Where is the datum of an aircraft located?
The horizontal reference datum is an imaginary vertical plane or point, placed along the longitudinal axis of the aircraft, from which all horizontal distances are measured for weight and balance purposes. There is no fixed rule for its location, and it may be located forward of the nose of the aircraft.
What is the datum on an airplane?
reference datum
Datum (reference datum)—an imaginary vertical plane or line from which all measurements of arm are taken. The datum is established by the manufacturer. Once the datum has been selected, all moment arms and the location of CG range are measured from this point.
What’s the difference between a forward and aft CG?
Whether the CG is aft or forward refers to its position along the longitudinal axis of the airplane, that axis that runs from the aircraft nose to the tail. Usually if people refer to just “the CG” they’re typically referring to the longitudinal position of the CG as that is generally the most critical.
What makes a plane more stable forward or aft?
Stability is already explained pretty well in What does it mean for a plane to be aerodynamically stable?. The summary is that forward centre of gravity makes the aircraft more stable, but slightly less efficient, while aft centre of gravity makes it less stable.
What happens when an aircraft is in a forward CG position?
With a forward CG position, although the stability of the aircraft increases, the elevator control authority is reduced in the capability of raising the nose of the aircraft. This can cause a serious condition during the landing flare when the nose cannot be raised sufficiently to slow the aircraft.
What happens when you load an airplane to the aft CG?
Loading an airplane to the most aft CG will cause the airplane to be A—less stable at all speeds. B—less stable at slow speeds, but more stable at high speeds. C—less stable at high speeds, but more stable at low speeds. Loading in a tail-heavy condition can reduce the airplane’s ability to recover from stalls and spins.