At my current base, I offered to write a monthly “Ask an Engineer” column, where base clinicians write in with questions on helicopter design and engineering, and I answer them. This is my first column:
Why do helicopter pilots sit on the right, while airplane pilots sit on the left?
The short answer is because that’s what pilots are already used to, and any new aircraft are designed to fit current pilot preferences. That begs the question, though: how did each tradition get started, and more importantly, why are they different between helicopters and airplanes? There’s no generally accepted single answer in either case, but a combination of the following is most likely:
Modern airplane design conventions first appeared in the 1920’s and 30’s. During that time, most airplanes were powered by large nose-mounted single engines and propellers. Most engines at the time rotated such that their torque made it difficult to turn the airplane to the right on the ground, which meant that pilots preferred to make ground taxi turns to the left. Also, most airplanes during this time had tailwheels, and sat (and taxied) nose-high. Pilots therefore preferred (so airplane manufacturers designed) airplanes in which pilots sat on the left, so they could see best in the direction they were most likely to turn on the ground.
There were aerial navigation reasons for pilots to prefer sitting on the left side, as well. Navigation at that time was mostly done by flying between visual ground checkpoints (bonfires, in the early days!), and it was convention for pilots to fly on the right side of those checkpoints, so as to stay clear of pilots using the same ones going the opposite direction. Most airport traffic patterns utilized left turns, as well. Flying on the left side, then, give the airplane pilot the best field of view to look for other air traffic near checkpoints and airports.
Helicopters became commercially viable later, in the 1940’s, and that’s when their design conventions began to solidify. The first mass-produced helicopter was the Sikorksy R4. It had two seats, and was originally designed to be flown from the left seat, perhaps to match already-established airplane design conventions. The test pilots for the aircraft were its first instructors, and mostly flew it from the left seat, and therefore their trainees mostly all learned to fly it from the right. The test/instructor pilots trained many more pilots than they themselves numbered, so the preference among early helicopter pilots (around which, again, the manufacturers designed) was to sit on the right.
Another potential reason for the start of the tradition was the location of the helicopter’s controls. In order to save weight and reduce complexity, early two-pilot helicopters like the R4 had only one collective control, in between the pilots. Most pilots are right handed, and preferred the control that required more finesse (so the cyclic control) to be manipulated by their dominant hand, which meant that they preferred to sit on the right.
The previous are the most likely reasons why pilots sit where they do now, but there are some interesting modern exceptions to this convention. The most common of these is the Airbus H130 (previously Eurocopter EC130), in which the pilot sits on the left. The reason for this is that, though it’s widely used in helicopter EMS these days, the H130 was originally designed as a tour helicopter. Eurocopter extensively solicited tour operator input during the design process, and one of the things the operators told them was that in helicopters then used for tours (predominantly the AS350 AStar and B206 JetRanger/LongRanger), some front-seat passengers, attempting to enter the aircraft, would grab anything that looked like it might be useful in pulling themselves into the helicopter, including the collective! Grabbing onto it while getting inside raised the collective, causing some inadvertent (near-) takeoffs, and the operators wanted to eliminate this risk. Eurocopter felt the best solution to this problem was to move the pilot seat to the left side of the aircraft, where the collective would be near the pilot door, as opposed to between the pilot and front seat passenger. This design change worked well for tour operators, and pilots transitioning between left- and right-seat helicopters have not found it difficult to do so, so we may see even more left-seat piloted helicopters in the future.