Hiller Aircraft's Model 1100 was one of three winning designs in the US Army Light Observation Helicopter - LOH program. Five helicopters were built as the YOH-5 to competed against the Bell YOH-4 and Hughes YOH-6 for production orders.The YOH-4 was eliminated and Bell went on to develop it into the civil Model 206 JetRanger. Hughes won the contract by under bidding Hiller. Fairchild bought Hiller in 1964 and the company developed their design as the FH-1100 for the civil Market. CF-DAL was in Canada with Geophysical Energy and Surveys 1967 - 75. It went to the USA registered N5594 until 2018.