Aerospace and Electronic Systems Magazine February 2018 - 33

Holland
Table 7.

ACKNOWLEDGEMENTS

Range of Possible MH370 Descent Rates at 00:19Z, 8
March 2014
Time Stamp

Min. Desc. Rate
(fpm)

Max. Desc. Rate
(fpm)

00:19:29Z

2,900

14,800

00:19:37Z

13,800

25,300

Min., minimum; Max., maximum; Desc., descent.

1,300 fpm per second. This equates to around 6.7 ms−2 or 0.68g,
where g denotes Earth's gravitational constant, which is approximately 9.8 ms−2. It is straightforward to see that other reasonable
methods of estimating the downward acceleration (such as taking
the difference between the two minimum descent rates or the two
maximum descent rates at 00:19:29Z and 00:19:37Z) would yield
similar acceleration values.

The author thanks his DST Group colleagues Dr. Neil Gordon,
Dr. Samuel Davey, Dr. Jason Williams, and Dr. Mark Rutten,
who worked alongside him as part of the MH370 Flight Path
Reconstruction Group, as well as Mr. Balachander Ramamurthy
for his support to the satellite data analysis. Special thanks go
to Dr. Gerald Bolding for both his support to the satellite data
analysis and his extensive efforts in reviewing and improving
this article. The author also thanks the many other members of
the MH370 Flight Path Reconstruction Group, which consisted of representatives from Inmarsat, Thales, Boeing, the U.S.
National Transportation Safety Board, the UK Air Accidents
Investigation Branch, Honeywell, SED, Square Peg Communications, and Panasonic. The group has been expertly led by
the ATSB.

REFERENCES
[1]

CONCLUSION
This article discussed all known factors that could have influenced
the BFOs associated with the last two SATCOM messages received
from MH370 at 00:19Z. Lower and upper bounds on its descent rate
at this time were then derived.14 The downward acceleration over
the 8-s interval between these two messages was found to be approximately 0.68g. The derived bounds and approximate downward
acceleration rate are consistent with simulations of an uncontrolled
descent near the seventh arc, as reported in [6]. This suggests that
9M-MRO should lie relatively close to the seventh BTO arc.
At the time of the submission of this paper, MH370 had not
been located. The search was in indefinite suspension pending
"credible new evidence pointing to a specific location for the
plane." Further efforts in data analysis and in drift modeling of
located MH370 debris have been conducted and reported (e.g.,
[6], [9], and [10]). The descent analysis from this paper was used
in [6] when considering the width of any potential future search
area. Some recent news reports have suggested a U.S. underwater
exploration firm named Ocean Infinity may soon be launching a
renewed search effort for MH370. Refer to the ATSB website [11]
and the general media for updates.

The conclusions regarding descent rate have been made taking
into account BFO noise bounds, all reasonably feasible ground
tracks and speeds, and possible OCXO warm-up drift. It has
been implicitly assumed that there were no otherwise-unknown
factors that could have affected the last two BFOs.

FEBRUARY 2018

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]
[10]
[11]

IEEE A&E SYSTEMS MAGAZINE

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