> Both forward and sideslips involve opposite aileron and rudder input. In a forward slip (typically used to increase drag and decrease altitude), the aircraft’s nose points away from the direction of flight, with the lowered wing facing the direction of flight. In a sideslip (typically associated with the final stage of a crosswind landing), the aircraft’s nose points in the direction of flight, regardless of which wing is lowered.
and
> To understand the difference between a forward and a sideslip, we need to understand the slip in general. A slip, at its core, is an uncoordinated turn. In other words, when the ball of the turn coordinator is not in the middle, you’re in a slip.
So in general, a slip is a situation where you're banking, but not turning, due to opposite inputs to ailerons and rudder (i.e. between stick and pedals).
As I read through all that, I thought I was coming to a decent understanding. However, finally,
> The jargon is unnecessarily confusing – you move forward during a forward and a sideslip, but you don’t move sidewards during a sideslip; you technically move sidewards during a forward slip!?
It’s use case specific. And depends on perspective.
Forward slip is mainly used to lose altitude without increasing airspeed, such as emergency descent or when too high on approach for landing.
Side slip is mainly used to maintain lateral alignment with runway centerline during a crosswind landing.
The side slip is predicated on a crosswind, properly done the two forces equal. In effect like “leaning a shoulder into the cross wind” to stay laterally and longitudinally aligned with the runway.
Does a turn require a curve in the airplane’s direction? What exactly constitutes a turn? If a plane is in a bank, there is a horizontal component of lift. But if there’s no change in direction (either heading or ground track) is it a turn?
While there is such a thing as a slipping turn, it means an (insufficient) change in direction for the bank angle. If the rate of turn is zero, it’s just a slip.
Conversely I don’t see how you get a skid without a turn.
Here are a few key selections from https://pilotinstitute.com/forward-slip-vs-sideslip/
> Both forward and sideslips involve opposite aileron and rudder input. In a forward slip (typically used to increase drag and decrease altitude), the aircraft’s nose points away from the direction of flight, with the lowered wing facing the direction of flight. In a sideslip (typically associated with the final stage of a crosswind landing), the aircraft’s nose points in the direction of flight, regardless of which wing is lowered.
and
> To understand the difference between a forward and a sideslip, we need to understand the slip in general. A slip, at its core, is an uncoordinated turn. In other words, when the ball of the turn coordinator is not in the middle, you’re in a slip.
So in general, a slip is a situation where you're banking, but not turning, due to opposite inputs to ailerons and rudder (i.e. between stick and pedals).
As I read through all that, I thought I was coming to a decent understanding. However, finally,
> The jargon is unnecessarily confusing – you move forward during a forward and a sideslip, but you don’t move sidewards during a sideslip; you technically move sidewards during a forward slip!?
Hmn.