If the airplane is in straight-and-level cruising flight and a sideward gust impacts it, the tendency is to create a yawing motion about the vertical axis, into the relative wind
, also known as a "skid." This tendency is dampened by increased aerodynamic pressure on the vertical stabilizer from the gust, which resists the yaw.
The gist of it all is an airplane usually doesn't care from which direction the wind is blowing, except when abrupt changes to the relative wind
are made, regardless of whether they result from pilot input, encountering gusts, or both.
Think of a single (or a twin with both fans turning) in a sideslip--drag is dramatically increased when the airplane is "sideways" to the relative wind
. In a single, the "fix" is to use rudder to center the ball in the turn-and-bank indicator/turn coordinator's inclinometer.
A strong upward gust associated with a thunderstorm or frontal weather condition (e.g., upward speeds 50 to 75 feet/sec) and striking the aircraft's wings from below causes the relative wind
to change to an upward direction as it meets the wings.
Neal Wynn II, said the right wing tip appeared to move about 24 inches from the normal position, and the right aileron was moving freely in the relative wind
. The crew immediately checked the flight-control-system (FCS) page and saw no abnormal codes or flight-control failures, indicating a probable structural failure rather than an FCS or other system problem.
I realized the graphics did not apply to crosswind landings as the graphics do not show ground track, they show the effect of slips in relation to the relative wind
and direction of flight.
When we talk about how density altitude affects aircraft performance, we generally think of how the wing interacts with the relative wind
: Since the air's less dense, there's less relative wind
, less lift and less performance.
The OOD on the bridge immediately turned the ship to use the relative wind
to direct the flames away from the flight deck and marked the plane's crash site by ordering strobe lights into the water.
Instead of flowing smoothly along the upper surface of the wing, the air simply continues in the direction of the relative wind
. Sometimes called flow separation, this can be visualized by tufting a wing and flying it close to its critical angle of attack.
Each time we came around into the relative wind
, in a right turn, the left float bag started banging around like it was going to rip off the aircraft.
Of course, AOA is the angle formed between the chordline of the wing and the relative wind
into which it flies.
The angle of attack (the "alpha") is the angle between the relative wind
and the chord of the airfoil.