What to Do With a Wind Shear Alert When You're Flying
Wind shear is a weather phenomenon not to be messed with. It's a weather condition that can cause turbulence, as well as updrafts and downdrafts. These conditions can equate to a large gain or loss in airspeed and altitude in your aircraft over a very short amount of time, and when low to the ground such as for takeoff or landing, there may not be sufficient altitude with which to recover.
Wind shear is any sudden change in the direction or velocity of the wind over a short distance.
It can be either vertical or horizontal. It can occur at any altitude, but it's most dangerous near the ground.
Wind shear is one of those invisible weather phenomena, similar to wake turbulence, so it's impossible to know where it is or when it's occurring. Today's airport weather technology can wind shear, but the only other way to know that it's there is through pilot reports or PIREPS.
So what would you do if you're flying along and another pilot reports wind shear, or you hear a wind shear alert on the ATIS? That's a tough question. The FAA's guidance says that a single microburst (area of wind shear) can last up to fifteen minutes, but often wind shear conditions last much longer than that. If an airport you're landing at is reporting wind shear or microburst activity, your options are:
Use the most favorable runway, but be prepared for the wind to change.
- Attempt an approach, but be prepared to go around quickly and early if wind shear is detected. Watch for visual signs like dust or debris blowing upward and outward. Watch for early signs of an unstable approach.
- If wind shear was a problem during the first approach, wait a few minutes for it to dissipate before trying again.
- Wait for a few other airplanes to fly the approach and see if they are reporting wind shear conditions or the absence of wind shear conditions.
- Fly to an alternate airport.