Windshear

Question 1

3 WINDSHEAR detection systems on B777

Answer 1

1) EGPWS (immediate - you are in it)
2) PWS (predictive - it’s ahead of you)
3) You (the pilot)

Question 2

When is it active?

Answer 2

EGPWS - airborne below 1500R

PWS - During take off and airborne below 1200R

You - Always (looking for deviations in speed,v/s,g/s,power etc.)

Question 3

What is the indication?

Answer 3

EGPWS - 2 tone siren followed by “WINDSHEAR, WINDSHEAR, WINDSHEAR”

PWS - “Monitor Radar Display” (Caution) (inhibited at 80kts)

“WINDSHEAR Ahead” or “Go-around WINDSHEAR ahead” (Warning) (inhibited at 100kts)

Question 4

Avoidance

Answer 4

Presence of WINDSHEAR may be indicated by:

• Thunderstorm activity
• Virga
• Pilot reports
• Low level WINDSHEAR alerting system (LLWAS)

Question 5

Precautions

Answer 5

Whenever WINDSHEAR is reported or anticipated that might adversely compromise the take-off and initial climb performance FULL THRUST should be used.

Where conditions indicate the SEVERE WINDSHEAR may be present DO NOT TAKE OFF!

• For optimum take off performance used F20.
• Use the longest suitable runway provided it is clear of know WINDSHEAR.
• Use the flight director after take off