de Havilland DHC-2 Beaver (2024)

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Summary

You first notice the sound as a low rumble in the distance. It grows louder, and the throaty rumble increases to a roar as the big floatplane swings into the wind for landing. On this remote northern lake where you've been stranded by weather for days, this is the sound of salvation. A hard working Pratt and Whitney radial engine, firmly attached to arguably the best bush airplane ever built is on its way to pick you up and deliver you to the land of hot showers and warm beds. And as I was once told by a well known pilot in Kodiak when I began flying a Beaver, "You won't find a better airplane for flying in marginal weather in the bush."

That airplane—the de Havilland Beaver, celebrates a birthday this August—seventy-five years from its first flight. Officially known as the de Havilland Canada DHC-2 Mk.I Beaver, it is listed as one of the ten greatest inventions ever created in Canada. More significantly, there's probably not a backcountry pilot around who's flown one that doesn't have a soft spot in his or her heart for this reliable workhorse.

What makes the Beaver such a wonderful working airplane? A great team of designers paid careful attention to the original design objective, as well as to the responses of a survey of working pilots in the north and produced what has become an icon of bush aviation. The team of Phil Garratt, Jaki Jakimiuk, Fred Buller and Dick Hisco*cks created not just a bush airplane, but a legend.

The goal of these designers was to develop a purpose built bush airplane, capable of carrying heavy loads on wheels, skis and floats, and with performance to meet the demands of the bush operators of the day. The final design of the airplane was dictated by the decision to utilize the Pratt and Whitney R-985 Wasp Junior radial engine as its powerplant instead of a 330 hp British built Gypsy engine, which was the first choice of the designers. The R-985 was first built in 1929, and today there are still hundreds of these engines in service in many different airframes. Were it not for the durability of the Beaver, the R-985 would probably now be uncommon in the ranks of working engines, but the two have proven to be a match made in Downsview.—Ontario, that is-home of DHC, and birthplace of the Beaver.

It was the switch from the inline Gypsy engine to the P & W radial which gave the Beaver its pug nose. To provide loading flexibility, the big engine had to be mounted virtually in the co*ckpit. In fact, the six gallon (yes, you read that correctly) engine oil tank IS the center console between the pilot and copilot's feet in the Beaver.

The oil filler cap and dipstick is located on the right side of the center pedestal, adjacent the copilot's left knee. Theoretically one can add oil in flight, though I never felt compelled to attempt it. I always briefed my passengers not to remove the big yellow cap after an incident during a flight in Kodiak. While flying a group of VIP's on a tour of the island, the Regional Director of my agency was in the right front seat. For reasons known only to him, he reached over and opened the oil filler cap in flight. A rather large glop of nasty looking and very black 50 weight oil burped out of the filler onto his left pant leg, at which point he calmly replaced the filler cap and returned to surveying the countryside as if nothing had happened. Maybe that engine was carrying a bit of pressure in the tank but I saw no point in opening the cap in flight again.

The Beaver was designed from the outset to operate in all seasons, and much of the original flight testing was done on floats. Many Beavers operating today are float-equipped, a testament to the superb performance of the airplane on floats.

The first production Beaver was delivered in early 1948. By the end of production, 1,631 Mk.I Beavers had been built, a single Mk.II prototype was built with an Alvis Leonides 500 hp engine, but never produced, and 60 Mk.III Turbo Beavers were built. The US military bought 968 Mk.I Beavers as U-20 utility aircraft. For years, Kenmore Air Harbor in Seattle has done a lively business converting military Beavers to civilian configuration.

The prototype Beaver illustrates the durability of the type. The first Beaver, CF-FHB, first flew in August of 1947. After flight testing was complete it was refurbished as a factory demonstrator. Flown to British Columbia as a demonstrator, the airplane was sold to Central British Columbia Airways in June of 1948 since CBCA was in need of working aircraft. FHB then became a hard working air taxi airplane. The prototype continued to fly for several northern air taxi operators until 1980, when the National Aviation Museum in Ottawa tracked it down, purchased it and retired it to display status. How many aircraft manufacturers can claim that a flight test prototype of one of their aircraft was in continuous, day to day commercial service for 32 years?

So, what's it like to fly a Beaver? It can be a lot of fun, and a lot of work. This is a big airplane by general aviation standards, with a gross weight of 5,100 pounds and the engine puts out 450 horsepower at full lope. The engine is supercharged, and the airplane can have up to six fuel tanks. Modifications to the airplane have now made a gross weight of 5,600 pounds possible for modified Mk.I Beavers, and 6,000 pounds for Mk.III Beavers. These are not terribly complex airplanes, but they're not that simple either.

Loading a Beaver can be a daunting task—the useful load can be close to 2000 pounds even on floats. The shape of the doors on a Beaver appears odd initially. The front doors are narrow, but after flying one, you realize that it's a functional shape. The aft doors were designed to facilitate the loading of 55 gallon barrels, either upright or on their sides, and the shape of the doors fits this purpose perfectly. Each spring in Kodiak, I moved fuel from a vessel anchored in an ocean bay to one of our lake camps. Over the course of a few days, I'd move 70 barrels of avgas and Jet A, and twenty 100 pound cylinders of propane from that boat into N765—three barrels at a time— then unload at the lake using a ramp. These are working airplanes, and designed for hard use.

Three fuel tanks occupy the forward belly of the airplane, which simplifies fueling. There's no need for the pilot to climb up on the wings to fuel. Many Beavers have wing tip tanks, but with 95 gallons in the belly tanks (35, 35 and 25 gallons), the tips (another 46 gallons) are rarely used. Fuel management requires planning to maintain center of gravity as fuel is burned.

The first procedure new Beaver pilots learn is engine starting. Radial engines require a few more steps in the process than do opposed engines. Hydraulic lock is a possibility in a radial that hasn't been run for a bit. Oil can leak past the piston rings and pool in the lower combustion chambers, and starting an engine in this case will create havoc, but shorten the pilot's work day...and career.

The morning ritual for a Beaver pilot starts by pulling that big propeller through by hand several blades to verify there's no hydraulic lock. Then give it five strokes of prime, engage the starter, count three to five blades, energize the boost coil and switch on the mags. Five cylinders are primed, so they fire first, then the others join in, which gives the radial's start its characteristic harmony. This process is often accompanied by a cloud of smoke as the engine clears its throat in preparation for the day's work. The sound of a radial engine coming to life has been known to bring tears to the eyes of hard core biker types. It is a sweet sound indeed.

Longevity of radial engines is dependent on a thorough warm up prior to takeoff—every day. In the cool climate of Kodiak, a ten to fifteen minute ground warmup was standard, even in summer. With the airplane tied down, I'd fire up the engine, pour a cup of coffee from my thermos and read the morning paper while the Junior warmed itself for the day's adventures. There's six gallons of oil in there, and a lot of metal to warm.

The Beaver is slab sided, and sensitive to wind on the surface, but an experienced pilot can handle the airplane easily enough. For takeoff water rudders are retracted, and the throttle brings manifold pressure to 36.5 inches at 2300 rpm for takeoff. An idling 985 rumbles a pleasant note, but at takeoff power it emits a deafening roar. Attention to manifold pressure is essential since it's easy to over-boost the engine. Our Maintenance Chief told me that if I saw trees in the top half of the windshield during a takeoff, I should shove the throttle all the way to the stop. If I missed the trees, call him and we'd talk about the next step. On at least one such occasion, I cleared the trees with the MP gauge reading well over 40 inches, and thankful for a strong engine.

On takeoff the Beaver struts its stuff. This is what the airplane was bred for—STOL operations. Even heavy, the airplane outperforms most four to six seat airplanes. With modifications, the Mk.I Beaver can seat seven, the Mk.III Turbo Beaver can seat as many as ten. Ask any experienced pilot who's flown the Beaver and other bush airplanes which he or she would choose to depart a small lake with a load, and the answer will be predictable.

Takeoff requires flaps. The designers refused to follow popular recommendations, and drooped the ailerons when flaps deploy. These "flaperons" significantly improve the STOL capability of the airplane. For takeoff, I lowered flaps to match aileron deflection with the yoke cranked over fully in one direction. Once airborne, the Beaver's control harmony is actually quite nice and light. Adverse yaw is prominent so proper use of the rudder is required. With a 48 foot wingspan, a "leisurely" roll rate and lots of adverse yaw is inevitable.

The Mk.I Beaver-heavily loaded does not exhibit spectacular climb rate, but with patience and bumps of the throttle to maintain power during the climb it'll get you there. The airplane climbs best with partial flaps. Engine temperatures may limit climb performance on hot days. Cruise speed of a loaded float equipped Beaver is around 110 mph. When I first flew the airplane, it seemed difficult to find a proper cruise pitch attitude, because of the rounded cowling. I learned to level the bottom of the left wing with the horizon, and I flew with a bit of flaps deployed when heavy. Flaps are hydraulically actuated, permitting an infinite range of deflection. Fuel burn in cruise ranges from 22 to 28 gallons per hour.

On approach, the Beaver exhibits a characteristic typical of de Havilland Canada aircraft: a very nose low pitch attitude is required to maintain airspeed. These airplanes illustrate the concept of flight "behind the power curve" graphically. These are draggy airplanes, and raising the nose increases drag exponentially. As a Beaver slows, you must keep the nose down. Get low on final, raise the nose and the airplane will sink like a stone. The airplane won't climb, even with max power until the pilot pushes the nose DOWN. Push and the airplane will climb nicely, assuming it's not too far into this corner before the pilot takes corrective action. My mentor Jack Corey flew an Otter into the ground with a big load in just this configuration, so my initial checkout in the Beaver included an extensive exposure to this behavior. Everyone's checkout in these airplanes should as well.

Landings in a Beaver are non-events. The airplane flares and settles on quite nicely: all in all a gentle lady. Got some rough water to work? That's the Beaver's job. It's big, tough and as honest an airplane as was ever built, assuming the pilot approaches properly. The airplane has the capability of extreme flap deployment—58 degrees, with a note in the pilot's handbook recommending that "the full flap setting should be used only for emergency crash landings". Interesting concept.

The Beaver has been "improved" by numerous modifiers. de Havilland itself adapted the Mk.1 to turbine power to create the Mk.III Turbo Beaver, with a Pratt and Whitney PT6 engine. Sixty were built at the Downsview, Ontario factory in the late sixties. The difference in weights required a 28 inch extension to the fuselage aft of the pilot's seat to keep the Mk.III in CG. A larger rudder and vertical fin manage the additional horsepower from the turbine engine.

Modifications exist for a gross weight of 5,600 pounds for Mk.I Beavers, and 6,000 pounds for Mk.III Beavers. Numerous seating arrangements, larger cargo doors , larger windows, and smaller batteries have all been approved. The induction has been moved to the top cowl to reduce water ingestion, the wing struts have been strengthened—the list is extensive. Viking Air, Ltd in British Columbia now owns the Beaver type certificate. For a price, they will convert a Mk.I Beaver to a Mk.III configuration-turning your rumbler into a whiner, so to speak. Wipaire in Minnesota has developed its own turbine conversion for the Beaver, a quite different machine than the Mk.III Beaver, but with many attractive features of its own, including greater fuel capacity and a fuel system similar to the Cessna Caravan.

Whether modified or stock, the Beaver is and has been for sixty years the recognized workhorse of the north country. A harder working, more productive bush airplane has not been built, and Beavers are today being refurbished and put back to work at a price that I'm sure the designers couldn't have imagined in 1947.

When test pilot Russ Bannock made that first flight in Beaver CF-FHB on August 16, 1947 he knew DHC had a winner, but I doubt that he ever dreamed of the impact on bush aviation and the tenacity that the Beaver would display.

Model distinctions

Specifications

Notable issues

Suggest other valuable backcountry-oriented options of mods for this aircraft.