Otter 299 was delivered to the United States Army on 14th November 1958 with serial 58-1690 (tail number 81690). It was assigned to the 17th Aviation Company, Fort Ord, California. It was delivered from Downsview to the Sharpe Army Depot, Stockton, California, before continuing on to Fort Ord. It was re-assigned to the 18th Aviation Company for deployment to Vietnam in January 1962. It continued to fly for the 18th Aviation Company in Vietnam until destroyed in December 1963.
At 07:22 hours on 12th December 1963, 81690 took off from Ban Me Thuot on a scheduled courier run. The crew filed a flight plan with Pyramid Control after take off and completed the first leg of their run to Nha Trang. Before take off from Nha Trang, the front and centre tanks were filled with fuel, as was the oil tank, taking three gallons after three hours of flight. In addition to the crew of three (two pilots and a crew chief), there were four passengers and three hundred pounds of baggage, making the gross weight at take off approximately 7,700 pounds. The pilot evidently elected to make the return flight to Ban Me Thuot on top of the weather, because of turbulence caused by strong winds. The route usually flown was through one of two passes to the northwest of Nha Trang. Both passes were reported open that morning, with about 1,500 feet of terrain clearance.
When the Otter became overdue on its flight plan arrival time, the Air Force notified the 18th Aviation Company. Calls were made to all possible landing fields in an attempt to locate the aircraft, with negative results. It was too late to start search operations that night, so plans were made to start at sunrise the next day. Cessna TO-1D Bird Dogs, UH-1B Huey helicopters and other 18th Aviation Company Otters participated in the search. At 10:00 hours on the morning of the 13th December, one of the Bird Dogs climbing out of moderate turbulence encountered at the base of Mountain 7890, spotted a piece of metal in the trees on the side of the mountain, at the 7,400 foot level. It transpired to be the wing of the Otter. That afternoon, the advance party of the rescue and recovery team was airlifted to the top of the mountain in a UH-1B. While hovering, some of the men jumped into the brush and began clearing a landing area. The remainder of the team soon landed and the party started down the 70 degree slope towards the crash site. Sadly, all seven souls on board the Otter had perished in the crash.
The hole in the trees through which the aircraft had passed indicated that the U-1A was close to a level flight attitude when it hit the trees. The right wing was sheared off while the left wing was folded back. Fire had destroyed much of the fuselage. The cause of the crash was never determined. It appears that 81690 simply flew into the side of the mountain. The cloud tops that day were reported to be 8,000 feet, which would have obscured the top of the mountain. However, the pilot was thoroughly familiar with the terrain between Nha Trang and Ban Me Thuot and was not in the habit of flying through clouds on a VFR flight plan. It was possible that the Otter had taken a belly hit from a high calibre weapon, the impact of which killed or knocked unconscious the crew and it then flew into the mountain. Whatever the cause, Captain Clarence Moorer, 2nd Lieutenant Louis Carricarte and crew chief SP4 Martin of the 18th Aviation Company were the first Otter crewmen to lose their lives in the Vietnam War.
Full history up to 2005 courtesy of Karl E Hayes © from DHC-3 Otter - A History (CD-ROM 2005)