A part of the wreckage of Malaysia Airlines Flight MH17 is pictured in a field at the crash site, near the village of Hrabove, in Ukraine's Donetsk region, on July 20, 2014. Picture: Maxim Zmeyev

Toulouse, France - The downing of Malaysia Air Flight 17 over Ukraine has thrust a plane-tracking application into the limelight as more people study global flight paths that previously only drew aviation enthusiasts and professionals.

The Flightradar24 app, which comes for free or as a paid service with more content, tops the charts of Apple's app store in Britain, Germany and the Netherlands, the country that lost the most people in the crash. A 50-fold traffice increase to the company's website has choked server capacity, forcing it to restrain some services to increase bandwidth.

“We've had several surges in app sales since the Iceland ash cloud, but this is by far the biggest,” said Frederik Lindahl, the 37 year-old Flightradar24 chief executive officer, who runs the company out of Stockholm.

The growing fascination with flightpaths stems in part from the dearth of reliable information surrounding the crash, caused most likely by a missile strike over eastern Ukraine.

Flightradar24 data show that while the airspace was deemed safe by authorities at Flight 17's cruising altitude, some airlines had avoided traversing the region even before it was closed following the incident, while other planes were in close pursuit of the Malaysian Boeing Co. 777, which was carrying 298 people.

Flightradar24's data reveals that the airspace over Ukraine was a popular route before the downing, with MH17 having flown the same path five days in the prior week. In that time, some 820 flights traversed eastern Ukraine, with two — flown by Singapore Airlines and Air India within 16 miles of the Malaysian jet when it was blown up.

With the air space over eastern Ukraine now closed, the app shows a string of aircraft snaking through Turkey and Russian territory adjacent to Ukraine on their path between Europe, the Middle East and Asia.

Lindahl and his staff that comprises 12 people in Stockholm compile the flightpaths using data gleaned from automatic dependent surveillance-broadcast technology, or ADS-B, which picks up an aircraft location.

The company relies on a network of more than 4 000 receivers, a contraption the shape a small box that can be positioned on an house roof to transmit data.

Flightradar24 has shipped several ADS-B sets as far as Greenland and is scouring uncovered spots around the globe, including Ilha Fernando de Noronha, a tiny island on the coast of Brazil. Lindahl said his company sends out about 50 receivers each week, at a total cost per shipment of $700 (about R7 000).

“That's where we spend most of our focus, to increase the network,” he said. “It's plug and play. There's no external computer involved, it just needs power and uses very little power, and Internet access.”

Flightradar24 started more as a hobby in 2006 when two Swedish aviation enthusiasts created a network of ADS-B receivers in northern and central Europe, Lindahl said. Two years later, the team made the system available to anyone with the right device to upload data.

For now, Flightradar24 remains self-funded, according to the CEO. It's app costs 1.99 pounds in Britain, home to London Heathrow airport, Europe's busiest. Lindahl said he gets regular calls from major venture-capital funds and is happy to entertain “polite” discussions about their interest.

“Who knows?” he said. “The situation could change. We might come across an idea that would require more capital and then we'd look into it.”

The app, whose frequent users include airlines, planemakers, and airports, has seen surges in interest before, including when an ash cloud emanating from a volcano in Iceland grounded flights across Europe in 2010, and after Malaysian Air Flight 370 mysteriously vanished in April. Yet the fascination with flight paths hit a new peak after MH17's downing.

“After we saw MH370 disappear, I thought it would be hard to beat, but this beats by quite a wide margin,” Lindahl said. - Bloomberg News

* Weiss reported from Frankfurt, Germany. Kari Lundgren contributed from London.