Figure 4-7. Cross Section of a Microburst

CHAPTER FOUR

AVIATION WEATHER

Figure 4-6 Vortex Ring of a Microburst

Figure 4-7 Cross Section of a Microburst

The wind shear created by microbursts is extremely dangerous to aircraft during the takeoff,

approach, and go-around phases of flight. Not all microbursts are associated with thunderstorms.

Microbursts are possible with any rain shower, even if the rain isn't reaching the ground (virga).

In Figure 4-8, the aircraft at position 1 has entered a microburst. At this point, the crew may

notice an increased angle of attack as the aircraft enters the upward flow of the vortex ring.

Once inside the microburst, the aircraft will experience a strong increase in headwind, with a

resulting increase in indicated airspeed and lift, which will cause the aircraft to pitch up (position

2). A natural reaction of the pilot would be to reduce power and apply nose down stick force.

This would correct the situation if the aircraft was not in a microburst, and would appear to work

4-8

Thunderstorms