Why don’t you feel takeoff as much in a larger airplane? The Physics of the larger airplane’s smooth takeoff.
There are many advantages to flying in smaller airplanes: they tend to zip in and out of airports quickly, go around larger planes and squeeze into airport gates better, they can land in smaller cities or islands with shorter runways and they are generally more flexible than your typical jumbo jet. But with the perks come disadvantages – particularly when it comes to taking off.
While it is easy to miss the jump into the sky on a jetliner, those flying on a small plane will feel every bump and lift as the plane soars into the air. Theoretically, liftoff should feel the same regardless of what size airplane you’re on. Passengers may chalk up a smooth or rough takeoff to the skill of the pilot, but Captain Zap Mapua, longtime international long haul pilot with Philippine Airlines, disagrees. “Pilots and their flying experience can make some difference,” he said. “But the takeoff procedures are rigid, making pilot differences pretty small.”
Instead, the reason you don’t feel takeoff as much in a larger plane boils down to the laws of physics and the design of the airplane itself. “There are many factors that cause the difference in the sensation,” said Mapua, including aerodynamics, engines and tires.
First a bit of aeronautical engineering: Planes are able to take off and fly through the air thanks to a combination of engines (either jet or propeller) that thrust the plane forward and perfectly engineered wings that provide lift. As NASA explains, how much lift the plane gets depends on the shape, size, and weight of the airplane as well as the speed at which it is moving. ”Large airplanes have more mass—they weigh more— and, therefore, accelerate slower,” explained Mapua. Slower acceleration can result in a lift-off that feels smoother.
Another reason takeoff on a large plane is easier on the body is due to the number of engines on a jumbo jet. Most commercial airplanes have four engines, while smaller planes run on two. While you might think that more engines would translate to greater velocity and thrust and a smoother takeoff, the weight of the plane plays a big role in lift-off too.
“Large four-engine airplanes (like the double-decker Airbus A380) climb slower than modern twin jets,” explained Mapua. ”With a four-engine airplane there are three other engines to provide thrust for the climb, in a twin there is only one other. This means that twin jets have a higher power-to-weight ratio than three or four engine jets.”
Think of this like a motorcycle versus a car. Motorcycles are stripped down to two wheels and a seat, while a car has four seats, four doors and windows. They may have similar engines, but a motorcycle’s reduced weight allows it move faster. That sounds ideal, until you hit a pot hole, which you will feel a lot more on a motorcycle than in your average sedan. It’s the same with airplanes: smaller planes may be able to move faster, but you will feel all the bumps. “Because the large airplanes weigh more, they are not affected by air turbulence as much,” added Mapua.
There may also be some differences in the landing gear between a larger and smaller plane. “Large jets have more tyres making it a little more stable – with the tyres absorbing the bumps on the tarmac or runway; but this is a small difference”.
Mapua also attributes part of an easier takeoff to a visual trick. “Passengers are further away from the ground, because large airplanes sit higher, making the visual sensation less intense”, comparing the experience to something like riding in a sports car versus riding in a bus. Even though the commuter bus and, say, the Ferrari are driving the same speed, the feeling is more intense in a sports car since it is lower to the ground. It’s a similar experience in a small airplane where your eyes trick your brain into feeling like a takeoff is more intense than in a large plane, when it’s objectively more-or-less the same thing.
“Do not go where the path leads, travel instead where there is no path and leave a trail.” @wbbrjp