Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Go-around A320 Slats /Flaps Jammed

Tech Log The very best in practical technical discussion on the web

Go-around A320 Slats /Flaps Jammed

Old 31st Jul 2020, 04:59
  #1 (permalink)  
Thread Starter
 
Join Date: Jul 2020
Location: India
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Go-around A320 Slats /Flaps Jammed

In 320 slats/flaps checklist for go-around it says

1)if slats fault for circuit mantain the config.recommended speed :Max speed -10 knots and for diversion SELECT CLEAN CONFIG.How do we select clean config if our slats are suppose stuck at 3?
2)if flaps fault for diversion its says if flaps jammed >0 recommended speed:Max speed-10.
why is there a difference in procedure of slats and flaps?
Learningtofly85 is offline  
Old 1st Aug 2020, 11:02
  #2 (permalink)  
 
Join Date: Nov 1999
Location: UK
Posts: 2,449
Received 73 Likes on 40 Posts
1) Airbus are asking you to move the flaps lever to config zero. The flaps lever position signals flight phase changes to the aircraft systems, and you can still move the lever even though the actual physical slats/flap surfaces might be jammed. For example, with flaps lever set at config 1 or above; go-around mode is available.

2) Can you be more specific with your question?
Uplinker is offline  
Old 1st Aug 2020, 12:05
  #3 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,393
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Uplinker
1) Airbus are asking you to move the flaps lever to config zero. The flaps lever position signals flight phase changes to the aircraft systems, and you can still move the lever even though the actual physical slats/flap surfaces might be jammed. For example, with flaps lever set at config 1 or above; go-around mode is available.

2) Can you be more specific with your question?
It is not only movement of the lever. If Slats are jammed when you move the lever to zero you also retract the flaps to zero. But when flaps are jammed it forbids you from doing the same i.e. from moving the lever to zero thereby preventing you from retracting slats. He asking why the difference?

Last edited by vilas; 1st Aug 2020 at 12:28.
vilas is online now  
Old 1st Aug 2020, 15:26
  #4 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,395
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Learningtofly85
In 320 slats/flaps checklist for go-around it says

1)if slats fault for circuit mantain the config.recommended speed :Max speed -10 knots and for diversion SELECT CLEAN CONFIG.How do we select clean config if our slats are suppose stuck at 3?
2)if flaps fault for diversion its says if flaps jammed >0 recommended speed:Max speed-10.
why is there a difference in procedure of slats and flaps?
Flaps only extended without slats reduce the aircraft stalling AOA and will trigger the protections earlier in normal law or leading You to approach to stall earlier in alternate law ; the aircraft manoeuvring characteristics are degraded, requiring extra care.
sonicbum is offline  
Old 1st Aug 2020, 18:20
  #5 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,393
Likes: 0
Received 0 Likes on 0 Posts
The procedure is poorly written. For diversion with slat fault it only says Select clean configuration. It naturally creates a question mark how to do it when slat is jammed. Then if you could do it because it's jammed at zero then why speed restriction of MaX speed-10? In case of Flaps fault it gives two cases, one jammed at zero where you retract slat to zero and then use normal speed and second jammed at >0 where speed is restricted to MAX-10. Obviously the Slat fault is to be taken as Slat jammed>0.
vilas is online now  
Old 2nd Aug 2020, 10:48
  #6 (permalink)  
Thread Starter
 
Join Date: Jul 2020
Location: India
Posts: 9
Likes: 0
Received 0 Likes on 0 Posts
Thank you for your replies.It clears the comfusion
Learningtofly85 is offline  
Old 5th Aug 2020, 11:10
  #7 (permalink)  
 
Join Date: Aug 2007
Location: Middle East
Posts: 92
Likes: 0
Received 0 Likes on 0 Posts
Hello everyone....
the only reason behind this procedure is DRAG....
Diverting with flaps stuck down causes a lot of drag and fuel burn compared with diversion with slats out & flaps retracted....
Rocket3837 is offline  
Old 5th Aug 2020, 11:26
  #8 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,393
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Rocket3837
Hello everyone....
the only reason behind this procedure is DRAG....
Diverting with flaps stuck down causes a lot of drag and fuel burn compared with diversion with slats out & flaps retracted....
There is difference in procedure for flaps jammed =0 and flaps jammed>0 while it is silent on slat>0 why is that?
vilas is online now  
Old 1st Oct 2023, 17:59
  #9 (permalink)  
 
Join Date: Dec 2008
Location: Birmingham
Age: 39
Posts: 175
Likes: 0
Received 0 Likes on 0 Posts
Lightbulb

Sorry, don’t understand that:

Scenario: you have flaps stuck near 0 and slats normal. You fly the approach with a VAPP of lets say 165kt. You go around. It says max speed -10 and maintain config. So the max speed would be in the red band and something around 190kts. So we accelerate after the go around into the red band to fly a circuit? Correct?

And the other question: slats stuck , procedure done, approach and go around plus diversion. Select clean config. Ok flaps are zero and the slats still out. Max speed will be something with 190kt. The NEW max speed is the speed for the current configuration?So we divert with that speed?

Thanks guys
Speedwinner is offline  
Old 1st Oct 2023, 18:38
  #10 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,297
Received 3 Likes on 3 Posts
The first sounds alright to me, except one thing.

Vls 60t ~ 135 kt. For Flaps stuck at 0,5 (less than 1 but not fully retracted) and completely operational slats, deltaVapp(failure) is +25 kt and flap-lever position "3".

Vapp = 135+25 = 160 (no further additives because of the large already increment), as you extend the LE devices according to procedure, the Slats will end up at 22 (middle extended dot) called "position 3"
ref: FCOM DSC-27-30-20 "A".

Your MAX SPD per the QRH table is 200 kts. For circuit, the procedure says not to change the configuration and fly @ -10 kt = 190 kt. That would be inside the red, because for "position 3" normally associated with slats = middle dot, flaps = 3rd dot, the barber pole indicates (according to lever position) 185 kt Vfe.

FlightDetent is offline  
Old 1st Oct 2023, 18:43
  #11 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,297
Received 3 Likes on 3 Posts
The other question, while rarely rehearsed, I agree the MAX SPD is dynamic.

Assuming Slats stuck just little extended (<1)
the landing conf is S=0,25/F=3 ..... max spd 185
> > > retract one step above max spd -10kt and get S=0,25/F=2 ..... max spd 200
> > > retract one step above max spd -10kt and get S=0,25/F=1 ..... max spd 215
> > > retract one step above max spd -10kt and get S=0,25/F=0 a.k.a. "select clean configuration" = with flap lever at "0" ..... max spd 230

and fly the diversion at 230 -10 kt.
FlightDetent is offline  
Old 2nd Oct 2023, 09:04
  #12 (permalink)  
 
Join Date: Apr 2011
Location: Europe
Age: 43
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by FlightDetent
The first sounds alright to me, except one thing.

Vls 60t ~ 135 kt. For Flaps stuck at 0,5 (less than 1 but not fully retracted) and completely operational slats, deltaVapp(failure) is +25 kt and flap-lever position "3".

Vapp = 135+25 = 160 (no further additives because of the large already increment), as you extend the LE devices according to procedure, the Slats will end up at 22 (middle extended dot) called "position 3"
ref: FCOM DSC-27-30-20 "A".

Your MAX SPD per the QRH table is 200 kts. For circuit, the procedure says not to change the configuration and fly @ -10 kt = 190 kt. That would be inside the red, because for "position 3" normally associated with slats = middle dot, flaps = 3rd dot, the barber pole indicates (according to lever position) 185 kt Vfe.
That might have to do with this?

Brotti is offline  
Old 2nd Oct 2023, 15:22
  #13 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,395
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by vilas
There is difference in procedure for flaps jammed =0 and flaps jammed>0 while it is silent on slat>0 why is that?
From an aerodynamics point of view a swept wing airplane like the A320 will have negative effects from flying with flaps extended and no slats out, hence the procedure (in case of FLAPS jammed) asking to maintain the landing configuration in even in case of diversion and to select clean only if the FLAPS are jammed exactly at 0, so no negative effects in aerodynamics.
If SLATS are jammed regardless of their position we can safely clean up the FLAPS as the airplane will have no adverse aerodynamics issues even with SLATS psn 3 and FLAPS 0. The opposite is not true, this is why when talking about Slats/Flaps locked we have only one condition which will lead the airplane in ALTN LAW, that is less than 17deg of Slats (less than Flaps position 1) and more than 13deg of FLAPS (At or above CONF2, but it would be more correct to say above Flaps position 1 imho).
In the above scenario the airplane is unable to retain Normal law due to the likelihood to hit easily alpha prot given the reduced stalling AOA and ALTN LAW intervenes without reduced protections to avoid UAS induced by the protections.
sonicbum is offline  
Old 3rd Oct 2023, 15:17
  #14 (permalink)  
 
Join Date: Dec 2008
Location: Birmingham
Age: 39
Posts: 175
Likes: 0
Received 0 Likes on 0 Posts
Thanks folks,

so basically, if i stay i keep the setup and the max speed minus 10. When i divert out of the go around i do change the config setting when initiating the go around right? So goaround-flaps?
Speedwinner is offline  
Old 4th Oct 2023, 08:50
  #15 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Posts: 2,395
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Speedwinner
Thanks folks,

so basically, if i stay i keep the setup and the max speed minus 10. When i divert out of the go around i do change the config setting when initiating the go around right? So goaround-flaps?
Yes. Basically if you end up going around and have already briefed a second attempt you will keep the config for any type of flaps/slats jam.
If You have briefed that in case of go around you would start a diversion then it is according to the type of jam you have as discussed above. If you can clean up, then it will be a normal go around profile with GA/Flaps.
One of the main points to remember of this failure is that you don't want to fly with Flaps extended and no Slats.

Generally speaking Slats/Flaps failure are often practiced in the SIM during takeoff when you do have plenty of fuel and no time pressure at all; actually quite the opposite as burning fuel and decreasing your weight is quite beneficial in that scenario.
Issues start if jams occur during final approach at or just slightly above minimum diversion fuel; that's where an adequate workload management will be essential to get out of troubles, especially if the destination is a short runway.
sonicbum is offline  
Old 4th Oct 2023, 12:21
  #16 (permalink)  

Only half a speed-brake
 
Join Date: Apr 2003
Location: Commuting not home
Age: 46
Posts: 4,297
Received 3 Likes on 3 Posts
Originally Posted by Speedwinner
So goaround-flaps?
Disagree.

Even if in your particular case there is no danger because moving the lever from 3 to 2 retains the same S position at 22 deg and nothing else moves,

nowhere does it say you should retract at the GA initiation. E.g. for go around (and circuit) you retain the approach conf, they say.

​​​​​It is only for the diversion where you are instructed to clean up >>>> by increasing speed manually to above_Vmax minus 10... and then retracting one notch at a time.
.. that reads to me as the acceleration segment, not the 1st or 2nd of a GA proc.

The normal G/A per SOP has its scope of use. Just because it is not spelled out explicitly does not mean it is perfectly universal.
​​

​​​
​​
FlightDetent is offline  
Old 4th Oct 2023, 14:24
  #17 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,393
Likes: 0
Received 0 Likes on 0 Posts
I posted it before that go around flaps is really applicable to flap full. It has performance issue. Flap3 to 2 or 2 to 1 is done for standardization. This was in Airbus discussion. Here when flaps are stuck between zero to two one step retraction doesn't move anything. Bu you can leave it till deciding to divert. Another issue is if you have to do another instrument approach then what? You do it with landing flap i.e.mostly 3 or retract to 2. Slat jam case it will move flap to 2. As for as diversion is concerned slat jam it asks you to retract flaps but in case of flap jam leave slat as they are. Slat/flap jam is critical during approach because with FPF 60%,80% and 180% for slat, flap, gear you aren't going anywhere. That's why only green fail looks innocuous but if weather is poor then putting gear down requires some consideration. Because you can't divert. In case of goaround would you hold for sometime for weather improvement or keep shooting approaches burning fuel needs some thought.
vilas is online now  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.