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De Havilland Canada Twin Otter – 50 Years Not Out By Howard Wheeldon, FRAeS, Wheeldon Strategic Advisory Ltd.

twinotterHaving first entered service with the Ontario Department of Lakes and Forrest in August 1966, while the de Havilland Canada DHC-6 Twin Otter may be unable to claim to have had over 50 years of unbroken production, due to a 21 year gap in production that occurred between 1986 and 2007, it is undoubtedly an aeroplane that has proved itself to be one of the most durable and flexible utility aircraft still in production today.

With military and business related news-flow somewhat on the quiet side and with many people now taking a well-earned vacation it is nice to write about something completely different. That is what I intend to do today continuing an occasional series talking about past aircraft capability, both military and commercials, that we often just take for granted. Regular readers will remember that a couple of weeks ago I devoted a section of one of my commentary pieces to a celebration of the seventieth anniversary of the first flight of the de Havilland Canada DHC-1 Chipmunk. As I had anticipated when I circulated the piece, a number of former Royal Air Force pilots that had begun their training on this fine aircraft responded – I am pleased to say that all of them had wonderful accounts and stories to impart about this fabulous training aircraft.

In writing about yet another de Havilland aircraft success today, in this case the DHC-6 Twin Otter, I do so in relation to an aircraft that not only celebrates the fiftieth year of its first flight in this very month, an aircraft that has been very successful in the hands of operators all over the world but also one that is, in its present 400 Series form, still being built by Viking Air in Canada.

The sturdy de Havilland Twin Otter is an aircraft that continues to win plaudits wherever it operates. Well equipped, rugged, reliable, as modern and up to date as the hour in terms of cockpit equipment and I told, an aircraft that delightful to fly the Twin Otter is undoubtedly as efficient or maybe more so than any other twin turbo-prop engine aircraft in production today. Perhaps what sets this rather taken for granted aircraft apart from its peers is, particularly with its variable landing gear options, one of the very few aircraft available today that can be said is able to work and operate just about anywhere and everywhere.

Developed from a large de Havilland Canada menagerie of aircraft that included the DHC-1 Chipmunk, DHC-2, DHC-3 Otter, DHC-4 Caribou and DHC-5 Buffalo the DHC-6 Twin Otter soon became very popular for its excellent short take-off and landing capability. Powered by two Pratt & Whitney Canada PT6A-20 turboprop engines, each developing about 578hp, depending on payload, the Twin Otter has a maximum speed of around 210 mph. It is designed to carry around 19 passengers. Unpressurised, the Twin Otter can easily be turned into amphibious capability when fitted with ski’s or floats and it is in this form that it is still regularly to be seen in the Arctic and Antarctic areas together with many other warm and cold climate areas all over the world.

I have myself flown in quite in quite a few Twin Otter aircraft particularly in and around Indonesia and Borneo back in the early eighties and I recall during that period that I also had the pleasure of flying on a private flight in the right hand seat back from Jersey to what was then a rather small and underutilised Stansted Airport as well.

While the Twin-Otter has not been without incidents it has, given the harsh environments the aircraft was designed to fly in, had a relatively good safety record over the fifty years that is has been in production so far.

By the time the first 22 year production run of the Twin Otter Series 100 to 300 ended in 1988 844 aircraft had been built. According to Viking Air, the company responsible for not only providing maintenance and spares support to all Twin Otter users but who were responsible for restarting of production in 2010, around 500 legacy aircraft remain in current operation. In addition, around 75 Series 400 aircraft have been delivered since the first in 2010.

As alluded above, the ending in 1986 of the original de Havilland Canada Twin Otter production line occurred around the time that Boeing had acquired de Havilland Canada was not to be the end of Twin Otter production although it did mark a gap of at least 21 years before the idea of restarting production was agreed. It is probably correct to say that Boeing struggled with its Canadian subsidiary during its six years of ownership so it was hardly surprising that in 1992 Boeing sold the de Havilland Canada operation to Bombardier. That particular marriage brought the Dash 8-100 and Dash 8-300 series production, turboprop aircraft capable of seating up to 40 passengers and that would see Bombardier through a very successful period for many years to come.

It should be reminded here that before de Havilland Canada had been sold to Boeing in 1986, (it was known then as de Havilland Aircraft of Canada) the company had been part of Hawker Siddeley Aircraft, a UK company founded in 1935 through the purchase by Hawker Aircraft of companies such as J D Siddeley, Armstrong Whitworth Aircraft and some little time later, A V Roe (this company also had a Canadian operation which later merged with that of de Havilland Canada) and Gloster Aircraft. Having acquired Folland Aircraft in 1959, the parent Hawker Siddeley Company acquired de Havilland Canada through its acquisition of the parent company, the de Havilland Aircraft Co which at that time was best known as the developer of the Comet and that was also very active developing the Trident passenger aircraft. The latter acquisition occurred in 1960, the same year that Hawker Siddeley also acquired Blackburn Aircraft.

(Two additional points of interest here:

  1. November 21st 2016 will mark the fiftieth anniversary of the announcement by the Harold Wilson Labour Government in 1966 of the proposed nationalisation of Hawker Siddeley Aviation and what was then known as the British Aircraft Corporation.
  2. June 3rd 2016 marked the fiftieth anniversary of the crash, due to an in-flight super-stall, of the de Havilland Trident 1C aircraft G-ARPY which had been the 23rd of 24 of the Trident aircraft type ordered by British European Airways. The crash occurred during a routine pre-delivery production test flight and led to the loss of life of all on board including test pilot, George B.S Errington and co-pilot Peter Barlow together with two technicians),

Back to the Twin Otter. As already mentioned, in order to maintain spares and replacement parts for the aircraft in service all remaining tooling Type Certificate of the Twin Otter were purchased by a British Columbia based company Viking Air in 2005. The purchase agreement was followed by a separate deal in 2006 in which Viking Air acquired type certificates for all out of production de Havilland Canada aircraft including the DHC-1 right through to the DHC-7. Later that year Viking announced an intention to restart Twin Otter production in a new final assembly plant in Calgary, Alberta with the series 400 powered by uprated Pratt & Whitney Canada PT6A-34 engines.

Production of the Twin Otter 400 series by Viking Air continues and combined orders and production of the aircraft since production restarted in 2010 the company has received orders for in excess of 120 aircraft. A year ago Viking Air announced that a distribution partnership had been established with a Chinese company called Reignwood Aviation that included purchase of 50 new Twin Otter 400 series aircraft.

Long may the success of the Twin Otter aircraft continue.

(I am away on a military related visit for the next two days – Commentary will return on Thursday)

CHW (London – 16th August 2016)

Howard Wheeldon FRAeS

hwheeldon@wheeldonstrategic.com

Tel: 07710 779785

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