The search for MH370 and ocean surface drift
Executive summary - Report II
This report explores the possibility that an improved ability to simulate the path taken by the flaperon across the Indian Ocean might yield an improved estimate of the location of the remains of the aircraft on the sea floor.
Our earlier field testing of replicas of the flaperon was unable to confirm numerical predictions by the Direction Generale de L’Armement (DGA) that the flaperon drifted left of the wind. Field testing of a genuine Boeing 777 flaperon cut down to match photographs of 9M-MRO’s flaperon has now largely confirmed the DGA predictions, at least with respect to drift angle. The impact of this information on simulated trajectories across the Indian Ocean is that the July 2015 arrival time at La Reunion is now very easy to explain.
This new information does not change our earlier estimate of the most probable location of the aircraft. It does, however, increase our confidence in that estimate, so we are now even more confident that the aircraft is within the new search area identified and recommended in the MH370 First Principles Review (ATSB 2016).
The proposed new search area has been determined by combining many lines of evidence, the strongest being that the descent began close to the SatCom 7th arc. The following evidence from drift modelling helps indicate where along the 7th arc the aircraft impacted the sea surface:
- The July 2015 arrival date of the flaperon at La Reunion island is consistent with impact occurring between latitudes 40°S and 30.5°S.
- Arrival off Africa of other debris exclusively after December 2015 favours impact latitudes south of 32°S, as does the failure of the 40-day aerial search off Western Australia to find any floating debris.
- Absence of debris findings on Australian shores is only consistent with a few impact latitudes – the region near 35°S is the only one that is also consistent with other factors.
The new search area, near 35°S, comprises thin strips either side of the previously-searched strip close to the 7th arc. If the aircraft is not found there, then the rest of the search area is still likely to contain the plane. The available evidence suggests that all other regions are unlikely.