Wind Shear and Microbursts
Recognizing the invisible killer and surviving an encounter
No Aircraft Can Out-Perform a Severe Microburst
A microburst can produce downdrafts exceeding 6,000 fpm—more than any aircraft can outclimb. The only defense is avoidance. If you encounter a microburst at low altitude, survival depends on luck and immediate, aggressive recovery technique.
Understanding Wind Shear
Wind shear is any rapid change in wind velocity—speed, direction, or both—over a short distance. When you fly through wind shear, your aircraft's indicated airspeed changes suddenly because the air mass around you has different motion than the air you just left. This creates immediate changes in lift and can drive you toward the ground.
Wind shear is most dangerous near the ground where you have no altitude to recover. During approach, an aircraft configured for landing with gear and flaps down has limited energy available. A sudden loss of airspeed can push the aircraft below the approach path with insufficient power to recover before impact.
Anatomy of a Microburst
4,000-6,000+ fpm
increases lift
ZONE
decreases lift
The deadly sequence on approach:
- 1. Aircraft enters headwind outflow—airspeed increases, aircraft balloons above glidepath. Pilot reduces power to correct.
- 2. Aircraft enters downdraft core—rapid descent rate, altitude loss despite pitch-up.
- 3. Aircraft exits into tailwind outflow—airspeed drops 30-50 knots instantly, approaching stall with insufficient altitude to recover.
The pilot who reduced power in step 1 (a normal reaction) has made the situation worse. By the time they recognize the microburst in step 2-3, recovery may be impossible.
Recognition Cues
Visual Indicators
- • Localized dust/debris cloud on surface
- • Rain shaft curving outward near ground
- • Virga (precipitation not reaching ground)
- • Ring of dust spreading from a point
- • Trees/grass suddenly bending outward
- • Nearby thunderstorm or heavy rain
Flight Deck Indicators
- • Sudden airspeed increase then rapid decrease
- • Excessive sink rate despite pitch-up
- • Indicated airspeed/groundspeed divergence
- • GPWS/TAWS "WINDSHEAR" alert
- • Predictive windshear system warning
- • ATC reports from preceding aircraft
METAR Wind Shear Reports
KDFW 161853Z 18012G25KT 10SM FEW045CB SCT250 32/19 A2987 RMK AO2 WS020/18045KT
WS020/18045KT means wind shear at 2,000 feet AGL with wind from 180° at 45 knots. This indicates significantly different wind than the surface observation (180° at 12G25), warning of shear on approach/departure.
Wind Shear Recovery Procedure
Immediate Actions - MEMORIZE
-
1
THRUST/POWER - MAXIMUM
Firewall the throttle(s). Do not hesitate.
-
2
PITCH - 15° NOSE UP (initial)
Rotate to escape attitude. Adjust as needed to arrest descent.
-
3
SPEEDBRAKES/SPOILERS - RETRACT
Any drag reduction helps. Check these are stowed.
-
4
CONFIGURATION - DO NOT CHANGE
Leave gear and flaps as they are. Changing takes time and attention.
-
5
STICK SHAKER - FLY THROUGH IF NECESSARY
Accept stall warning to maintain escape pitch. Controlled flight into terrain is worse than a stall warning.
This recovery is aggressive for a reason. Studies show pilots who hesitate or make half-measures don't survive microbursts. The goal is to fly out of the shear as quickly as possible, trading airspeed for altitude if necessary.
Avoidance Strategies
If thunderstorms are within 15 nm of the airport, wait for them to pass.
Low Level Windshear Alert System provides surface-based detection at major airports.
Half the gust factor (e.g., if wind is 15G25, add 5 knots to approach speed).
ATC can tell you about ride quality on approach—ask specifically.
If anything seems wrong on approach, execute missed approach immediately.
Key Takeaways
- Wind shear kills because it's invisible and strikes at low altitude
- Microbursts produce unsurvivable downdrafts—avoidance is the only defense
- Recovery: MAX power, 15° pitch, retract spoilers, don't reconfigure, accept stick shaker
- Stay away from airports when thunderstorms are within 15 nm