Fokker Dr.I Triplane

Fokker Triplane taxiing out for a takeoff

Fokker Triplane taxiing out for a takeoff

The Fokker Dr.I triplane is one of the most recognizable aircraft from World War I. With its distinctive three wing layout as well as being one of the favored aircraft of the famous German ace Manfred von Richthofen, the Dr.I makes for a fascinating historical aircraft and an ideal radio control modeling subject.

The Fokker triplane was built in response to the appearance of the Sopwith Triplane in 1917. The use of three wings was an attempt to create a more maneuverable fighter aircraft compared to the more prevalent biplanes.

Side view of the Fokker Triplane

Side view of the Fokker Triplane

Aircraft could be prototyped and flown in a very short period of time due to simple wood and fabric construction and the lack of any electrical system. Fokker created an initial variant that showed promised and a finalized Dr.I was first flown on July 5, 1917.

The Fokker Dr.I was advanced for the time in that it employed thick cantilever (self-supporting) wings that did not require external rigging wires. Flight tests showed the need for a single interplane strut on each side to minimize wing flexing.

The Fokker triplane was pronounced a success by von Richthofen and entered operational service in early 1918. Von Richthofen flew this aircraft for his last 19 aerial victories and was killed in a Dr.I on April 19, 1918.

The design objective of the Fokker triplane was maneuverability as opposed to speed. The thick airfoil section of the three wings offered a lot of drag but at the same time a tremendous amount of lift.  The plane could turn quickly and presented a difficult target for Allied fighter pilots to track and attempt to shoot down.

The Dr.I had a narrow landing gear and fixed tail skid (i.e. no tail wheel) thus was tricky to handle on the ground. You’ll note in the video the Triplane takes off in a very short distance.  The Triplane’s challenges with ground handling required all takeoffs and landings be headed directly into the wind.  Thus the term “airfield” as the landing direction was dictated by the wind and aircraft did not require much landing distance due to their low speeds.  Longer paved runways would come a few years later in response to higher performance aircraft.

Detailed wood framework of a Fokker Triplane model

Detailed wood framework of a Fokker Triplane model

Another key insight regarding the challenges of flying the Fokker Triplane lay with the use of a rotary engine. Rotary engines were in common use during World War I.  The design was complex as the cylinders rotated around a fixed crankshaft but offered a lot of thrust for the time.  This is the direct opposite design approach of the later and more common radial engine, where the cylinders are fixed in place and the crankshaft rotates.

Rear view of a nicely done Fokker Triplane RC model

Rear view of a nicely done Fokker Triplane RC model

One difficulty with a rotary engine is that there is no easy way to throttle the engine. Once it is running you are essentially at full power.  Pilots could “blip” the ignition off and on in the landing pattern to effect a small reduction in thrust.  But for takeoff the pilots relied on a ground crew to hold the plane in place, and once released off they went into the air.

The Fokker Dr.I truly is a small aircraft. For example, the wingspan is a mere 23 feet 7 inches.  A Cessna 150 has a wingspan of 33 feet.  The Triplane’s empty weight is 895 pounds; a Cessna 150 has an empty weight of 985 pounds.

The small size made the Dr.I made it extremely difficult to see in the air which was a huge advantage to the German pilots. Recall that no World War I aircraft had an electrical system, thus no radios.  When a pilot took off they were truly alone.  No wingman could call out an enemy aircraft sighting and no ground controller could warn of distant threats. Each pilot needed to individually sight a combatant aircraft and engage.  A single missed visual contact could result in death.

An interesting side note on the Triplane’s small size is the placement of the machine guns on the aircraft’s nose. There was barely enough room for the guns, and the back end protruded into the cockpit.  This was a problem during any forced landing as the pilot could get a head injury.

Eventually the Dr.I’s lack of speed combined with structural weaknesses that resulted in several crashes forced the Germans to retire the design in May 1918 in favor of the much superior Fokker D-VII biplane. A total of 320 triplanes were built.

Full size Fokker Triplane view from below. Note conventional engine.

Full size Fokker Triplane view from below. Note conventional engine.

And as you can see in the video parachutes were not worn by the majority of pilots. Balloon observers had then installed in their crew baskets.  This was a result of balloons being a sitting target that got shot down on a continual basis.

German pilots used parachutes in the closing months of World War I. The Royal Air Force did not permit the use of parachutes for their pilots as the RAF leadership was concerned that pilots would show a lack of resolve and bail out rather than face aerial combat.  As sad and difficult to comprehend this may seem to us today, such was the military thought process at the beginning of the last century.

A final note must be offered regarding the comradery between Allied and German pilots in that early era of flight. Both sides knew the unforgiving nature of aerial combat and the inherent risks involved.  The film shows a remarkable gathering of German pilots with a British aviator, presumably shot down earlier.  It is almost unthinkable this type of interaction would occur today.