hi this is episode 1 in the theory of flight chapter today we'll be going over some basic aviation terminologies this is very important to your understanding of future topics and ideas so make sure you understand this well before moving on to harder topics feel free to comment down below if you have any questions i will be glad to help you so let's get started the first term we'll be talking about is an airfoil an airfoil is a structure curved to produce lift when people talk about airfares they often talk about the wings of the aircraft what's often forgotten is that propellers are also considered airfoils the only difference is that a propeller creates lift forwards and we call that thrust to separate the two forces the next term is the chord line but before that there are still two mini terms that you need to know they are the leading edge and the trailing edge the leading edge is the front of the airfoil and the trailing edge is the end of the airfoil with those definitions in mind we can talk about the chord line the chord line is simply an imaginary line between the leading edge and the trailing edge of the wing as long as you know where the leading and trailing edges are you just need to play connect the dots to find the chord line the next term is camber the camber is the curvature of an airfoil in this diagram you can see that there are three cambers the upper and lower cambers are just the upper curvature and the lower curvature respectively and when you get an average that is the mean camber the fourth term is the wingspan wingspan is the distance measured from wingtip to wingtip this is another easy term again just play connect the dots with the two tips of the wing and you will get the wingspan next up is the wing area the way to calculate the wing area is just by multiplying the average length by the average width a good way to remember this is that is the same as calculating the area of a rectangle the next term is plan form plan form is the shape of the wing viewed from above these are a couple of examples of wing platforms up next is aspect ratio the aspect ratio is the ratio of wingspan to wincord gliders typically have a higher aspect ratio because of their ability to reduce induced drag while aircrafts such as fighter jets have a low aspect ratio for their high maneuvering ability the next term is the angle of incidence this is the angle between the chord line and the longitudinal axis this is important as it defines your optimal takeoff speed do note that on most aircrafts this angle is locked in place so you really can't change it before we talk about the last term in this video let's talk about relative airflow this is the airflow with respect to the wings you can think of this as the airflow opposing to the aircraft's motion when thinking about relative airflow be sure to first ask yourself this what is the aircraft's current motion in situations like stalls although the aircraft's nose is up the aircraft is actually dropping downwards meaning the relative airflow is not a horizontal line and instead in more of a 45 degree angle this is very important as it is crucial to understanding the last term which is the angle of attack the angle of attack is the angle between the chord line and the relative airflow this is a very important idea in aviation as this determines a lot of what you can and cannot do and that concludes this video if you found it helpful please consider liking this video and subscribing to my channel feel free to also comment down below if you have any questions for me i look forward to seeing you in the next video [Music] you