<p>Canada's prime bushplane first flew on 16 August 1947, and proved an instant success with operators in harsh terrain the world over. Of the 1,657 basic Beaver Is built, no fewer than 980 were bought by the US Army and Air Force. The first six were designated YL-20 (four for the Air Force, two for the Army) and were off-the-shelf Canadian production aircraft. These easily won a 1951 competition for a new liaison type but, before large-scale deliveries could begin, a Congressional hearing had to be won to allow the purchase of a foreign type.
</p>
<p>With this formality behind, the L-20A/B began entering service with both users in large numbers. The US aircraft differed only in terms of equipment and instrumentation from the Canadian civil model. The majority served with the Army, and were soon in action in Korea. Over 200 were used by the Air Force on a wide variety of utility transport missions. Many were used to support outlying missile silo sites in the Midwest after the ICBM force was put in place. In 1962, the type was redesignated the U-6A.
</p>
<p>Many years after having been replaced on transport tasks by helicopters, the last U-6A on Air Force charge was retired in 1994, having served with the Test Pilot School at Edwards AFB.
