PPRuNe Forums - A320 SRS During Windshear

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- - A320 SRS During Windshear (https://www.pprune.org/tech-log/579237-a320-srs-during-windshear.html)

Quote:

Originally Posted by vilas (Post 11187548)

sergie
The answer to your para1is in FCTMGENERAL GUIDELINES

Predictive windshear@ warning (“WINDSHEAR AHEAD" and "GO AROUND WINDSHEAR AHEAD" aural alerts, associated with the W/S AHEAD that appears on the PFDs), reactive windshear warning ("WINDSHEAR WINDSHEAR WINDSHEAR" aural alert, associated with the WINDSHEAR that appears on the PFDs) and windshear detected by the flight crew, request immediate actions.

The following recommendations apply for takeoff after V1 and when airbone (including approach and go around phases):
- The flight crew must set TOGA thrust and should follow SRS orders (if necessary pull the sidestick fully back).
  
  If the FD bars are not displayed, the flight crew should move toward an initial pitch attitude of 17.5 °. Then, if necessary, to prevent a loss in altitude, increase the pitch attitude.
- If the AP is engaged, the flight crew should keep it engaged. The AP disengages if the angle of attack value goes above αPROT
- The flight crew should monitor the flight path, the speed and the speed trend.
Suspected windshear (upon ATC or traffic notification or flight crew observation) and predictive windshear@ caution (“MONITOR RADAR DISPLAY" aural alert, associated with W/S AHEAD that appears on the PFDs) request anticipation of the flight crew to be prepared for a possible windshear

It's about actions just in case of....
So it seems that FLEX T/O is permitted in case of suspected w/s , and if suspect is confirmed by crew or alert - use TOGA ,otherwise use flex...
There is a list in FCTM that gives precautionary measures for appch with suspected w/s. I thought that there is something similar for T/O in manuals. Thanx.

Quote:

Originally Posted by sonicbum (Post 11187558)

Hi Sergei,

Are You referring to the fact that when the predictive windshear procedure migrated from the FCOM to the FCTM the wording and format changed?
In the "old" FCOM PRO-SUP-91 Adverse Weather the use of TOGA as a precaution was specifically mentioned. In the FCTM the use of TOGA is related to the crew and/or PWS detection of the windshear.
Is that what You were thinking about?

Cheers.

YES! Because I checked SUP for Adverse Wx especially W/s and found nothing :)
I just wanted to highlight the priorities of SRS. FCOM doesn't specify this.

Hi Sergei.a320 Would you be able to share with me the SB that covers the SRS logic. Cheers

Sorry you are wrong. As long as you are in TOGA, SRS will guide windshear escape. A/C will not accelerate until you set TL to CL detent. FMA will flash but thats only a reminder due to the THR RED ALT in MCDU. That has nothing to do with SRS. Climb modes only valid in CL detent. “Windshear” indication on PFD also only visible on PFD until 1300ft RA, then it goes away, even if still in WS. So you SRS will guide you if necessary all the way down to Alpha max speed, but out of 1300ft RA you will be guided V2 speeds until CL detent is selected.

Quote:

Originally Posted by trkairbus (Post 11765775)

Reference please.

Quote:

Originally Posted by trkairbus (Post 11765775)

Do you have a reference for “climb modes only valid in the climb detent”?. Because that is not what the aircraft does. The acceleration altitude is what drives the climb mode transition from MAN TOGA / FLEX to OP CLB / CLB. The throttle position is not part of it. For example today departed (aircraft, not simulator, new and well-updated software) with some turbulence and a very heavy airplane. Acceleration altitude came and OP CLB engaged, along with the LVR CLB indication. Still in MAN FLEX XX with A/THR blue. Waited until after pitching the nose down and establishing a positive acceleration trend, which took quite a while. Only at that point brought the thrust levers to CLB causing THR CLB and A/THR white to hit the FMA. Already in OP CLB prior to thrust lever movement.

SRS switching to OP CLB and giving the LVR CLB indication has absolutely nothing to do with thrust lever position. The opposite (OP CLB to SRS) is however fully dependent on you hitting the TOGA detent, even for just a brief moment.

Quote:

Originally Posted by hikoushi (Post 11766270)

SRS will change to CLB/OP CLB at ACC ALT even in wind shear. LVR CLB will only flash when aircraft reaches THR RED ALT. It has nothing to do with SRS. If LVR CLB is flashing and SRS has changed to CLB then it will provide protection from overspeed by pitching up unless ALT* engages then there's no protection.