United States of America

This Catalina had been modified to accommodate a nine lens aerial mapping camera developed by the Coast & Geodetic Survey. The aircraft was manned by a combined crew of Coast Guard and Coast & Geodetic Survey personnel when it crashed into Mount Moffett located 5 miles northwest of Adak, Aleutians Islands, while on a survey mission. All eight crew members were killed.
Crew:
L/Cdr George O. Olson,
Cdr Harry A. Bolles,
L/Cdr Edward L. Carpenter Jr.,
Ens Joe A. Sosbee,
Ens Ray B. Elliott,
Amm Charles E. Isakson,
Rm2 Arthur A. Boeke,
Amm Curtis K. Drennan.
Source: http://www.check-six.com/

The aircraft left Grenada AFB for a combined exercise with five other Dakotas. En route, while cruising at at altitude of 1,200 feet, the aircraft collided with a USAF C-47-DL registered 41-38730 and carrying a crew of six. Both aircraft went out of control, dove into the ground and crashed in a field located 10 miles north of the airbase. All ten crew members on both aircraft were killed.
Crew:
2nd Lt David P. Brubaker,
2nd Lt Edward A. Heflin Jr.,
S/Sgt Leslie L. Lamb,
Cpl Henry C. Manson.

The aircraft left Grenada AFB for a combined exercise with five other Dakotas. En route, while cruising at at altitude of 1,200 feet, the aircraft collided with a USAF C-53D-DO Skytrooper registered 42-6464 and carrying a crew of four. Both aircraft went out of control, dove into the ground and crashed in a field located 10 miles north of the airbase. All ten crew members on both aircraft were killed.
Crew:
F/O Thomas W. Carroll,
2nd Lt Harland G. Clendenin,
S/Sgt Olen W. Goodner,
Cpl John F. Marshal,
Cpl Paul D. Mullins,
Cpl Millard G. Unger.

The crew was engaged in a training flight with a group of six Dakota that left a local air base in the afternoon to complete a combined exercise. En route, while in a V formation, a C-47 registered 42-23786 and carrying a crew of four went off course and hit with its right wing the left wing of the C-53. Following the collision, both aircraft went out of control, dove into the ground and crashed in a field located 19 miles west of Hemingford. All eight crew members in both aircraft were killed.

The crew was engaged in a training flight with a group of six Dakota that left a local air base in the afternoon to complete a combined exercise. En route, while in a V formation, the C-47 went off course and hit with its right wing the left wing of a USAF C-53 registered 42-68785 and carrying a crew of four. Following the collision, both aircraft went out of control, dove into the ground and crashed in a field located 19 miles west of Hemingford. All eight crew members in both aircraft were killed.

On final approach, at a height of 50 feet, the aircraft bank left, stalled and crashed in flames short of runway 31 threshold. Three passengers and three crew members were killed.

The C-40A was flying in formation with a C-54 registered 41-37271, so his crew could photograph the dropping of a dummy combat tank from the C-54. After the tank was released, the pilot of the C-40A made a quick turn to the left, striking the C-54 right wingtip. The C-40A entered a spin and crashed near the runway, killing all five crew members. The C-54 continued on for 700 feet, allowing two passengers to bail out. The plane then crashed in a vertical dive, killing three other crewmen.
Source: http://www.joebaugher.com/

The C-54 was flying in formation with a Lockheed C-40A Electra Junior registered 38-546, so his crew could photograph the dropping of a dummy combat tank from the C-54. After the tank was released, the pilot of the C-40A made a quick turn to the left, striking the C-54 right wingtip. The C-40A entered a spin and crashed near the runway, killing all five crew members. The C-54 continued on for 700 feet, allowing two passengers to bail out. The plane then crashed in a vertical dive, killing three other crewmen.
Source: http://www.joebaugher.com/

Crashed in unknown circumstances into the Mobile Bay, off Mobile, killing all five crew members.

Six minutes after take off from Dutch Harbor Airport, while climbing, the aircraft crashed on Mt Table Top. All ten crew members were killed.