WINDSHEAR Flashcards
What is the definition of windshear?
A sudden change of wind velocity and/or direction
What are the some of the criteria that would be used to define what is considered as windshear?
IAS variations of more than 15 kts
Vertical speed changes of more than 500 ft/min
Pitch changes of more than 5 degrees
Heading variations of more than 10 degrees
Glideslope deviations of 1 dot
What is the difference between Predictive Windshear and Reactive Windshear?
Predictive Windshear warns ahead of the aircraft and gives guidance to avoid it.
Reactive Windshear gives warning when in the windshear
From where does Predictive Windshear and Reactive Windshear get it’s information respectively?
Predictive Windshear uses doppler weather radar to detect disturbed air.
Reactive Windshear uses a comparison between inertial and aerodynamic data. i.e. is the plane behaving as expected
What is the Predictive Windshear caution aural alert on the ground and in the air?
“MONITOR RADAR DISPLAY”
What is the Predictive Windshear warning aural alert on the ground?
“WINDSHEAR AHEAD” x 2
What is the Predictive Windshear warning aural alert in the air?
“GO AROUND, WINDSHEAR AHEAD”
Through which aircraft system is Reactive Windshear alerted?
GPWS Mode 7
Which computer provides Windshear detection function?
FAC
When is the Windshear Detection function active?
- At take-off, 3 sec after liftoff
up to 1200 ft - For Landing, from 1200 ft
down to 50 ft
CONF 1 has to be selected
From what altitude, on approach, does the PWS system start scanning and when does the alerts start?
Starts scanning at 2300 ft
Alerts start at 1200 ft
How is the Predictive Windshear function turned on?
Operates when the PWS switch is in AUTO
How far out does PWS scan and within what angles?
5 nm out and 30 deg either side
What is the scan distance and angles for PWS Cautions and Warnings up to 100 kts on take-off?
Advisory: Out to 5 nm and 30
deg either side
Cautions: Out to 3 nm and 30
deg either side
Warnings: Out to 3 nm and
0,25 nm either side
What is the scan distance and angles for PWS above 50 ft on take-off and landing?
Advisory: Out to 5 nm and 30
deg either side
Cautions: Out to 3 nm and 30
deg either side
Warnings: Out to 1,5 nm and
0,25 nm either side
When are PWS inhibited?
At takeoff, inhibited from 100 kts to 50 ft
Landing, inhibited from 50 ft
What flap setting is recommended in Windshear and why?
Flap 3
This is to get a better climb gradient on a go-around
What Vapp are you allowed to set manually on a suspected Windshear Approach?
Vls +15 kts
When is RWS system available?
From 3 sec after liftoff to 1300 ft on takeoff
From 1300 ft to 50 ft on approach with minimum Flaps 1
