Luxury jet makers battle over lucrative spy plane niche By Allison Lampert and Tim Hepher Reuters MONTREAL/PARIS (Reuters) - Last month, a ghostly grey business jet took off from central Sweden and headed across the Baltic on a routine spying mission. The converted Gulfstream, caught on a tracking website, was flown by the Swedish Air Force and patrolled an area thick with Russian radar signals off the militarised coast of Kaliningrad. Apart from a couple of unobtrusive bulges underneath, Sweden's two Gulfstream-based S102B Korpen spy planes look like any other sleek corporate jet. But inside, the Swedish jets and a growing fleet of newer corporate aircraft contain the eyes and ears of a relentless intelligence war.