Casper-Natrona County

The pilot obtained a weather briefing, filed an IFR flight plan, and departed on a nonscheduled domestic cargo flight, carrying 270 pounds of freight. The flight proceeded uneventfully until it was established on the VOR/DME-C approach. Radar data indicates that after turning inbound towards the VORTAC from the DME arc, the airplane began its descent from 10,600 feet to the VOR crossing altitude of 9,200 feet. Enlargement of the radar track showed the airplane correcting slightly to the left as it proceeded inbound to the VORTAC at 9,400 feet. Shortly thereafter, aircraft track and altitude deviated 0.75 miles northwest and 9,700 feet, 0.5 miles southeast and 9,600 feet, and 0.5 miles northwest and 9,400 feet before disappearing from radar. Witnesses said the weather at the time of the accident was 600 foot overcast, 1.5 miles visibility in "misting" rain that became "almost slushy on the ground," and a temperature of 36 degrees Fahrenheit. One weather study indicated "an icing potential greater than 50% and visible moisture" in the accident area. Another report said "icing conditions were likely present in the area of the accident." The airplane was equipped and certified for flight into known icing conditions. The wreckage was found in a closely area. There was no evidence of pre-impact airframe, engine, or propeller malfunction/failure. The pilot was properly certificated, but his flight time in aircraft make/model was only 38 hours. He had previously recorded 16 icing encounters, totaling 11.2 hours in actual meteorological conditions. He recorded no ice encounters and only 1.0 hour of simulated (hooded) instrument time in the Cessna 208. Microscopic examination of annunciator light bulbs revealed the GENERATOR OFF light was illuminated. This condition indicates a generator disconnection due to a line surge, tripped circuit breaker, or inadvertent switch operation. The operator's chief pilot agreed, noting that one of the items on the Before Landing Checklist requires the IGNITION SWITCH be placed in the ON position. The START SWITCH is located next to the IGNITION SWITCH. Inadvertently moving the START SWITCH to the ON position would cause the generator to disconnect and the GENERATOR OFF annunciator light to illuminate. He said this would be distracting to the pilot.

The aircraft was on an air ambulance (EMS) flight and was cleared for the ILS runway 08 approach at Casper, WY. Radar data showed the aircraft tracking and descending normally on the DME arc, until it was below radar coverage for the area. Subsequently, it collided with the top of a ridge, along the localizer centerline, before reaching the outer marker, about 8 miles from the airport. Elevation of the crash site was about 5,800 feet; minimum descent altitude before intercepting the ILS glide slope was 7,100 feet; crossing altitude at the outer marker was 6,700 feet. All four occupants were killed, a patient, two doctors and a pilot.

Before departing, the pilot obtained a weather briefing and was advised of a sigmet which forecasted severe turbulence below 18,000 feet, strong up/downdrafts, strong surface winds and wind shear near mountains and in passes. He took off with full fuel tanks and approximately 400 lbs of cargo on board. ARTCC reported that the en route portion of the flight was handled routinely. During arrival, the pilot contacted the airport unicom for a landing advisory. A King Air pilot was arriving at about the same time and asked the Aerostar pilot if he was making a full stop. The Aerostar pilot replied that he was. The King Air pilot lost sight of the Aerostar and began a 360° turn. He asked the Aerostar pilot to advise of his position, and shortly thereafter, the Aerostar pilot transmitted three mayday calls. Reportedly, the aircraft nosed up and went into a steep right bank just before impact. No preimpact mechanical failure/malfunction was found. There was evidence that most of the cargo was in the baggage compartment (limited to 240 lbs) and could have moved the CofG well beyond the aft limit. Elevator trim found full nose down. The pilot, sole on board, was killed.

Shortly after takeoff from Casper-Natrona County Airport, while climbing, the single engine airplane struck trees and crash landed in a field. The pilot, sole on board, was killed.

Western Air Lines flight 470 to Casper and Minneapolis departed Denver at 07:03 in the morning. The airplane, on an IFR flight plan, climbed to its cruising altitude of FL220. At 07:36, following a descent to 12,000 feet, the flight crew contacted Casper approach control and advised that the flight was about 12 miles south of the Evansville Intersection. At that time, the controller cleared the flight to use the localizer back course approach for runway 25, to circle to runway 3, or to land straight in. The weather reported to the crew indicated poor visibility with light snow falling and wind 040° at 9 knots. One minute later, the approach controller advised that "runway 7/25 has been plowed. There's about a 1/4-inch of powder snow on it. Braking action reported, Convair 580, as poor. Runway 3/21 is being plowed at this time." At 07:51, Flight 470 reported at the Henning Intersection and was cleared to contact the Casper Tower. The tower controller cleared the flight to land on runway 25 and gave the wind as 030° at 8 knots. The flight was also advised by the controller that a disabled snow blower was "just west of the intersection runway 21, left side runway 25, on the edge ...." At 07:41:42, the first officer called out "thousand to go to the field." At 07:42:09, the first officer called "approaching minimums," and 12 seconds later, he called "just about at minimums." The aircraft then flew level for a few moments a t the minimum descent altitude (MDA). At 07:42:25, the first officer called the runway in sight directly below the aircraft. At that time airspeed was 150 knots and the flaps were at 25°. The first office then set the flaps at 30° as the captain initiated the final descent. The aircraft crossed the threshold at reference speed +15 knots. The aircraft touched down 2,375 feet from the departure end of the runway, about 6,306 feet from the approach end of the runway. The aircraft went off the departure end of the runway to the right of the centerline. After striking several metal stanchions in the first row of terminal bar lights, which were located 200 feet off the end of the runway, the aircraft struck a shallow irrigation ditch 280 feet off the runway end. The aircraft veered farther to the right and stopped about 800 feet beyond the departure end of the runway.