Malaysia Airlines Flight 370

==== Inferences ====
A few inferences can be made from the satellite communications. The first is that the aircraft remained operational until at least 08:19 MYT—seven hours after final contact was made with air traffic control over the South China Sea. The varying burst frequency offset (BFO) values indicate the aircraft was moving at speed. The aircraft's SDU needs location and track information to keep its antenna pointed towards the satellite, so it can also be inferred that the aircraft's navigation system was operational.<ref name=JN-Inmarsat />{{rp|4}}

Since the aircraft did not respond to a ping at 09:15, it can be concluded that at some point between 08:19 and 09:15, the aircraft lost the ability to communicate with the ground station.<ref name="Inmarsat(26 March)"/><ref name=Fox-Inmarsat /><ref name="myDCA_20140325" /> The log-on message sent from the aircraft at 08:19:29 was "log-on request"; there are only a few reasons the SDU would transmit this request, such as a power interruption, software failure, loss of critical systems providing input to the SDU, or a loss of the link due to the aircraft's [[:wiktionary:aircraft attitude|attitude]]<!-- ATTitude NOT ALTitude. This has been changed many times. Because there is no concise Wikipedia article/section to point to, a link to the definition on Wiktionary is appropriate -->.<ref name=ATSB />{{rp|22}} Investigators consider the most likely reason to be that it was sent during power-up after an electrical outage.

At 08:19, the aircraft had been airborne for 7&nbsp;hours and 38&nbsp;minutes; the typical Kuala Lumpur-Beijing flight is 5{{frac|1|2}}&nbsp;hours, so [[fuel starvation|fuel exhaustion]] was likely.<ref name=ATSB />{{Rp|33}}<ref>{{cite web|title=Considerations on defining the search area&nbsp;– MH370|url=http://www.atsb.gov.au/publications/2014/considerations-on-defining-the-search-area-mh370.aspx|publisher=ATSB&nbsp;– Australian Transport Safety Bureau|access-date=28 May 2014|archive-date=26 May 2014|archive-url=https://web.archive.org/web/20140526210049/http://www.atsb.gov.au/publications/2014/considerations-on-defining-the-search-area-mh370.aspx|url-status=dead}}</ref> In the event of fuel exhaustion and engine flame-out, which would eliminate power to the SDU, the aircraft's [[ram air turbine]] (RAT) would deploy, providing power to some instruments and flight controls, including the SDU.<ref name=ATSB />{{Rp|33}} Approximately 90&nbsp;seconds after the 02:25 handshake—also a log-on request—communications from the aircraft's [[in-flight entertainment]] system were recorded in the ground station log. Similar messages would be expected following the 08:19 handshake, but none were received, supporting the fuel-exhaustion scenario.<ref name=ATSB />{{rp|22}}