ANCHORAGE, Alaska—A contracted helicopter carrying guides and guests from a lodge on a heli-skiing trip in Alaska’s backcountry crashed, killing the pilot and four others, including the Czech Republic’s richest man. The only other person onboard was in serious condition but stable Sunday at an Anchorage hospital, Alaska State Troopers said. The five people killed in the Saturday accident were identified as Petr Kellner, 56, and Benjamin Larochaix, 50, both of the Czech Republic; Gregory Harms, 52, of Colorado; and two Alaska residents, Sean McMannany, 38, of Girdwood, and the pilot, Zachary Russel, 33, of Anchorage, troopers said Sunday. The five passengers included three guests and two guides from the Tordrillo Mountain Lodge, said company spokesperson Mary Ann Pruitt. Kellner was a businessman with a net worth over $17 billion, according to the Forbes 2020 list of the world’s richest people. Kellner owned a 98.93 percent stake in the PPF …