A preliminary report released this week by the National Transportation Safety Board showed Dr. Clint Devin, the pilot whose plane crashed on top of Emerald Mountain, crossed the final approach for runway threshold about 600 feet lower than what the procedure required.

Devin, 46, died when his plane crashed into Emerald Mountain on Dec. 10. He was an orthopedic surgeon and partner at Steamboat Orthopaedic and Spine Institute, also practiced at Memorial Regional Health in Craig, and was revered for his work not just in the Yampa Valley, but across the nation.

The report does not go into the cause of the crash, but it describes how the plane failed to meet landing protocols.

According to the preliminary report, the plane was supposed to cross one of the waypoints at or above 9,700 feet altitude above sea level. At the next waypoint, about two miles from the Steamboat Springs Airport, Devin crossed at about 8,200 feet altitude above sea level.

Immediately after passing the second point, the airplane made a left turn and descended to an altitude of about 7,850 feet, the report continues. The airplane subsequently began to climb, and the last data point recorded at 6:49 p.m. indicated an altitude of about 8,125 feet about 3.5 miles north of the crash site.

The airplane first impacted Emerald Mountain about 8,172 feet on a heading of about 164 degrees, as evidenced by broken and cut tree branches. After the initial impact, the airplane bounced and came to rest about 8,216 feet. The plane sustained substantial damage to the fuselage, tail and both wings, the report states.

At the time of the accident, Steamboat indicated a cloud ceiling of 1,200 feet above ground level and limited visibility.

Because it is only a preliminary report, the review board noted that the report could contain errors. The preliminary report does not specify when the final report might be available.