WINDSHEAR (FCOM-PRO-ABN-80 P80, QRH-ABN-80.15 OM B 2.3.90.10)
A red flag "WINDSHEAR" is displayed on each PFD associated with an aural synthetic voice "WINDSHEAR" repeated
three times. If windshear is detected either by the system or by pilot observation, apply the following recovery technique:
¦ At take-off:
* If before V1:
The takeoff should be rejected only if significant airspeed variations occur below indicated V1 and the pilot decides that there is sufficient runway remaining to stop the airplane.
* If after V1:
Announce: "WINDSHEAR TOGA"
THR LEVERS TOGA
REACHING Vr ROTATE
SRS ORDERS FOLLOW
Airborne, initial climb or landing:
Announce: "WINDSHEAR TOGA"
THR LEVERS AT TOGA SET OR CONFIRM
AP (if engaged) KEEP
SRS ORDERS FOLLOW (This includes the use of full back stick, if demanded.)
Note:
1. If engaged, the autopilot disengages when is greater than prot.
2. If the FD bars are not available, use an initial pitch attitude up to 17.5° with full backstick, if necessary. If needed, to minimize the loss of height, increase this pitch attitude.
DO NOT CHANGE CONFIGURATION (SLATS/FLAPS, GEAR) UNTIL OUT OF SHEAR.
CLOSELY MONITOR FLIGHT PATH AND SPEED.
RECOVER SMOOTHLY TO NORMAL CLIMB OUT OF SHEAR.
WINDSHEAR RECOVERY
The best defence against a windshear encounter is to avoid it in the first place. A pilot should
use his knowledge and experience combined with weather reports to assess the possibility of
encountering windshear and plan accordingly. The weather radar may also be a useful tool as
windshear is often associated with thunderstorms and microburst. The use of managed speed
and the groundspeed mini function will give added protection against windshear in strong winds.
The A320 is fitted with two types of Windshear Protection;
REACTIVE WINDSHEAR:
The FACs generate the windshear warning whenever the predicted energy level for the aircraft
falls below a predetermined threshold.
The protection envelope is from just after lift-off until 1300ft on take-off and from 1300ft to 50ft
for landing. For both cases, at least CONF 1 must be selected.
A red "WINDSHEAR" flag is displayed on each PFD (for a minimum of 15 seconds) associated
with an aural warning "WINDSHEAR" repeated 3 times. If windshear is detected either by the
system or by pilot observation, the pilot must take immediate action:
• Apply TOGA
• Call "WINDSHEAR TOGA"
• Follow SRS orders closely (keep A/P if engaged)
• DO NOT change the aircraft configuration
If the flight directors are not available, then the pilot should pitch up to 17.5° nose up. Should thpilot require it, the use of full back sidestick is available. This may trigger Alpha Floor protection
Both pilots should monitor the Pitch, IAS, V/S and the actual W/V during the encounter, as theyare a good indication of the aircraft’s energy state.
In the unlikely event of encountering windshear during the take-off roll, the takeoff should only brejected if significant airspeed variations occur below V1 and the pilot decides that there is
sufficient runway remaining to stop the airplane. Due to changes in the acceleration of the
airplane during a windshear incident, an overrun may occur if a rejected take-off is actioned.
PREDICTIVE WINDSHEAR:
The weather radar has a Predictive Windshear System (PWS) that scans the airspace ahead of
the aircraft up to a range of 5 miles ahead for windshears. The PWS system detects any
‘Doppler shift’ in the pattern of rain droplets and so will not detect windshears in dry atmospheric
conditions.
The protection envelope available for alerts is from the start of the take-off roll up to 100kts, and
then from 50ft to 1500ft and from 1500ft to 50ft for landing.
When the system detects a windshear, a Warning, Caution or Advisory is triggered.
Warning:
On the PFD: ‘W/S AHEAD’ in red.
On the ND: Windshear icon.
Aural warning: on take-off: "WINDSHEAR AHEAD" twice.
on landing: "GO-AROUND WINDSHEAR AHEAD".
Pilot action: on take-off: Reject take-off.
when airborne: Thrust levers TOGA and turn to avoid the windshear icon.
Follow SRS and normal clean-up provided windshear is not entered.
(On landing, if a positive verification is made that no hazard exists,
the warning may considered cautionary – otherwise go-around.)
Caution:
On the PFD: ‘W/S AHEAD‘ in amber.
On the ND: Windshear icon.
Aural warning: "MONITOR RADAR DISPLAY"
Pilot action: Apply precautionary measures as indicated in ‘FCOM -Supplementary
techniques’
Advisory:
On the PFD: Nil.
On the ND: Windshear icon.
Aural warning: Nil.
Pilot Action: As Caution.
INDICATIONS ON THE ND:
The predicted windshear area is indicated by a red and black icon and two yellow radial lines.
Windshear information is available in ARC and ROSE ND modes.
When the ND range is set above 10 NM, a W/S SET RNG 10 NM message appears, requesting
the crew to adjust the ND range. It is displayed even if the weather radar is switched off,
provided the WINDSHEAR switch on the weather radar panel is set to AUTO.
Last edited by PT6A; 25th Feb 2013 at 01:26.