Otter 118 was delivered to the United States Army on 19th May 1956 with serial 55-3272 (tail number 53272). It was allocated to the 14th Army Aviation Company, Fort Riley, Kansas. In August 1956 the 14th was re-designated the 1st Aviation Company and moved to Fort Benning, Georgia but 53272 remained based at Fort Riley, where it was noted in January 1957. Later that year it was selected to take part in an airborne radar experiment.
The University of Illinois had entered a tri-services contract to develop a classified airborne radar system. The military assigned the project to the Army, who directed that an Otter be used, as it was the only Army aircraft large enough for the purpose. 53272 was the aircraft selected and it was flown back to Downsview where DHC were to perform the modifications. As the project was classified, the University of Illinois could not send the actual radar components to Canada but they did provide DHC with the dimensions and weight of the individual boxes. Using this information, DHC designed racks for all the equipment and determined the weight and balance. They also hung a large radome under each wing. The antennae were synchronized so that the starboard antenna would sweep from 0 around to 180 degrees, then the port antenna would take over and sweep from 180 back to 360 degrees. This obviously added weight and complexity, but was the only practical solution, given the Otter as the test vehicle.
This work was undertaken at Downsview, where 53272 became known as the “Radar Otter”. The flight testing was entrusted to the Army's 416th Signal Aviation Company which was based at Libby AAF, Fort Huachuca, Arizona. This unit did not have any Otters, nor any pilots qualified on the Otter. One of their number, Clyde Young, was selected and sent to Stockton, California where the 521st Engineer Company were based, which flew Otters on topographic survey duties. At that time, they had an Otter stationed at an abandoned WWII Air Corps training field at Thermal, California where a survey was being conducted. The Otter was used to ferry personnel and supplies between Stockton and Thermal. Officer Young deployed to Thermal and was checked out on the Otter. He then went to Downsview, picked up 53272 and flew it to the University of Illinois' Willard Airport near the town of Savoy, Illinois where the Radar Otter was to be based for the duration of the testing.
The flight characteristics were quite different from the standard U-1A due to an extreme aft Centre of Gravity, a different maximum gross weight and turbulence from the two radomes. There was a gasoline fuelled turbine/generator located in the rear of the cabin, with the result that the rear fuel tank could only be half filled to keep the C. of G. and the AUW within limits. Besides the pilot, a civilian technician flew in the co-pilot's seat and there was a seat in the cabin for an engineer/operator. The rest of the cabin was filled with racks of electronic equipment. On arrival at Willard Airport, the actual, classified equipment was installed and the project was up and running.
Doubts were expressed about the airworthiness of the Otter in its modified state, and it was flown to Wright Patterson AFB, Dayton, Ohio for an evaluation by the USAF, which included a T-28 chase aircraft. As Officer Young recalls “It was fun watching the T-28 pilot trying to keep his plane in the air while staying with the Otter!” After about six weeks, the project got the all clear to continue, subject to periodic checks on the ailerons. There was a concern about metal fatigue from buffeting from the radomes. 53272 returned to Willard Airport and the project continued for the next eighteen months. On conclusion of the testing, the radomes and all other equipment were removed, and 53272 reverted to standard U-1A configuration.
The Otter returned to Fort Riley, Kansas and continued to serve there until March 1962 when it was transported to Vietnam and assigned to the Headquarters Company of the 45th Transportation Battalion, based at Tan Son Nhut Air Base, Saigon. The HQ Company was assigned a few aircraft, including the Otter, for the use of the Battalion Commander and his staff. In May 1963 the Otter was re-assigned to the 52nd Aviation Battalion and in August 1963 it joined the 18th Aviation Company, where it was to serve for some years. There is one reference to the aircraft in the unit's history: “An exciting 4th July 1966 was experienced by Captain Sokowoski and CWO Messeder when they experienced engine failure in aircraft 53272. The failure occurred at 2,500 feet in the vicinity of Chu Lai. Immediately, restart procedures were initiated and proved successful. The aircraft ran intermittently and made a successful precautionary landing at Chu Lai Marine airfield. Carburettor failure was the cause of the trouble”.
In June 1968 the Otter was converted to RU-1A configuration and in December '68 joined the 2nd Signal Group. It continued to fly in Vietnam until August 1969 when it was handed over to the 388th Transportation Company who prepared it for return to the United States. The following month, September '69 it arrived at the Forest Park Army Depot, Atlanta, Georgia where it was put into storage alongside many other Otters which had been returned from Vietnam. It was deleted from the Army inventory in May 1972, but remained in storage at the depot until put up for disposal as military surplus.
53272 was one of six Army Otters purchased by Air Craftsmen Ltd of St. John, New Brunswick, all six being located at the Atlanta Depot. Air Craftsmen Ltd was a company which traded in Otters, buying military surplus aircraft, restoring them as civilian and selling them on. The six Otters were reserved on the Canadian register as CF-BEO / BEP / BEQ / BER / BEU and BEW. The Otters were flown from Atlanta to St. John, New Brunswick during October / November 1972, where they were re-built and civilianised. 53272 was registered to Air Craftsmen Ltd as CF-BEP. After re-build, it was sold in 1974 to Air Dale Flying Services Ltd, based at Wawa, Ontario. For the next 26 years, a remarkably long period, BEP continued to fly for this operator, serving the Ontario bush country. In 1977 it headed north to the Northwest Territories, when it was leased to Willy Laserich, flying out of Yellowknife and Cambridge Bay, but then it resumed service out of Wawa. Sadly, all good things must end sometime, and the registration C-FBEP was cancelled on 3rd April 2001 on the sale of the Otter to the United States.
The new owner of the Otter was Jeanne G. Porter of Homer, Alaska to whom the aircraft was registered as N104BM on 17th April 2001 for operation by Bald Mountain Air Service Inc, her company, which was also based at Homer. The aircraft joined the company's existing Otter N103SY (296) and both Otters were active during the summer of 2001, along with the company's Beaver N102SY. The aircraft were used primarily to fly tourists throughout the Katmai National Park to view bears. An estimated four thousand Alaskan Coastal Brown Bears inhabit this immense region, meaning that the Otters were kept very busy.
N104BM continued in service with Bald Mountain Air Service based out of Homer on floats during the summers of 2002 and 2003. At the end of the summer 2003 season, on 18th September '03, it was taken out of the water and brought to the airport to be put on wheels. It then made its last flight as a piston Otter, down to Vernon, BC., where it had arrived by 25th September '03. At Vernon, it was converted to a Texas Turbine by Kal Air, with the installation of a Garrett TPE-331 engine, making its first flight as such from Vernon on 21st December '03. It then departed for Bellingham, Washington before return to Homer, Alaska and continued operation by Bald Mountain Air Service.
Full history courtesy of Karl E. Hayes © from DHC-3 Otter: A History (2005).