Windshear

Question 1

What controller weather warnings would prohibit you from taking off of descending bellow 1000ft for landing

Answer 1

When the words “microburst,” “microburst alert,” or “shears of 30 knots or greater” are being broadcast by a controller, takeoff initiation or descents below 1000 feet AGL for the affected runway are prohibited.

Question 2

What uncontrolled changes from normal steady-state flight conditions below 1000 feet AGL would indicate the possibility of windshear.?

Answer 2

• ±one dot displacement from the glideslope
• ±5° pitch attitude
• ±15 knots indicated airspeed • ±500 FPM vertical speed
• Anunusual throttle position for a significant period of time

Question 3

For Takeoff, what steps are necessary if there is the probability of windshear

Answer 3

1) [PF, PM] Use maximum takeoff thrust. MAX thrust is selected by: • Selecting N1 LIMIT page and deleting SEL (assumed temperature) (1L)
2) [PF, PM] Use longest suitable runway that avoids areas of suspected windshear.

3) [PF, PM] Use flaps 5 unless limited by obstacle clearance and/or climb gradient. This setting provides the best performance for countering windshear.
4) [PF, PM] Use flight director display.

5) [PF, PM] Use
auto-throttle

6) [PF, PM] Verify/set V-speeds. If required, manually enter V-speeds. If Sabre returned a reduced thrust solution, use the reduced thrust V-speeds to help minimize the gap between V1 and VR. United Performance Engineering has authorized the use of reduced thrust V-speeds as the aircraft will accelerate to those speeds earlier during the takeoff roll using maximum thrust.
7) [PF, PM] Use VR MAX for rotation speed. Use the ACARS Takeoff Data message VR MAX for the actual increased takeoff rotation speed. Sabre limits the VR MAX to the lesser of MTOG VR or actual takeoff gross weight VR+20 knots. Note: Max Thrust VR speed should not be reset to VR MAX. In addition to the standard V-speed callouts, whenever an increased rotation speed is used, an additional callout of “VR” is required to identify the VR for the actual weight (e.g., “V1, VR, rotate”).
8) [PF]Rotate to an initial climb attitude to maintain the increased VR until above the windshear threat. Then decrease pitch to attain normal speed.

Question 4

On the ground or in-flight, what should be your actions if you hear the aircraft say:
“Windshear, windshear, windshear.”

Answer 4

GPWS(reactive) Windshear Warning

-Reject takeoff
Or, if landing,
Perform windshear escape maneuver.