Phú Yên Province

The aircraft was returning from Tuy Hòa from a Special Forces mission to Biên Hòa and had already radioed Tuy Hòa tower that it was 15 miles south for a landing. This radio call was the last thing heard from the aircraft. Witnesses testified that the aircraft was seen burning in flight and impacted into the South China Sea in two parts about eight miles south of Tuy Hoa. Neither the aircraft nor the remains of three crew members have been recovered.

After landing on runway 03 at Tuy Hòa Airport, the airplane was unable to stop within the remaining distance, overran and came to rest into the sea. There were no casualties.

Crashed in unknown circumstances 19 km southwest of Ty Hóa. The crew fate remains unknown.

The four engine aircraft was on its way from Cam Ranh Bay to Kadena AFB, Okinawa, carrying a crew of eight. While cruising along the Vietnam shore, about 72 km northeast of Nha Trang, the airplane suffered an in-flight explosion and crashed into the sea off Phú Hiệp. All eight crew members were killed.
Crew:
Lt Cdr Ralph Burton Cobbs,
Lt Donald Edwin Siegwarth,
Lt Clement Olin Stevenson,
Lt Edward Leon Romig,
AN M. J. Savoy,
YN2 Jack Ishum Dempsey,
ADJ2 Curtis David Collette,
ADR2 Stanley Jon Freng.

Due to a failure in the propeller pitch mechanism one of the engines' propellers could not be used to decelerate. The airplane swerved off the runway into a ditch, in an attempt to avoid a truck at the end of the runway. Damage was repairable, but the Hercules was damaged beyond repair when recovery crew attempted to tow the airplane using a tank and a steel cable through openings in the fuselage.
Source: Chris Hobson

The aircraft was attempting to land at Tuy Hòa Airport under a very low cloud base when it was hit by ground fire 8 km south of the airbase and crashed killing all five crew members. The airplane, based at Nha Trang, was bringing in a load of 13 tons of aviation fuel and it was 1st Lt Smith's first mission as aircraft commander. Enemy action was never actually confirmed to have caused the loss of this aircraft which may simply have flown into high ground in poor visibility. For some reason the remains of 1st Lt Wax were not recovered and identified until December 1996.
Crew:
1st Lt Donald Clayton Smith,
1st David J. Wax,
Cpt Terry Fisher Katterhenry,
T/Sgt William Henry Crisp,
A1C Willie Mitchell.
Source: Chris Hobson

While descending to Tuy Hòa Airport, the crew encountered poor weather conditions with rain falls. While flying at low height, the airplane struck tree tops then stalled and crashed in a dense wooded area located about 30 km east of the Tuy Hòa Airfield. As the airplane crashed in an enemy zone, it was not possible to intervene immediately and the first rescuers reached the crash site two weeks later only. The aircraft was totally destroyed and all 85 occupants were killed. At the time of the accident, the ceiling was down to 50 feet from the ground and the crew was apparently not aware of his too low altitude.
Crew:
Maj Robert Milvoy Horsky,
Cpt George Parker McKnight,
S/Sgt Mercedes Perez Salinas,
S/Sgt Donald David Stewart.