Please Help! Lateral Axis, Lateral stability, Longitudinal axis and stablility
 

I keep running into circles when these three aspects are intergrated into the same question. Does someone have a clear way of explaining the characteristics of each and how the interlock with each other.

Thankyou for your help.

Lateral stability is stability in roll. But roll occurs about the longitudinal axis. So lateral stability acts about the longitudinal axis.

Longitudinal stability is stability in pitch. But pitch occurs about the lateral axis. So longitudinal stability acts about the lateral axis.

hmm
 

sits here with mouth open and blank look lol, I guess I need a diagram :bored:

Im in the same position. Its the one part of Principals of Flight that i cant grasp:ugh::ugh:

OK let's try again.

Lateral stability is concerned with how an aeroplane responds to disturbances that cause lateral rotations.

What do we call lateral rotation of an aeroplane? Rolling.
So we call roll stabilty Lateral stability.

But what axis do we roll about? The longitudinal axis.

So lateral (or roll) stability acts about the longitudinal axis.


Longitudinal stability is concerned with how an aeroplane responds to disturbances that cause longitudinal rotations.

What do we call longitudinal rotation of an aeroplane? Pitching.
So we call pitch stability Longitudinal stability.

But what axis do we pitch about? The lateral axis.

So longitudinal (or pitch) stability acts about the lateral axis.

A diagram certainly helps and your course notes should contain one.

Buy a model aeroplane and skewer the bloody thing with knitting needles, it'll f**k the model right up, but will clear things in your head!

Regards

CR

P.S will only work if you skewer the thing through the relevant axes. Don't just go stabbing the thing.