I don't have Lear 55 data with me and I'm too lazy to go in the other room and pull up Lear 35 data or charts; the Lear 55 uses Lear 35 gear and brakes, and weights about 3,000 more at gross weight. Otherwise very similar speeds and performance, though the 55 goes higher.

The 55 operators advise 2,800' landing distance, without specific qualification.

Personally, having flown in and out of Livingston and Bozeman, I'd have preferred Bozeman, which isn't far away. 1.67 landing distance becomes an issue for dispatch purposes, but not for operational purposes; one doesn't need to see that value before starting an approach. For dispatch purposes, under Part 135, the airplane must be able to land in 60% of the available dry runway, or specifically, 1.67 times the landing distance of the airplane must be equal to, or less than the available runway landing distance. For dispatch purposes, the airplane landing distance data would have needed to show that the airplane coiuld land and be stopped (after passing a threshol 50' obstacle) by 3,420;. If 1.67 times the manufacturer performance data showed a landing distance of that value or less under forecast conditions, then the airplane was legal, on a dry runway.

No doubt that information, or some approximation thereof, will be available with the accident report.