United States of America

On December 10, 1946, six Curtis Commando R5C transport planes carrying more than 200 U.S. Marines leave San Diego en route to Seattle. The aircraft, flying entirely by instruments at an altitude of 9,000 feet, encounter heavy weather over southwest Washington. Four turn back, landing at the Portland Airport; one manages to land safely in Seattle, but the sixth plane, carrying 32 Marines, vanishes. Search-and-rescue aircraft, hampered by continuing bad weather, are unable to fly for a week and ground searches prove fruitless. After two weeks, the search for the missing aircraft is suspended. The Navy determines that the aircraft was blown off course by high winds and flew into the side of Mount Rainier (14,410 feet). In July 1947, a ranger at Mount Rainier National Park spots wreckage on South Tahoma Glacier. Search parties examine the debris and confirm that it came from the missing plane. Four weeks later, the bodies are found high on the face of the glacier, but extremely hazardous conditions force authorities to abandon plans to remove them for burial. The 32 U.S. Marines remain entombed forever on Mount Rainier. In 1946, it was the worst accident, in numbers killed aboard an aircraft, in United States aviation history and remains Mount Rainier’s greatest tragedy.
Crew:
Maj Robert V. Reilly, pilot,
Lt Col Alben C. Robertson, copilot,
M/Sgt Wallace J. Slonina, crew chief.
Passengers:
M/Sgt Charles F. Criswell,
Pvt Duane R. Abbott,
Pvt Robert A. Anderson,
Pvt Joe E. Bainter,
Pvt Leslie R. Simmons Jr.,
Pvt Harry K. Skinner,
Pvt Lawrence E. Smith,
Pvt Buddy E. Snelling,
Pvt Bobby J. Stafford,
Pvt William D. St. Clair,
Pvt Walter J. Stewart,
Pvt John C. Stone,
Pvt Albert H. Stubblefield,
Pvt William R. Sullivan,
Pvt Chester E. Taube,
Pvt Harry L. Thompson Jr.,
Pvt Duane S. Thornton,
Pvt Keith K. Tisch,
Pvt Eldon D. Todd,
Pvt Richard P. Trego,
Pvt Charles W. Truby,
Pvt Harry R. Turner,
Pvt Ernesto R. Valdovin,
Pvt Gene L. Vremsak,
Pvt William E. Wadden,
Pvt Donald J. Walker,
Pvt Gilbert E. Watkins,
Pvt Duane E. White,
Pvt Louis A. Whitten.
Source:
http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=7820

At 0324LT, the crew informed ATC about his position at 9,000 feet vertical to Newhall and six minutes later, he obtained the permission to descend. At 0341LT, the aircraft hit the slope of Mt White located 14 miles south of Lebec and disintegrated on impact. All 11 occupants were killed. It appears that at the time of the accident, the aircraft was off track to the east by ten miles due to strong west winds, and it hit the mountain 75 feet below the summit.

The aircraft was heard southwest of the airport at 0327 and at this time Cleveland Tower cleared the flight to land on Runway 36-Left. At 0328 the air-craft was observed over the airport at an altitude of between 200 and 400 feet flying In a northeasterly direction. When approximately over the north boundary, the aircraft disappeared from view in what appeared to be a low cloud formation. At this time Cleveland Tower advised the flight that It was cleared to use Runway 36-Left, Runway 36-Right, or Runway 31, at the captain's discretion. The aircraft was next seen re-approaching the airport from the northeast in a right turn, during which turn the landing lights were switched on. In the latter part of the turn, a descent was established and this descent was continued in a northwesterly direction toward the dark, undeveloped area north of the airport. With the exception of the fact that the aircraft was heading toward an area not within the boundary of the airport, its appearance was that of an aircraft in a normal landing approach. When at an altitude of approximately 30 feet, the aircraft banked slightly to the left and, immediately thereafter it struck trees and high tension lines paralleling the north boundary of the airport. The aircraft veered sharply to the right and dived into the ground, coming to rest approximately 550 feet beyond the point of initial contact.

The aircraft left Jackson at 1630LT bound for Meridian and the crew obtained the permission to continue at an altitude of 3,000 feet in IFR mode. The approach to Meridian was started in the following weather conditions: ceiling 800 feet, overcast, visibility 3 miles, thunder storm, light rain showers, surface wind northeast 10, thunder storms overhead moving east-northeast, frequent vivid lightning all quadrants. The aircraft was seen to make contact with the runway within the first 1,000 feet, however. it continued rolling down the entire length of the runway with little apparent deceleration. Its forward motion continued beyond the end of the runway and up the western slope of a ditch adjoining the highway adjacent to the airport. on striking this ditch, the aircraft left the ground and bounced over the highway, coming to rest with its nose extended partially over a railroad right-of-way. All 22 occupants escaped unhurt while the aircraft was damaged beyond repair.

The Anchorage runway had been cleared with snow for a distance of 3200 feet and width 30 feet. The copilot was instructed to hold the throttles and keep them from retarding on takeoff. As the aircraft ran into snow with the left wheel the pilot removed his hands from the throttles to use trim tabs. As the aircraft became airborne the throttles retarded because the co-pilot neglected to hold them. Full power was added, but it was too late since the aircraft stalled and crashed back into the runway.
Source:
http://aviation-safety.net/database/record.php?id=19461109-0

Enroute, the crew was informed that weather conditions in Cheyenne were poor and was rerouted to Laramie. Unfortunately, upon arrival, weather conditions were not so good with light snow and a visibility of two miles. The captain decided to attempt to land but was unable to locate the airport and passed over without seeing it. Shortly later, while at an altitude of 75 feet and in a left bank of 70°, the aircraft hit the ground with its left wing, crashed and burned. All 13 occupants were killed.

The crew was performing a positioning flight to Wilmington-New Castle Airport to pick up passengers. On approach, the crew was informed by ATC that weather conditions were poor and that it should be better to divert to Philadelphia. The pilot attempted to land on runway 14 but after touchdown, he realized his mistake and elected to go around. It was too late, the aircraft overran, went through the perimeter fence, crossed a road where it hit two cars and continued for about 650 feet before coming to rest in flames. While all eight crew members escaped unhurt, the aircraft was destroyed.

The four engine aircraft left Atlanta Airport at 2027LT bound for Newark with an intermediate stop in Washington-National Airport. While flying on airway Green 6 at an altitude of 7,000 feet, the crew was informed by ATC that a landing in Washington was not possible due to poor weather conditions and that he should proceed direct to Newark. Two hours later, the crew received new instructions from ATC: as weather conditions improved in Washington, a landing was therefore possible. The crew modified his route and started the descent to the National Airport. Due to low visibility, the first attempt to land was abandoned and the crew completed a go around. On the second approach, while at a height of 200 feet, the aircraft hit the slope of a small hill, bounced, snatched two telephone poles and crashed in flames near Alexandria, about 6 miles southwest of the airport. Quickly on the scene, the rescue teams were able to evacuate all 26 occupants, some of them injured, while the aircraft was destroyed by a post crash fire.

Crashed in foggy conditions near Springfield, killing all five crew members.

An approach from the west was then decided on by the Captain as visibility there had been fair. The First Officer contacted the tower and was cleared to land on Runway 12 (to the southeast). While headed west the Captain started a gradual left turn at the western boundary of the field, continued it for a short time and then entered a right turn in an attempt to line up with and land on Runway 12. This right turn was continued at an altitude of some 200 feet above the ground with, wheels down, 15 degree of flap and airspeed of approximately 120 mph (once as low as 110 mph). The Captain instructed the First Officer, who occupied the right hand pilot seat, (on the low and field side of the turn) to "sing out" when he saw the field. When the First Officer did see it he said "There's the field at 2 o'clock" (at a relative bearing of 60 degree). The Captain then leaned to the right to see the field himself and during this momentary diversion from the instruments enough altitude was lost to permit the right wing tip to strike the ground. The site was on rolling prairie approximately 20 feet higher than, and about 1 1/2 miles northwest of the Cheyenne Airport, on the U. S. Military Reservation of Fort Warren. At the instant of impact the aircraft was still in a right turn, banked approximately 15 degree and headed northeast. It came to rest about 700 feet beyond the point of first impact. A gasoline fire developed on the ground along the crash path and the right wing, which had been torn from the fuselage, was partly burned. Two passengers were killed while most of the other occupants were injured, some of them seriously.