A detailed
history of the development and uses of the Otter is contained in Sean
Rossiter’s recent book ‘Otter and Twin Otter’: The Universal Airplanes and
I wouldn’t pretend to gainsay such an august publication.
Using the same
overall configuration as the highly successful de Havilland Beaver (DHC-2) the
Otter actually began life described as the King Beaver; longer, with a wider
wingspan and far heavier, but capable of seating up to 11, the Otter was
conceived simply as a big Beaver, able to fulfil the same functions. The
aircraft features the same conventional stressed skin construction and has a
braced-wing with full-span slotted flaps, the outer portions acting as
ailerons.
A total of 466
aircraft were built between 1951 and 1967 and utilised in over 36 countries
with the military taking the bulk of orders. The US Army was the largest
customer, taking delivery of 200 aircraft commencing in 1955. The Royal
Canadian Air Force operated 66 Otters in both Transport and Search and Rescue
roles and the aircraft fulfilled a diverse range of duties operating on floats,
wheels and ski’s in locations as diverse as Antarctica and the
Civilian uses
have been diverse and even today the Otter, together with its smaller but older
brother the DHC-2 Beaver, remain the mainstay of many bush and more mainstream
airline operations. The west coast of
One of the key
disadvantages of the aircraft appears to have been a degree of sensitivity with
regard to overloading, especially as the Pratt and Witney R1340 piston engine was considered
by pilots to be a little underpowered for the airframe. The development of the
Turbo-Otter with PT-6A
and Orenda
powerplants revolutionised the aircraft and effectively gave it a new lease of
life in commercial service. However, the development of the PZL 1000hp
radial engine in