Video: The Effects of CG on an Aircraft

by Jason Schappert

Let’s face it, understanding how an aircraft’s center of gravity position effects things like stall speed or cruise performance is tough. Whether a CG is more aft or more forward makes all the difference in the world! Follow along with me as I shed light on this subject. Remember this one is a tough one so don’t hesitate to watch it twice or ask a question below!

Download the Flightbag Note Card mentioned in the video here: How CG Effects Aircraft Performance

http://makingtimeforflying.blogspot.com/ Julien

Hi Jason,

Thanks for this video and for all the previous ones too, I’m always learning something new!

I was a bit confused though by the part of this video that shows the CG in relation to the Centre of Lift (CL). If I compare the diagram at 1:56 in the video (aft CG) with the diagram at 2:18 (forward CG), I get the impression (looking at which direction the yellow arrows expands) that the CG moves from one side of the CL to the other.

My understanding is that this does not correspond to reality, where (at least in common GA airplanes) the CG is always forward of the CL, which is obvious from the see-saw diagram later on in the video. Did I miss something?
http://makingtimeforflying.blogspot.com Julien

Hi Jason,

Thanks for this video and for all the previous ones too, I’m always learning something new!

I was a bit confused though by the part of this video that shows the CG in relation to the Centre of Lift (CL). If I compare the diagram at 1:56 in the video (aft CG) with the diagram at 2:18 (forward CG), I get the impression (looking at which direction the yellow arrows expands) that the CG moves from one side of the CL to the other.

My understanding is that this does not correspond to reality, where (at least in common GA airplanes) the CG is always forward of the CL, which is obvious from the see-saw diagram later on in the video. Did I miss something?
http://www.JasonSchappert.com/ Jason Schappert

Julien,

Thanks for the kind words! Awesome comment and question!

First off for those wondering Center of Lift and Center of Pressure are two terms used somewhat interchangeably.

What that yellow line in both instances is showing is the distance between the Center of Gravity and the Center of Pressure.

This was done clearly to show a point. Or an extreme Forward or Aft CG. Never would such an instance occur in a General Aviation aircraft (I hope) But I designed it like that to drive home the point and show the relationship and difference between the two.

So long story short you’re correct! Very good point!

-Jason
http://www.JasonSchappert.com Jason Schappert

Julien,

Thanks for the kind words! Awesome comment and question!

First off for those wondering Center of Lift and Center of Pressure are two terms used somewhat interchangeably.

What that yellow line in both instances is showing is the distance between the Center of Gravity and the Center of Pressure.

This was done clearly to show a point. Or an extreme Forward or Aft CG. Never would such an instance occur in a General Aviation aircraft (I hope) But I designed it like that to drive home the point and show the relationship and difference between the two.

So long story short you’re correct! Very good point!

-Jason
Eurofighter336

Any way to download videos, are the videos free?
Anonymous

Of course they’re free! My only paid content is my online ground school videos.
Armored Angel

Thanks for the video!! Very helpful. I agree…C.G. is one of the harder topics. I am a commercial applicant and I still have to stop and think for a second about C.G. effects. It is definitely important to know these effects and limitations of your aircraft.
Soheil Spirit

very nice video…thx
Troy

A solid explanation, with nice illustrations.