In February 2010, a cargo door came unlatched on an airborne Alpine Air Express Beech 99 carrying mail from Billings, to Kalispell, Montana, at about 1:30 a.m. The plane was about north of Lewistown, Montana, when the pilot noted a light on the instrument panel had come on, indicating the door was unlatched. Because there was about of mail cargo in between the pilot and the door, he couldn’t close it. Because the door is located below the plane’s airstream, even when open it wouldn’t compromise the ability to fly and land the plane.