Tuesday, March 25, 2014

How can we locate MH370 in the Southern Indian Ocean?

Tragically, Malaysians Airlines Flight MH370 went down with 239 people aboard on 8 March in the Southern Indian Ocean. We have to find the "Black Box" flight recorder to find out what happened, and we have until 5th April to locate the is before the ultrasonic signal from its Underwater Locator Beacon dies.

Pundits are saying that the recorder may therefore never be found. They may be wrong.

It looks as if wreckage from MH370 has been found around the area 95 degrees East and 43 South.

It will be possible to calculate, from the position of the wreckage, using data on currents and windspeed and direction over the last 18 days, the location from where the wreckage has drifted, that is, the impact zone. This gives the area to be searched, although the uncertainties will be great, so the search area may cover hundreds or even thousands of square kilometers.

The black box and other non-floating parts of the aircraft may be lying at a depth of up to 5000 metres (5 kilometers, three miles).

Now the Underwater Locator Beacon ("pinger") can be detected between 1 and 9 km away, depending on type. It sends out an ultrasound signal, and a submersible that can detect the signal is already on its way to the search area. Hopefully more than one detector will be sent, but given the vast area to be searched and the small time available, it will need a great deal of luck for the flight recorder to be found by its pinger.

After the 5th of April, they will tend to rely on AUV's, Autonomous Underwater Vehicles to film the sea floor for clues. Sonar imagers were used in the cals of AF447. Either way, this may take months. The search for AF447 took two years.

But there may be another way to search, one that can be started now, and may be able to "see" further than AUVs: metal detector technology.

Metal objects affect the magnetic fields around them, and this distortion can be picked up. Early naval mind detectors relied on this to locate mines. Now although the game has moved on somewhat, and although the modern idea is to try to trigger the mine to explode, the physical principle remains. Modern physical instruments are exquisitely sensitive, and there may be magnetic detection technologies ready to deploy to the field right now.

Given also that it may take years to find the wreckage using visual and sonar methods, there is scope for experimental and prototype magnetic detection modalities to be deployed. After all, there is enough space to search, so provided they do not get in each other's way, a search strategy that is open to all sensible helpers would be the best way forward. What is needed is an open minded attitude from the authorities co-ordinating the search.

In short, they need to concentrate on finding the metallic parts of the aircraft, because these will lead to the flight recorder.

4 comments:

Hengist said...

It was astonishing that they recovered the flight recorder from AF447. But in that instance they found bits of the aircraft within a few days so they knew (very) roughly where the hull would be. MH370 is very different, until they find a piece of wreckage the only thing to go is the (inspired) Inmarsat assessment. It's a massive search area in portion of the ocean that hasn't even been charted

Richard Lawson said...

Hi Hengist,
I hope they are calculating the impact area already, on the assumption that the stuff they are seeing is MH370. It is going to be a massive search area, which is why 1-2 ping detectors are totally inadequate. But a fleet of sensitive metal detectors would very much improve the chances of an early discovery.

R

Richard Lawson said...

Hi Hengist,
I hope they are calculating the impact area already, on the assumption that the stuff they are seeing is MH370. It is going to be a massive search area, which is why 1-2 ping detectors are totally inadequate. But a fleet of sensitive metal detectors would very much improve the chances of an early discovery.

R

hengist mcstone said...

Yes. I like your idea of metal detection. They reckon they've spotted 122 objects from satellite, I'm skeptical though because there's a lot of trash in the sea anyway. It would I think be unusual not to spot floating stuff over a wide enough area. My guess is this story will remain a great mystery.