A320 Flaps / Slats locked (yes again !)

[sonicbum]

Gents thank you all very much for your inputs. I share the same thoughts myself but wanted to see if there were some more considerations that could have been made and gather some extra knowledge and there are definitely some very interesting points that came up.

Happy new year !

[pineteam]

Hello guys,

Could someone please tell me why on this table for the go around procedure in case of slats or flaps jammed on the right Colum there is a note saying '' Not allowed" only in case of F>3 and S=0 or S= 0<S<1 ? I'm pretty sure I learned that during my initial training but I can't figure it out anymore... That table is so not intuitive...
Edit: Plus also I don't really see the point of that table. For a go around, I can just rely on the VMAX displayed on the PFD right? It can only be more conservative. I understand if you intend to divert then it’s useful...

Thank you.

[vilas]

Originally Posted by pineteam

Hello guys,

Could someone please tell me why on this table for the go around procedure in case of slats or flaps jammed on the right Colum there is a note saying '' Not allowed" only in case of F>3 and S=0 or S= 0<S<1 ? I'm pretty sure I learned that during my initial training but I can't figure it out anymore... That table is so not intuitive...
Edit: Plus also I don't really see the point of that table. For a go around, I can just rely on the VMAX displayed on the PFD right? It can only be more conservative. I understand if you intend to divert then its useful...

Thank you.

It's true the procedure is a bit confusing. First the easier part to answer, for Max speed you cannot rely on displayed Vmax, actually VFE is displayed, because it comes from lever position while the limitation is due to most extended surface. Since you're always landing in Conf3 the displayed VFE will be 185kts which is not always the case. That is why the table gives you different Vmax for different combinations. For slat 0 and slat equal or less than 1 it says flap>3 not allowed because you cannot be selecting flap full with slat stuck at 1 or less.

[pineteam]

Hello Vilas,

Thank you! I mistakenly thought we were still using config full regardless. It makes sense now!

[vilas]

Pineteam
You may not refer to the Max speed table. Max speed is the real(not displayed) VFE of the most extended surface at Conf3 which can be seen on the indicator itself.

[Citation2]

• In case of go around , while retracting one step up , you get slats / flaps locked. Would you pull the speed instantaneously ? Or let it managed and then pull the speed during acceleration.

pilots are trained to pull the speed but if that occured during go around , pulling the speed will cancel SRS and revert to OP CLMB.

[pineteam]

Originally Posted by vilas

Pineteam
You may not refer to the Max speed table. Max speed is the real(not displayed) VFE of the most extended surface at Conf3 which can be seen on the indicator itself.

Thanks. the Max speed displayed on the PFD is ok to use as it’s more conservative than the ones on the tables. Got it!

Originally Posted by Citation2

• In case of go around , while retracting one step up , you get slats / flaps locked. Would you pull the speed instantaneously ? Or let it managed and then pull the speed during acceleration.

pilots are trained to pull the speed but if that occured during go around , pulling the speed will cancel SRS and revert to OP CLMB.

I will still pull speed. In a go around, Managed Climb is not available anyway. You always get OP CLB after SRS in Go around phase.

[fpuentegomez]

Originally Posted by Citation2

• In case of go around , while retracting one step up , you get slats / flaps locked. Would you pull the speed instantaneously ? Or let it managed and then pull the speed during acceleration.

pilots are trained to pull the speed but if that occured during go around , pulling the speed will cancel SRS and revert to OP CLMB.

If you are accelerating you are no longer in SRS, hence you should pull SPD to prevent an overspeed.

[sonicbum]

Originally Posted by Citation2

• In case of go around , while retracting one step up , you get slats / flaps locked. Would you pull the speed instantaneously ? Or let it managed and then pull the speed during acceleration.

pilots are trained to pull the speed but if that occured during go around , pulling the speed will cancel SRS and revert to OP CLMB.

Very good point for a discussion. Let's see pros and cons.

- "Go Around - Flaps"
- "Flaps 3 (or 2)"

BING !

Threats = surprise and startle to be added to what caused the go around (unstable ? no visual contact at DA/MDA ? etc..). The greatest priority (as always) is to fly the plane as getting distracted by the ECAM in this "critical" stage will most likely induce a mismanaged go around, especially if it hand flown (we have discussed elsewhere all the problems related to somatogravic illusion and startle regarding the Fly Dubai event), regardless of the fact of being above or below 400 ft AGL.
So the Go around sequence SRS/FMA - Positive Climb - Gear Up must be adhered to no matter what.

Once this is done we have 2 options (provided we are still below the GA accel altitude : Pull speed or let the SRS work.

What do we know : SRS maintains the current speed at Go-Around engagement or VAPP if higher (max VLS+25 kt with all engines working).(KNO) It also gives us several protections, especially if we went around for an actual or suspected windshear.(SAW)
We mush remember though to pull speed before the Accel Alt.(APK)

Second option : pull speed. It complies fully with FCTM guidelines of Slats/Flaps locked and anticipates the threat of a slat/flaps overspeed but we lose the SRS benefits.(APK) (KNO)

Both paths involves several if not all pilot core competencies and both paths can lead to a successful outcome with enhanced safety. The beauty of competency based training rests within those different approaches that can lead to a positive outcome.

[dream747]

Originally Posted by Citation2

• In case of go around , while retracting one step up , you get slats / flaps locked. Would you pull the speed instantaneously ? Or let it managed and then pull the speed during acceleration.

pilots are trained to pull the speed but if that occured during go around , pulling the speed will cancel SRS and revert to OP CLMB.

According to FCOM, pulling the speed does not disengage SRS.

Can anyone confirm after having flown the approach in selected speed, on the go around it will revert to managed speed, and the target speed will be limited to VLS + 25 (with VLS speed taking the actual slat/flap position into consideration)?

[vilas]

Pineteam I did not say use indicated VFE but by indicator I meant SFI, the Slat Flap Indicator which will show you position of the jammed surface and help you calculate correct Vmax. Displayed VFE is not always conservative. The present case when you retract from say Flap full to 3 displayed VFE will move to 185kt while the correct VFE is 177kts. So can cause exceedance. So look at SFI not VFE.
dream747 SRS is managed speed mode at ACC ALT it will change to OP CLB. If you go around with selected speed it will change to managed speed in SRS. Design philosophy.
Pulling speed in not a ritual. It's purpose is to stop acceleration to prevent VFE exceedance. If you are in SRS aircraft is not accelerating no need to pull speed. Meanwhile may be put AP on.Wait for acceleration altitude and SRS to Change to OP CLB only then pull speed to stop acceleration and deal with ECAM.

[pineteam]

Originally Posted by vilas

Pineteam I did not say use indicated VFE but by indicator I meant SFI the slat flap indicator which will show you position of the jam and help you calculate correct Vmax.
.

Sorry! Missread you! Undestood now! Much easier than trying to figure out that table! Thanks

[vilas]

Originally Posted by dream747

According to FCOM, pulling the speed does not disengage SRS.

Can anyone confirm after having flown the approach in selected speed, on the go around it will revert to managed speed, and the target speed will be limited to VLS + 25 (with VLS speed taking the actual slat/flap position into consideration)?

The SRS mode disengages:‐Automatically, at the Go-around acceleration altitude (GA ACC ALT), or if ALT* mode engages (above 400 ft RA)
‐If the flight crew engages another vertical mode
‐If the flight crew selects a speed while in SRS mode: SRS reverts to OP CLB mode and a triple-click aural warning is heard.
​​​​​​
To use a selected speed/Mach target, the flight crew uses the knob on the FCU to set the target speed, Selected speed has priority over managed speed. The only automatic change-over from selected to managed speed target may occur at go-around mode engagement.

[dream747]

Originally Posted by vilas

The SRS mode disengages:‐Automatically, at the Go-around acceleration altitude (GA ACC ALT), or if ALT* mode engages (above 400 ft RA)
‐If the flight crew engages another vertical mode
‐If the flight crew selects a speed while in SRS mode: SRS reverts to OP CLB mode and a triple-click aural warning is heard.
​​​​​​
To use a selected speed/Mach target, the flight crew uses the knob on the FCU to set the target speed, Selected speed has priority over managed speed. The only automatic change-over from selected to managed speed target may occur at go-around mode engagement.

Thank you Vilas.

Edit: I should have read my FCOM more deliberately!

[vilas]

What we discussed was actually straight forward. But incidentally we discussed go around. Now if you go around from flaps full the lever will be in position three and suppose flaps get locked between full and three. Can someone explain will you land in flaps lever at full or leave it at three?

[dream747]

According to the Flaps locked Abnormal Procedures, it says to keep CONF FULL if flaps are locked at more than 3. I’m not sure if the keyword is here is “keep”, but now that the lever is already at 3 is there any downsides if we shift the flap lever back to FULL?

If we keep the lever at 3, the max speed works out to 177kt, if we put the lever back to FULL, the max speed also works out to be 177kt. Both cases will require the GPWS LDG FLAP 3 to be on.

[vilas]

Originally Posted by dream747

According to the Flaps locked Abnormal Procedures, it says to keep CONF FULL if flaps are locked at more than 3. I’m not sure if the keyword is here is “keep”, but now that the lever is already at 3 is there any downsides if we shift the flap lever back to FULL?

If we keep the lever at 3, the max speed works out to 177kt, if we put the lever back to FULL, the max speed also works out to be 177kt. Both cases will require the GPWS LDG FLAP 3 to be on.

Thanks! I knew you have to land in Flaps full but I had missed the FCOM reference in the Flaps locked procedure. If flaps are Stuck beyond 3 then you have to land with lever in full due to gain control in Flap3 makes handling very sensitive.

[dream747]

Out of curiosity, what determines the difference in the gain control between CONF 3 and FULL? Is it the actual flap/slat position or it is the flap handle position?

Great discussion, as always!

[vilas]

Originally Posted by dream747

Out of curiosity, what determines the difference in the gain control between CONF 3 and FULL? Is it the actual flap/slat position or it is the flap handle position?

Great discussion, as always!

The reason is obvious, the handle position. Because the flap is stuck beyond 3 or may be at full but the handle needs to be brought back to full.
747 ignore this post it's incorrect, just check #41.

[pineteam]

Originally Posted by vilas

. If flaps are Stuck beyond 3 then you have to land with lever in full due to gain control in Flap3 makes handling very sensitive.

Hi Vilas,
Care to explain please?
Why with the lever position between flaps 3 and Full will change the gain control if the flaps or slats are stuck?
Thanks.