How does an aircraft fly?
Although the travel industry took a huge knock during the pandemic, we are hopeful that we will soon be able to jet away to visit different countries again. However, have you ever wondered how an aircraft stays in the air? We caught up with our Technical Training Manager, David Firth, to find out how aircraft fly.
The Physics
There are four forces to consider when thinking about getting an aircraft off the ground, keeping it in the air and landing it safely. The pilot must balance these four forces at each stage of the flight, from take-off to landing, to ensure the aircraft remains stable.
Lift
This helps the aircraft ascend and pushes it up.
Weight
This is the act of gravity pulling the aircraft towards the earth.
Thrust
This accelerates the aircraft, moving it forward
Drag
The wind resistance that slows the aircraft down
We also experience thrust, drag and weight when driving a car. You use thrust to accelerate, drag to slow down and weight keeps your car on the road.
So, let’s start with how the aircraft takes-off…
When you’re buckled up and the safety checks have been completed, the pilot gets ready to accelerate the aircraft down the runway. When you’re taking off the pilot uses thrust from the engines and lift from the air passing over the wings to get the aircraft off the ground and into the sky. The aircraft wing is designed so that the air travelling over the wings is faster than the air travelling underneath the wings, creating high pressure under the wing and low pressure above the wing, which creates lift. The upward force is stronger than the weight of the plane, so it takes off from the ground. As the aircraft moves forward across the runway, the wings move it upward.
During flight
Newton’s third law of motion states: “For every action there is an equal and opposite reaction.” This means that the pilot must work with the weather to know what forces to apply to keep the aircraft stable in the air. It’s like adjusting how you drive based on the weather conditions; you wouldn’t drive fast when there is ice on the road, just like a pilot wouldn’t accelerate through high winds.
How the pilot controls the plane
Throttle
The pilot uses throttle to increase or decrease the power from the engines to increase or decrease thrust.
Ailerons
These raise and lower the wings so the aircraft can turn, it’s also known as the roll of the plane. If you want the aircraft to roll right, then you would raise the right aileron and lower the left aileron.
Rudder
This controls the nose of the aircraft, which also helps the aircraft turn with the ailerons.
Landing the aircraft
Many people find this the most daunting part of flying because you’re descending back down to earth at a fast pace. Landing is similar to taking off, but the pilot uses the opposite forces. Drag and weight are used to descend the aircraft. The aircraft is also designed with landing gear elements to slow down the thrust so you can land safely.
How safe is flying?
Air travel remains the safest form of transport with accident rates as low as 1 in every million departures. The likelihood of being involved in an aviation accident is very low. To put this in perspective, according to MIT, your odds of dying in a road traffic accident is 1 in 14,000, whereas your odds of dying in an aviation accident is 1 in 7 million. Statistically, you are more likely to be killed by a lightning strike or a tornado so, try to remember those statistics if you are a nervous passenger.
Most aviation accidents are caused by human error or equipment failure due to poor maintenance. At Marshall Centre, we deliver world-class aircraft maintenance and human factors training; if it flies, we can train people to maintain it safely!