United States Air Force - USAF (since 1947)

As the aircraft was about to take off for its return flight to Phan Rang, the pilot saw a huge thunderstorm directly in its path and decided to abort the flight. He was observed to taxi along the runway to return to the parking area and had covered about 2,000 feet when the tower warned him to clear the runway immediately. However, before the Provider could turn off the runway it was hit by a Thunderchief as it landed in poor visibility. The F-105's starboard wing sliced through the left side of the C-123's fuselage and the jet's fuselage tore off both the Provider's engines from its port wing. The Thunderchief pilot died in the collision and the burning aircraft tumbled down the runway for another 5,000 feet. All the C-123 crew escaped with burns, although one of them died from his injuries few days later.
Source: Chris Hobson

During a resupply mission to the Marine Corps based at Khe Sanh, at Hercules crashed short of the runway during a GCA approach and caught fire, killing all but one of the crew. The aircraft was attempting to deliver a load of sandbags by flying low and slow over the runway and pushing them out of the back. The sandbags were needed as part of a major reconstruction programme at the base and had to airdropped as the runway was being rebuilt. The weather was poor at the time with a low cloud base and the accident was thought to have been due to pilot error rather than enemy action.
Crew:
Cpt Erie Lawrence Bjorke,
1st Lt James Randall Hottenroth,
T/Sgt Edward Mosley,
A2C John Herbert Snyder,
Sgt Charles Lynn Baney.
Source: Chris Hobson

While taking off from Đắk Tô Airport, the airplane collided with a bulldozer. The driver was killed and the crew was able to continue the takeoff procedure and to land at Cam Ranh Bay Airport without further problems. However, the aircraft was later considered as damaged beyond repair.

Ten minutes after takeoff from Huế Airport, while climbing in marginal weather conditions, the crew failed to realize his altitude was insufficient when the airplane struck the slope of a mountain (1,850 feet high) located about 10 km from the airfield. The wreckage was found two days later about 150 feet below the summit and all 24 occupants have been killed. It appears the aircraft struck the mountain at a speed of 465 km/h. At the time of the accident, the mountain was shrouded in clouds.
Crew:
Lt Col Christopher Braybrooke,
Maj Robert William Anderson,
Cpt Scott McClelland Burkett,
A1C Terry Michael Rehm,
A2C Ronald Paul Ruyf.

While flying at low height, the airplane was shot down by enemy fire (artillery) and crashed in flames about 64 km south of Huế. All seven crew members were killed.
Crew:
Lt Col Van Harold Newville,
Cpt Arthur Raymond Coughlin,
Maj William Whitby Duck,
M/Sgt Charles Joseph Rogiers,
T/Sgt James Charles Krouse,
A2C William Ward Scoville,
A2C Walter Clarence Wright.

The crew was completing a flight from Biên Hòa to Nha Trang with an intermediate stop at Bảo Lộc. While on approach, the pilot-in-command failed to realize his altitude was insufficient when the airplane struck the slope of a wooded mountain located some 19 km southwest of Bảo Lộc Airport. The aircraft was destroyed and all 11 occupants were killed.
Crew:
Lt Col Merle Deane Turner,
Cpt Edward Louis Goucher,
A1C james Russell Mayo.

Shortly after takeoff from Howard AFB, the airplane stalled and crashed, killing all nine crew members.

While approaching a US special Army Forces camp, the airplane was mistakenly shot down by a US 155 mm howitzer. The tail was torn off and out of control, the airplane dove into the ground and crashed. All three crew members were killed.
Crew:
Cpt Alan Eugene Hendrickson,
Cpt John Dudley Wiley,
T/Sgt Zane AUbry Carter.

While flying at a height of 150 feet on a supply mission, the airplane was hit by enemy artillery and crashed in flames in a dense wooded area. All five crew members were killed.
Crew:
Lt Col Everett Edward Foster,
Maj Allan Julius Stearns,
Maj Donald Thomas Steinbrunner,
S/Sgt Irvin Grant Weyandt,
Sgt Le Tan Bo.

After liftoff at Offutt AFB, the airplane encountered difficulties to gain height, stalled and crashed in flames about a mile past the runway end. A crew member was killed while four others were injured. The aircraft was destroyed.