First Impressions: How can you not love an airplane with the name Chipmunk! More than just a cute rodent name, however, the “Chippie” is a robust warbird that has trained thousands of military aviators over many decades.
Background: This year, 2024, marks the Centennial anniversary of the Royal Canadian Air Force (RCAF) and the Chipmunk is a large part of that history, having served as a primary trainer for 25 years.
Some points of clarification with regards to De Havilland Aircraft; the original company is the de Havilland Aircraft Company (UK) and was founded in England in 1920 by Sir Geoffery de Havilland, while de Havilland Aircraft of Canada (DHC) was initially a subsidiary and later a separate company with its own unique aircraft designs. The Chipmunk is the first completely Canadian design that DHC built. The Chipmunk was designed as the replacement for the de Havilland (UK) Tiger Moth, an open cockpit biplane, that was used as the primary trainer for most Allied air forces before and during WWII, other than the U.S. Later de Havilland Canada designs continued to demonstrate ruggedness and mission-capability required to operate in the vast and harsh landscape of Canada. Pilots and mechanics worldwide all have respect for aircraft named Beaver (DHC-2), Otter (DHC-3), Caribou (DHC-4), and Buffalo (DHC-5).
The DHC-1 was such a good design that, now with reversed roles, it was built under license by de Havilland (UK) as the T.10 and Mk.20/21/22/23 Chipmunk and in Portugal by Indústria Aeronáutica de Portugal as the Chipmunk Mk.20.
Design Characteristics: The Chippie is a tandem, tapered-wing, two-seat trainer with metal fuselage and fabric-covered flight controls and flaps. The forward 1/3 of the wing is metal and the trailing 2/3 is fabric. Although the Canadian DHC-1 and UK-built T.10s and Mk.20 series appear similar there are quite a few design differences, and many parts are not interchangeable. The Canadian Chipmunk is most easily identified by the bubble canopy while RAF and export versions have T-6-style “greenhouse” canopies. During WWII, de Havilland Canada built more than 1,000 DH.98 Mosquitos, nicknamed “the Wooden Wonder”, largely out of Canadian spruce and fir. The Chipmunk was the first production aircraft to follow this massive war effort at their Toronto factory.
Powerplant: The Gipsy Major 10 is a 145-horsepower, inverted four-cylinder, inline engine developed and built by the de Havilland Engine Company. The propeller is a Fairey Reed, all metal, fixed pitch propeller.
While not as well-known in the U.S., the Gipsy Major was a very prolific (14,615 manufactured) engine with some unique advantages. It was used on a wide variety of aircraft types (approx. 68), including the Tiger Moth. Most aircraft that that use the Gipsy Major are recognizable by the high-mounted propeller and narrow cowling that is afforded by in-line, inverted cylinders. With the crankshaft at the top of the engine, the forward visibility over a Gipsy Major is notably better than most other engines. The engine utilizes a dry oil sump and has a unique magneto timing mechanism that optimizes ignition based on throttle position. The throttle pushrod is not only connected to the carburetor but is linked to a cross-shaft that connects both magnetos via a slotted cam. The pilot’s throttle manipulation also controls the magneto timing so that with the throttle set at low idle, the timing is retarded and when the throttle is advanced, so is the ignition timing.
There are no fuel gauges in the cockpit but adjacent to the fuel caps on the wing are glass gauges that read out fuel quantity (Imperial gallons, not U.S. gallons) in both level and three-point attitudes. Each synthetic rubber bladder tank holds 12.5 Imp. gal per side for a total of 25 Imp. gal (30 U.S. gallons). Two engine driven fuel pumps supply fuel from either the left or right wing through a forward-aft actuating “fuel cock” lever located on the floor between the pilot’s legs.
Taxi/Takeoff: The bubble canopy slides fully aft, allowing easy entry into both the front and rear seats from either wing root. Rudder pedals are adjustable, but seat height is not, except by swapping out seat cushions. Strap in with a four-point military harness and take notice of the escape hatchet mounted behind the student’s and instructor’s elbows in both seats. There are four magneto switches with each set (left and right) wired in series. The student’s magneto switches are on the top left of the dash and the instructor’s (rear seat) are on top of the dash between the seats. All four must be on (up) for the proper engine operation. The mixture knob is immediately below the throttle lever but fully aft is rich and forward is lean. A catch on the throttle ensures that when the pilot retards the throttle for descent, the mixture is enrichened. There is a flap lever on the right with two positions (15˚and 30˚). The master switch, starter switch, and light switches are all mounted conveniently on top of the dash
Taxiing a Chipmunk is, well…different. With a castering tailwheel, no toe brakes, and a floor-mounted brake handle, you need three hands to taxi it. If you can awkwardly substitute your knees to hold the stick, cross your right hand over to the left to manipulate the throttle, and use your left hand to hunch over to manipulate the brake handle it becomes manageable. In order to make a slow speed turn, you must first apply rudder input, which will have no effect until you pull up on the brake handle. The magnitude that the pilot pulls up on the brake handle is the magnitude that will be applied to the brake on whichever side the rudder pedals are depressed. If this sounds as difficult as chewing gum, rubbing your belly, and patting your head, it’s because it is. Expect to taxi like a novice the first time but, like all things, repetition will make it easier.
An alternate method is to engage the brake handle with a pushbutton into the first gear tooth, which will drag the brake, but make it steerable without the up and down brake handle motion. Once you’re moving on a taxiway, prop wash over the rudder is usually enough to keep it tracking straight. The good news is that thanks to the inverted, in-line Gipsy, it’s fairly easy to see around the nose so not much swerving is required to see around the nose. The instructor in the back seat, however, requires a little faith.
After runup and takeoff checks are complete and flaps are either up or set to 15˚. The Gipsy Major sounds different than either horizontally opposed or radial engines but produces a satisfying chugging. While you won’t be thrown back in your seat by the acceleration, you will be surprised at how quickly the tail comes off the ground. For that matter, you’ll also be surprised at how soon the Chippie will want to fly! Don’t forget to add LEFT rudder when you lift the nose. Did I mention that the Gipsy Major engine turns counterclockwise? Even though the 145-horsepower engine isn’t producing a lot of torque, the amount of left rudder required is significant thanks in part to the engine mounted four degrees to the right? Why, pray tell, would this be designed into the Chipmunk? The exaggerated need to apply more rudder at low airspeed and high torque better prepares a student for follow-on training in high performance single engine prop planes. This forethought demonstrates how purposeful de Havilland Canada was in their design, using the wealth of knowledge gained from training thousands of WWII airman.
Flight Characteristics: It may take a while to get up to altitude, but once you get there and push the nose over, you’ll find it a very nice aerobatic machine. It’s great visibility and smooth controls also make it easy to learn formation flying. Fuel burn is about nine gallons per-hour and cruises at about 103-mph. It is truly a pleasant flyer and it’s easy to see why there are so many Chipmunk enthusiasts out there.
Landing: This Chipmunk has flying squirrel-like qualities. With a low drag profile and long, tapered wings, the DHC-1 loves to glide. If you’re like me and like a tight approach pattern, it’s easy to end up high on final, even with full flaps. Slipping helps a little but not a lot, due to the small rudder. Both wheel landings and three-point landings are equally easy in the Chipmunk. The wide stance oleo struts make it possible to cushion landings well enough to not even know when rubber meets terra firma.
Wrap-up: Some call the Chippie, the “poor-man’s Spitfire” – and there’s certainly nothing wrong with that! It’s excellent flying qualities that made it great for training continue to make it highly sought after today!
The de Havilland Canada Chipmunk has the qualities that are important for primary trainers, which is why it was used by air forces all over the word for decades. A home-grown Canadian product, it is a perfect airplane to honor the 100th anniversary of the RCAF. Happy Centennial!
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