The search for the Boeing 777 that went missing above the Indian Ocean early March is in its second phase. A towed sensor produces high-resolution images.
The missing flight MH370 that took off from Kuala Lumpur with destination Bejing is a modern-day mystery. It never arrived in China, but instead it made an 180-degree turn and headed south-west. Based to the last Inmarsat communications, the Malaysian government has identified a 60,000 km2 area 2,000 km southwest of Australia as the probable crash site by. All 227 passengers and 12 crew members are missing.
The Australian Transport Safety Bureau (ATSB) has ordered an underwater search for the wreckage that started October 5, 2014 and will last up to a year at a cost of about 40 million euros.
Alumnus Rob Luijnenburg from Fugro visited TU Delft to discuss about the ongoing operation on 20 November. Fugro is a specialist in soil research, which they perform by truck, aircraft, vessels and unmanned submarines.
Crash siteCrash site
Crash site
Luijnenbrug reminded the large audience in the lecture hall that missing planes are less rare than assumed. The disappearance of an Air France flight AF447 above the Atlantic Ocean in 1997 is comparable with the MH370. The wreckage, found at 1,500 metres depth, shows what the searchers are up against: no intact plane, but debris scattered over 500 metres with engines and landing gear as the largest and most identifiable pieces.
Zooming inZooming in
Zooming in
The search, coordinated by the ATSB, consists of three phases with increasing resolution. In the first phase, four 60 metre ships with echo sounders crisscrossed the designated strip to produce a map of the seafloor at about 7,000 metres deep. During that phase, a survey has revealed two new volcanoes on the seabed and numerous improvements over the default map. Existing depth maps of the open seas are based on satellite measurements of sea surface elevation. The mass of mountains on the sea floor makes the sea surface bulge, just enough to be detectable from satellites.
During the second phase, a towed sonar device at the end of a 10-kilometre cable behind the ship swims 150 metres above the seabed. The resolution of its sonar is 10 – 50 centimeters, which makes Luijnenbrug say with confidence ‘if it’s there, we will find it.’ He reports that 7,000 km2 has been covered so far – about a quarter of the area that the ATSB wants to cover in detail.
In the third phase, a small autonomous vehicle will be launched from one of the ships to scan interesting areas with centimeter-resolution. Its batteries allow trips up to three days during which the ten million dollar device remains in contact with the mother ship by acoustic link. Launching the submarine and getting it back on board requires calm seas, which is not the typical state of this part of the Indian Ocean known as the roaring forties.
Ultimately, the goal is to identify and recapture the black box – the only record of what happened to the unfortunate flight. For that to happen, the current second phase must produce evidence for debris on the deep sea floor. If it doesn’t, the plane must have crashed outside of the calculated area.
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