonstrate that the aircraft had the range capability to reach the 7th Arc10.
Many assumptions were also made during the flight path profile creation, including but not limited to, constant altitude and constant speed from Arc 1 to Arc 7, with the restriction that there were no course changes between the arcs. Additional analyses were conducted in Boeing and MAS simulators that continued the analysis after fuel exhaustion and assumed no intervention in the cockpit.
The results of the simulator session showed that the aircraft would roll gently to the left due to residual rudder deflection commanded by the Thrust Asymmetry Compensation (TAC) with the end of flight occurring within a 100 nm2 box that extended 10 nm beyond fuel exhaustion and 10 nm to the left of the flight path. The maximum range after dual engine flame-out would have been achieved through driftdown, with manual control keeping the aircraft in wings level flight, and would extend the range of the aircraft by approximately 120 nm beyond the location of the dual engine flame-out.
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10Arcs - Lines created along the earth representing a set of possible aircraft positions at the time of satellite communication based on Burst Timing Offset (BTO). Refer to Appendix 1.6E for further details.