The 117-strong fleet of Sikorsky S-92s has surpassed 250,000 flight hours. The medium twin entered service in 2004 and offshore operations have accounted for 90 percent of the air time since. The U.S. manufacturer claims mission reliability stands at 94 percent, while the fleet leader has logged 9,000 hours with Bristow. Eight offshore oil and gas ­transport companies fly 75 of the in-service S-92s.