What are the flight characteristics a drone have and how they matter?

In addition to understanding the individual elements, it’s equally vital to grasp flight characteristics to be told however drones work.

Coming from a billboard heavier-than-air craft pilot background, i'm terribly shocked by the amount of RC hobbyists that don't perceive even the foremost basics of flight dynamics and the way drones work.

The goal with any flying craft is equalisation the four totally different principals of flight. These are: carry, weight, drag, and thrust.

For any craft to depart Earth, carry and thrust must be bigger than weight. within the case of the heavier-than-air craft on top of, carry is achieved through the rotor system. If you set an excessive amount of weight within the heavier-than-air craft, there won't be enough power within the rotor system to beat the burden. Thrust is generated through the facility plant and overcomes the force of drag.

In a multirotor, this can be basically happening on every separate motor/propeller system. If there's an excessive amount of weight, flight performance goes to require a serious hit. The lighter the system is, the longer flight time and better performance characteristics it'll have. However, the goal for several is to hold significant cameras and alternative instrumentation. To make amends for this, stronger motors and propellers must be superimposed. The frame must be ready to support that weight in addition.

The same principals that heavier-than-air craft pilots mind, conjointly must be minded by multirotor pilots. however several are uneducated, inflicting excess crashes or significant strain on their frame/parts. the foremost obvious associate degreed basic example has an understanding of however wind affects flight performance.

Airspeed vs. Ground speed

This is one among the additional basic ideas, however extraordinarily vital to grasp. a part of the carry equation is rate. rate is square, showcasing its importance.

Lift = Cl * 1/2P * v^2 * S

Lift = constant of carry * 1/2 Density * rate square * extent

Coefficient of carry = is that the angle of attack and form of the wing.

Density = density of the air and conditions being flown in.

Velocity = velocity of the wing through the relative wind.

Surface Area = extent of the wing.

Take note that rate is measured in velocity, not ground speed. velocity is that the speed of the air striking the vanguard of the wing or mechanical device. This velocity is that the most significant a part of the carry equation.

So what's the distinction between ground speed and airspeed?

Let’s use a automobile for this instance. If you’re driving on the interstate going 75mph, your velocity would be 75mph, obviously. however what's your airspeed? In alternative words, what's the speed of the air if you stick your hand outside the window going 75mph? It’s a trick question, while not knowing the wind speed and direction, it’s not possible to grasp.

On a zero wind day, absolutely calm, the velocity would even be 75mph. however what if you had a 20mph head wind. the bottom speed would still be 75mph, that's unchangining, however the velocity is 75mph + 20mph (wind) = 95mph. we have a tendency to wouldn’t be obtaining superb fuel consumption rate anymore…

Opposite is true with a 20mph tail wind. Ground speed is 75mph, however currently the velocity is 55mph. currently we have a tendency to are becoming higher than traditional fuel consumption rate.

This example is true for aviation. the sole distinction is that velocity is staying the identical, and ground speed is ever-changing. heavier-than-air craft pilots have associate degree velocity of best carry, typically around sixty knots. they're visiting fly that speed to climb to altitude no matter what the wind is doing. however on a twenty knot air current day, there velocity is currently forty knots. In contrary, that twenty knot current of air would offer them a eighty knot ground speed. The distinction between having a twenty knot current of air or air current changes the velocity from forty to eighty knots, pretty massive distinction. currently assume that heavier-than-air craft is coming back in to land at the structure for the day, they might a lot of rather are available and land with a forty knot ground speed versing eighty knots. it's merely a lot of safer.

So what happens once that heavier-than-air craft pilot is coming back in to land unwittingly in an exceedingly tail wind? it would be an entire accident, however the pilot can look outside and see they're going in no time and need to prevent additional. they'll still prevent, and if they aren’t careful, might come back extraordinarily near stall. stall a heavier-than-air craft could be a very little totally different than stalling a plane, however we have a tendency to don’t have time for those details.

The same issue will happen in an exceedingly multirotor. In sturdy winds, if your flight patterns don’t have you ever coming back in to land facing a air current, you may have serious issues. have you ever ever questioned why your multirotor shakes coming back in to land sometimes? Most the time you're most likely extraordinarily near stall.

Now the important fantastic thing about a multirotor is that there's no real “forward” direction. therefore most significantly, once creating your final approach, take care your forward movement is into the wind. Newer drones have plenty of algorithms in-built that they'll build complete vertical approaches. they'll shake, and sometimes it may be violent, however they're designed to accomplish this. However, this is able to are terribly dangerous apply years back before DJI and alternative firms extremely fine tuned these algorithms. there have been more crashes from incorrect landing patterns long ago.

What these DJI algorithms try to make amends for could be a method known as “Vortex Ring State.” this can be one thing you learn on day one after you become a heavier-than-air craft pilot. The downward air from the propellers creates downwash (turbulent disturbed air), and through a fast descent, you're downward into that downwash. it's terribly arduous to make carry during this air, and in an exceedingly heavier-than-air craft, it might produce associate degree uncontrollable descent. The longer you sit during this air, the more durable it's to endure it. the sole resolution of Vortex Ring State is to induce into clean air. Aka, lateral movement. whereas flying your drone, if it ever starts shaking terribly violently in an exceedingly descent, simply roll it laterally into clean air and it ought to solve your downside. Or develop higher descent habits and don’t build vertical descents ;).

As for me, i favor to take care of smart forward velocity, whether or not it’s not entirely necessary all the time. it would save ME some day if I’m not taking note and build a downwind approach once it’s 20mph wind. It may be a chic mistake that i will be able to try and avoid through habit.