Viking Air Twin Otter 400



Retro Otter AMU Magazine Feb/Mar 2008


By Sam Longo AME, A&P


Everything old is new again.  It seems to have started with the new Volkswagen Beetle and grown from there.  You can buy a new Mini Cooper, new Mustang GT, even a new Triumph Bonneville motorcycle.  Retro is in, and it has finally landed in the world of aviation.


If you were going to build any “new” retro aircraft, I could not imagine a better candidate than the legendary DeHavilland Twin Otter.  The original prototype CF-DHC-X first flew on May 20th, 1965.  Since then over 800 of the rugged little STOL (short takeoff and land) aircraft have been produced. The “Two Otter” as it was originally called was evolutionary.  A six-foot plug was used to stretch the original single Otter fuselage.  A new wing, empennage and tricycle landing gear rounded out the major airframe changes.  The revolutionary part of the equation started when the company decided to hang two Pratt and Whitney PT6A turboprop engines on the wings.  With each engine rated at around 475 SHP (shaft horse power) the aircraft gained 50% more power for 35% less weight compared to the single R1340 Wasp radial.  With the added ability to climb on one engine, the ultimate bush plane was born.


My own experience with the Twin Otter started early in my aircraft maintenance career.  As an apprentice at Nordair, I was introduced to the type on my first tour north in Frobisher Bay (Iqaluit) on Baffin Island.  Working nights it took about eight hours to prepare one DC3 for the next day’s flights and approximately one hour to prepare two Twin Otters. This statement alone made them a bush mechanics dream machine. They could be left outside, over night, in minus 60 degree weather, and be flying after a short 45 minute pre-heat. The rugged fixed gear design, simple hydraulics, and bullet proof, PT6 engines made the aircraft very reliable and ideally suited for the harsh Arctic environment.


When I left Nordair in 1976, I returned to Toronto and landed a job at DeHavilland in Downsview, eventually ending up in test flight.  As an airframe mechanic I worked on all types of aircraft coming off the assembly lines. The Dash 7 was just getting started so at that time the Twin Otters and Buffalos were our bread and butter.  The Twin Otter was always my favorite aircraft to work on.  With standard cable operated flight controls and a simple 1500 PSI hydraulic system, controlling nose wheel steering, brakes and flaps, it was a nice basic “mechanics” airframe.  Of course by this time the aircraft had been up-rated to the PT6A-27 engines producing about 680 SHP, so the performance on wheels, skis or floats was simply stellar.  From the Arctic Circle to the deserts of Africa the aircraft performed admirably and earned a solid reputation as a rugged, reliable, go anywhere aircraft.


Personally for me flying in a Twin Otter has always been an enjoyable experience.  I have had the pleasure of flying in a West Coast Air Twin Otter on floats from Vancouver to Victoria Harbor. Taxiing to the docks at the foot of the Empress Hotel is always a treat.  I have droned lazily over the Grand Canyon in a Twin Otter “Vista Liner”.  Its large picture windows and super quiet 4 bladed propellers, helped to make it one of the most memorable flights of my life.  Flights like these make me proud to realize that I played a very small part in building a truly great Canadian aircraft.


I never quite understood the company’s wisdom when DeHavilland decided to end production of the Twin Otter.  At the time I remember thinking that the decision was wrong. The design was a proven commodity, worthy of ongoing support and development.  It took a few years but obviously others felt the same way.  Viking Air, sole proprietors of the type certificates for all of DeHavillands “Heritage Collection” aircraft, are taking the bold step to put the DHC-6 back into production.  The new Viking Twin Otters will have PT6A-34 or –35 engines rated at 750 SHP spinning 3 bladed Hartzell props, with optional 4 blade props if required. 


The Victoria based company has a solid track record overhauling and refurbishing Beaver and Otter aircraft and seem genuinely committed to keeping the DH Heritage Collection alive and well.  Their up-rated 400 series Twin Otters will no doubt out perform all previous models and are therefore already proven winners. Congratulations to Viking Air, for having the wisdom and foresight to resurrect this icon of Canadian aviation.  I have no doubt that the “Retro Otter” will be a great success, and as a Twin Otter fan from way back, please allow me to suggest a new marketing slogan; “For flight operations from dirt, snow or water, its hard to outclass the Viking Twin Otter.”