Windshear Knowledge Flashcards
If windshear encountered on take-off or approach, should you tell ATC?
Yes, if it is considered a hazard. Report height and severity.
What is considered severe windshear?
Uncontrollable changes from normal steady flight conditions below 1000AGL, in excess of the following:
- 15 kts of indicated airspeed
- 500 fpm vertical speed
- 5º of pitch attitude
- 1 dot displacement on the glideslope / glidepath
- unusual thrust for prolonged period
Severe windshear is reported / forecast. Can you take off?
No! DO NOT TAKEOFF.
Windshear is reported but severity cannot be determined. Can you use reduced thrust for takeoff?
No, full thrust must be used.
When can you use reduced thrust for takeoff despite windshear being reported?
If the windshear is caused by strong winds and there is not CBs or frontal activity.
You get a GPWS windshear warning – 2 tone siren & “WINDSHEAR, WINDSHEAR, WINDSHEAR” with red WINDSHEAR on PFD. Can you manouvre to avoid?
No, a windshear escape manouvre must be flown.
Are there any circumtstances in which a GPWS windshear warning can be ignored?
Yes. Exceptionally, in conditions of extreme turbulence associated with strong winds and not CB or frontal activity, the windshear warning may be treated as advisory, provided that this warning has been anticipated, briefed for in the approach brief and appropriate allowance made.
What clues can you look for to detect the presence of windshear? (clue: there are 4)
Thunderstorm activity
Virga
Pilot reports
Low level windshear reporting (LLWAS) warnings
What should you do if the presence of winshear is confirmed and there are thunderstorms nearby?
On the ground : delay take off
In the air : do not continue the approach
Windshear (not severe) is reported on takeoff, can you use reduced thrust?
No. Full thrust must be used.
Severe windshear reported before departure, can you take off?
No, do not take off if severe windshear rerported.
What flap setting is recommended for take off in windshear conditions?
F20 unless limited by obstacle clearance and/or climb gradient.
F15 may be used and will provide nearly the same performance as F20.
What flap setting is recommended for landing with windshear reported?
F25 or F30.
What is the only PWS caution?
Monitor radar display
“MONITOR RADAR DISPLAY” aural heard. What do you do?
Manoeuvre to avoid. WEM is an option but will require flying straight ahead which may take you into the shear. Heading select is a good mode choice.
PWS “WINDSHEAR AHEAD, WINDSHEAR AHEAD” aural warnring on take off prior to V1. What should you do?
RTO
PWS “WINDSHEAR AHEAD, WINDSHEAR AHEAD” aural warnring on take off after V1. What should you do?
Unlikely as inhibited above 100kts but perform WEM if during take off roll. If airbourne, manoeuvre to avoid.
PWS “GO-AROUND, WINDSHEAR AHEAD” on approach, what do you do?
WEM is an option, but you are not in it yet so go-around then manoeuvre to avoid with heading select is a better option.
Windshear encountered in flight. You are manually flying.
What do you do?
WEM : 1. Call "Windshear, go-around" 2. Disengage the AP 3. Push TOGA 4. Aggressively apply full thrust 5. Disconnect AT 6. Simultaneously roll wings level & pitch to 15º 7. Retract speedbrake 8. Follow the FD TOGA guidance (if available) ---------------------------------------- Do not change gear or config Monitor vertical speed and altitude Do not attempt to regain lost airspeed until out of it
Windshear encountered in flight. The autopilot is in.
What do you do?
WEM : 1. Call "WINDSHEAR, GO-AROUND" 2. Push TOGA 3. Verify TOGA annunciated on PFD 4. Verify GA thrust 5. Retract speedbrake 6. Monitor system performance ---------------------------------------- Do not change gear or config Monitor vertical speed and altitude Do not attempt to regain lost airspeed until out of it
