The unprecedented search effort for Malaysian Airlines flight 370 has yet to achieve its main goal of locating the vanished aircraft and the 227 persons on board. However, it has served as an endurance test of sorts for offshore surveying systems such as the autonomous underwater vehicle (AUV), which just a couple of years ago was considered an emerging technology with a small track record. Edward Saade, president of the ocean surveying firm Fugro Pelagos, the company contracted by the Australian government to carry out much of the search operation, said he knows of no other commercial project where AUVs have been successfully deployed for such an extensive period of time.
Speaking at the 2016 Offshore Technology Conference in Houston, Saade said that to cover large swaths of subsea terrain as quickly as possible and capture high-resolution data, Fugro first deployed vessels equipped with conventional deep-tow side scanning sonar. Then starting in January of last year, the AUV vessel was deployed from Perth.
“The purpose of the AUV was to try and get into all those areas that turned out to be blocked in the side-scan operation, either by the steep slopes or other types of data anomalies,” Saade said. “We would preprogram the AUV, launch it and it would do its thing for about 24–28 hours and very effectively fill in all the gaps.”
In the future, he suggested that it may be possible to use a larger number of AUVs and deploy them from multiple points to carry out such large surveys. But the limits of today’s AUV technology meant covering the 120,000 km3 of Indian Ocean that make up the search area—roughly the size of New Zealand—would have taken about a decade.
“I have completely bought in to the AUV approach,” Saade said. “So going to a deep-tow approach almost seemed like a step backward, but it turned out to be the exact right approach for something on this massive scale.”
The AUV that Fugro used in the project is the Kongsberg-Hugin 100 model, which was selected because of its technological abilities, and since there are many in production, replacements or spare parts would be readily available. The sensors on both the AUV and the deep-tow units were the same, which allowed the data to be seamlessly integrated.
Saade discussed many other details of the search effort which has taken place in one of the most remote and unexplored areas of the planet.
He said the initial seabed survey revealed that the actual water depths in some areas were more than a mile shallower than what existing ocean maps suggested. This proved to be a critical data point in helping Fugro select which sensors to use and it also meant the operations would be a little easier to perform.
When investigators turned to Australian satellite operators to look for any sign that the aircraft’s communications system sent locating information up to space, the companies all said that they use the area in question for downtime and maintenance.
And despite the “hellacious seas” that are common during the winter months in this part of the Indian Ocean, Saade noted that the project has incurred very little downtime, most of which was due to crew illnesses and not equipment failure.
