Last week’s stock market tumble put a chokehold on Inmarsat’s Swift64 satellite ISDN service as business jet passengers, particularly those on the U.S. East Coast, scrambled for their laptops and, perhaps predictably, brought the network to a grinding halt. As demand for the service continues to skyrocket, Swift64 is having trouble handling data traffic in the U.S. and Europe at peak times, especially on weekday afternoons. Speaking at a Satcom Direct customer conference today in Melbourne, Fla., Inmarsat head of aeronautical marketing Lars Ringertz acknowledged the problem and said the satellite maker is exploring ways to allocate extra spectrum in affected areas and developing equipment upgrades. “Nobody expected this kind of growth,” Ringertz said of the Swift64 service, adding that the start of the higher bandwidth SwiftBroadband service later this year should help alleviate congestion. Meanwhile, Inmarsat plans to implement a so-called “closed user group” that would guarantee network access for certain high-bandwidth users at peak times.