Microburst recovery and avoidance

Hazard sequence on takeoff or approach (TC AIM AIR 2.8, PHAK ch.12):

1. Increasing headwind: airspeed/performance UP
2. Downdraft
3. Rapidly increasing tailwind: airspeed/performance DOWN

• Sudden tailwind near ground = airspeed decrease and lift loss (TP 13014 sample exam Q42 key; AWH 22.7.3).
• Reducing power and lowering nose to counter headwind shear leaves nose-low and power-low when tailwind shear arrives: risk of stall or landing short of runway (AWH 22.7.3).

Recovery (TC AIM AIR 2.8, AWH 22.7.3.1):

• Hold or increase pitch; accept lower-than-usual airspeed.
• Do not lower nose to chase lost airspeed: wastes available performance, costs altitude.
• In all aircraft, recovery could require full power and pitch attitude consistent with maximum angle of attack.
• Some encounters cannot be escaped by any known technique (AWH 22.7.3).

Avoidance:

• Best defence: avoid it (TC AIM AIR 2.8).
• Watch for signs early on approach; go around at first indication, as recovery may be impossible at low altitude (AWH 22.7.3).
• Onboard systems (TC AIM MET 2.3):

Trap: lowering nose to regain airspeed in wind shear. Burns performance margin; hold or raise pitch, accept lower airspeed.

Practice