We discussed what windshear is in Ready For Takeoff Podcast Episode 94. Now we'll discuss pilot procedures to escape windshear encounters.
Windshear predictive equipment is discussed in AC 20-182A.
A recent landing accident at Sochi, Russia highlights the importance of adhering to crew procedures during windshear encounters. As you can read here, the crew made several attempts at landing, and finally landed during windshear and departed the runway, resulting in a hull loss.
The important take-away from this report is that the crew did not adhere to proper windshear avoidance and escape procedures. When the predictive windshear system announces "monitor radar display", it is indicating that there is potential windshear somewhere in the flight path. When it announces "go-around, windshear ahead" it indicates that windshear conditions exist directly in front of the aircraft, and a normal go-around should be accomplished. When the voice announces, "windshear", the aircraft is currently in windshear conditions and the windshear escape maneuver must be accomplished. Depending on the aircraft, the windshear escape maneuver may be totlaly different from a normal go-around.
While a normal go-around usually continues to use the autothrottle system, during a windshear escape maneuver, the autothrottles are disconnected and maximum thrust is required. Additionally, unlike a normal go-around, the landing gear is not retracted (to avoid additional drag of gear doors opening) and the aircraft is climbed at a pitch attitude established by the manufacturer (15 degrees for Boeings). Depending on the effects of the windshear, the crew may be required to decrease the climb to honor the pitch limit indicator.
The key to dealing with windshear is AVOIDING it at all costs, since there may windshear conditions that exceed the performance of the aircraft.
