Another search for the missing Malaysia Airlines Flight 370 begins today, on 17 January 2018. On 10th January 2018 The New York Times has announced that the search for the missing aircraft will be resumed today by a private U.S. marine company Ocean Infinity and the company could earn up to $70 million if the aircraft will be found. Previously, Australian officials indefinitely suspended the unsuccessful search for Flight 370 after nearly three years. They concluded that they may have been looking too far south in the Indian Ocean.
As a physicists, I propose here one new idea (at least, I have never heard about it till now), that the pilots of the missing aircraft have tried to fly as long as possible for to make a relatively safe water landing without any rest fuel on the board. They could really try to reach Maldives, where it was still a dark night. We know from the cases of the US Airways Flight 1549, luckily ditched on the Hudson River in 2009, and the crashed Ethiopian Airlines Flight 961 in November 1996, how difficult is a water landing during day time. At night it should be still more difficult. But there could be another unlucky coincidence responsible for the (probable) crash of the Malaysian machine, trying to land on Indian Ocean's water that night.
The Earth's surface, including oceans, is not as smooth as that of a bowling ball. Our planet actually looks like a bumpy potato and its surface is called geoid. The gravity is non-uniform because of the unequal distribution of mass within the deep Earth. It is a well-known phenomenon. The geoid, rising wherever there is high gravity, and sinking where gravity is low, creates what is known as “geoid anomalies”. In Figure 1b of this publication we see the large region of deep depression in the Indian Ocean surface between Indian subcontinent and Australia. The depression exceeds sometimes 100 m.
If the landing-aircraft devices measuring the aircraft high above the ocean are not equipped with a proper gravimeter, it could cause an additional difficulty to land softly.
Maybe to look for the geoid anomalies on the probable course of the Flight 370 could help to find its final position.