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-   -   Flaps/Slats locked. 320 question. (https://www.pprune.org/tech-log/482337-flaps-slats-locked-320-question.html)

WhySoTough 11th April 2012 09:22

Flaps/Slats locked. 320 question.
 
Hi,

Firstly I apologize for making another thread, but this is quiet a confusing failure for me still. I haven't been demonstrated it yet, but would like to fully understand it before I do get demonstrated.

If flaps fail to retract after TO, speed select, ask for ECAM actions.
You would definitely want to come back to land, correct?
Will configuring for landing mean flaps would NOT extend either, or it could be that they extend maybe, but just not retract?

Second scenario,

Flaps fail while you're in approach and have no time to calculate distance etc etc. go around if you weren't ready for this and retract flaps normally?
When doing an approach with flaps or slats locked, you will use conf 3, select Vfe next -5, and keep configuring.
Why exactly do we do this? Once activating approach phase, the speed decelerates below Vfe anyway..
Apply landing distance. Am I missing something else?

If BOTH slats and flaps locked after you select flaps 1, there is no need to select flaps 2, or anything at all now, correct? As it won't do anything..

I do apologize for the silly questions, but I'm a newbie just learning now.
Thank you in advance.

de facto 11th April 2012 11:01


Firstly I apologize for making another thread, but this is quiet a confusing failure for me still. I haven't been demonstrated it yet, but would like to fully understand it before I do get demonstrated.
Now this attitude will get you far in the right direction:ok:

I will try to answer your question in a general point of view as I am rated on B737 not Airbus.

If flaps fail to retract after TO, speed select, ask for ECAM actions.
You would definitely want to come back to land, correct?
Correct,if your flaps can not be retracted following your ecam actions,you would return to your take off airport.
Most probably some sensors in your flaps detected a malfunction during the retraction command.

Will configuring for landing mean flaps would NOT extend either, or it could be that they extend maybe, but just not retract?
Flaps are retracted using electrical commands to use hydraulic fluid to move torque tubes which in turn move the flaps in my aircraft,most probably the same for your airbus.
Depending of the failure the flaps may be locked for good or not.
If no assymetry,your aircraft most probably has an independant electrical motor to move those flaps down and up again.there may be limitation on your landing flaps (degree used) to reduce crew workload in case of a go around.your checklist will let you know.

Flaps fail while you're in approach and have no time to calculate distance etc etc. go around if you weren't ready for this and retract flaps normally?
Yes a very safe idea.But yor captain should have a basic idea of his landing distance based on different flaps setting and auto brake setting,and a common knowledge of the Qrh content of standard possible failures.
A flaps assymetry will not allow you to retract your flaps at all during the go around so you will have to limit your speed during go around as well as possible maneuvring issues.thrust available from both your engines should allow you to achieve most necessary climb gradients.

If BOTH slats and flaps locked after you select flaps 1, there is no need to select flaps 2, or anything at all now, correct? As it won't do anything..
it will most probably do nothing,however on 737,if assymetry occurs or sqew,the flap LEVER will be placed to the smallest detent to guide the crew in selecting the proper speed addition during the non normal checklist as the flaps will be locked at the failed position for the rest of the flight.

Always follow your trained procedures,never rush,always confirm your actions and at the end have a look at what was achieved to confirm your new aircraft status.
Then you will be able to continue the flight with a positive outcome.:ok:

BlackandBrown 11th April 2012 11:18


Correct,if your flaps can not be retracted following your ecam actions,you would return to your take off airport.
Hang on a moment, preparation is important for this on the Airbus. Handle it, discuss it, decide - and thats generic. Your landing performance maybe extremely limited especially if ou flaps are jammed at conf 1. We use DODAR. Beyond that consider a WOLF check for landing:

W- weight
O- operational factors at airfield: RFFL, weather, navaids, surrounding terrain etc.
L- landing dist available
F- Fuel (not such a factor for a return - possibly) - use the fuel penalty pages of QRH for divert too.

de facto 11th April 2012 11:33


Your landing performance maybe extremely limited especially if ou flaps are jammed at conf 1. We use DODAR. Beyond that consider a WOLF check for landing:
Yes of course, i had in mind the issue the problem of the flaps being able to be extended again not locked for good following a partial loss of hydraulics.On boeing 737 a flaps 15 would be made,for wich the landing distance increase is minimal.
However if they are locked for good,ie assymetryyes,after ecam you must consider your take off field weather,iperformance for the landing distance,auto brake setting versus runway lengh for brake cooling,is an alternate airport available,fuel/distance....
However if a decision to divert to another airport for a longer runway i would assume should be taken with a pinch of salt as there is no info available of your fuel burn with flaps extended.
A flaps up landing on my aircraft can be achieved with max braking in about 1500 meters,so with auto brake 3 around 3000 meters.

PENKO 11th April 2012 11:44

Okay, this is where PPRuNe starts to confuse people. Regarding the retracting of flaps, your QRH might say the following:

FOR GO AROUND IF SLATS FAULT:
 FOR CIRCUIT:
MAINTAIN SLATS/FLAPS CONFIGURATION Recommended speed: MAX SPEED -10 kt
 FOR DIVERSION
SELECT CLEAN CONFIGURATION
Recommended flaps retraction speed: between MAX SPEED -10 kt and MAX SPEED.
Recommended diversion speed: MAX SPEED -10 kt.
 IF FLAPS FAULT:  FOR CIRCUIT:
MAINTAIN SLATS/FLAPS CONFIGURATION Recommended speed: MAX SPEED -10 kt FOR DIVERSION:
 If FLAPS jammed at 0
SELECT CLEAN CONFIGURATION
Note: Recommended speed for slats retraction is between MAX SPEED -10 kt and MAX SPEED of actual slat/flap position.


So do not just start retracting flaps or slats, mind the speed limits!
Take it all one step at a time. Read your QRH.

de facto 11th April 2012 12:00


 If FLAPS jammed at 0
SELECT CLEAN CONFIGURATION
I think the question he asked if flaps were to be jammed to more than 0 after take off.
What does your QRH say?

Boeing systems allow flaps retraction/extention using an electical motor following loss of hydraulics.
The loss of hydraulics could be the failure that causes his flaps to remain down after take off.

However if the flaps are 'jammed',ie were locked into their position due to assymetry,no retraction or extension is possible in boeing aircraft.

PENKO 11th April 2012 12:12

It says it right there. Start reading from the top. flaps/slats fault: maintain config on go around if you stay in the circuit, otherwise retract following the caveats.

He flies Airbus 320's, so why mix in Boeing stuff?

Natstrackalpha 11th April 2012 19:56

Flaps and Slats / A320
 
I think de facto was only trying to help and with some good advice, there is no need to bite a chunk off just because he operates a B737, he sounds like a good Captain to me.

The SFCCs have one slat and one flap channel each. If the SFCC is caput, then the slats and flaps will extend or retract at half speed.
If one HYD inoperative, say, then the corresponding surfaces operate at half speed.
If you get an ECAM saying SLATS (F) LOCKED that will indicate that the WTB has caused the stoppage which is a mechanical failure.
If you get an ECAM saying SLATS (F) FAULT then this will mean you have got an SFCC failure which is a computer failure.
Any overspeed aural Warning and VLS will be for the actual flap/slat
configuration.
VFE and VFE Next correspond to the flap lever position.
If you are lucky enough to get a double SFCC failure then you have not got AP, FD or AT, nor have you got any characteristic speeds, which means no VLS so, simply use the QRH Op Data. As mentioned by de-facto (above) use Selected Speed.
then proceed with your initial ECAM actions. folow the ECAM.

When you then get your info (latest from the status) then you will be able to set the aircraft up for the landing (which is the whole point of following the status procedure) If you have a slat OR a flap failure, then you select Flap 3.
If you have slat and aflap failure, then flap lever to Flap 1 to enable G/A
mode, but you select FULL on the Perf Approach page.


If you have a Slats Fault then you are in Alternate Law which will change to Direct Law when you put the gear down. Do your ECAM actions then do the QRH, which, will give you your Appr speeds and and Landing Distance Corrections.

On theApproach Do the QRH drill: Landing with Slats orFlaps Jammed. But, to land without Slats and Flaps use the QRH Flight Pattern.
The PM will use the QRH to guide the PF through the approach. Selected Speed.

Use AP and AT if you`ve got them but A/P off by 500 feet and disconnect A/T by 500 feet if its a slat andflap failure. On finals you will find the the attitude is unusual so when you get visual don`t be tempted to change the pitch attitude but monitor the flight director. If you want to Go-Around then, for failures other than dual hydraulic, Gear Up, but maintain flap/slat configuration. For an SFCC double channel fault (Flap or Slat), remember that you will have no A/P, no FD and no A/T. Ok?

TyroPicard 12th April 2012 17:18

WsT
Hope these answers help - I have tried to write them as if we are in the briefing room before a sim session.....


If flaps fail to retract after TO, speed select, ask for ECAM actions.
You would definitely want to come back to land, correct?
Correct - but if your main engineering base was really close you could go there instead. There may be other factors such as LOVIS which would stop you returning to the departure airport.


Will configuring for landing mean flaps would NOT extend either, or it could be that they extend maybe, but just not retract?
If ECAM says FLAPS LOCKED (or SLATS LOCKED) then they will not move until the engineers fix them on the ground.


Second scenario,
Flaps fail while you're in approach and have no time to calculate distance etc etc. go around if you weren't ready for this and retract flaps normally?
Yes, go-around in selected speed at a safe speed for the CONF but do not move the FLAPS lever ... because the Flaps are locked. At a safe height perform ECAM actions, and eventually check landing distance and do approach preparation referring to STATUS and QRH.

When doing an approach with flaps or slats locked, you will use conf 3, select Vfe next -5, and keep configuring.
Why exactly do we do this?
CONF 3 because 1. the QRH says so... 2. CONF FULL might give control problems with abnormal config. We use VFE next -5 so that we are always flying at a safe speed for the abnormal Flap/Slat config.


Once activating approach phase, the speed decelerates below Vfe anyway..
NO ! We are in selected speed.......


If BOTH slats and flaps locked after you select flaps 1, there is no need to select flaps 2, or anything at all now, correct? As it won't do anything..
There is a specific ECAM for "SLATS and FLAPS FAULT in CONF ZERO" which instructs you to use FLAPS 1 lever position for landing - this means that G/A mode is available if you select TOGA.


I do apologize for the silly questions
There is no such thing as a silly question when you are trying to learn - keep on asking!

rudderrudderrat 12th April 2012 19:02

Hi TyroPicard,

NO ! We are in selected speed.......
I agree that we use selected speed to decelerate to VFE next-5.

However, once in the landing config, and with the appropriate VAPP inserted into the MCDU, why can't we use managed speed to take advantage of ground speed mini protection?

Natstrackalpha 12th April 2012 19:17


However, once in the landing config, and with the appropriate VAPP inserted into the MCDU, why can't we use managed speed to take advantage of ground speed mini protection?
You won`t have VLS though - if its a double SFCC failure.

As PENKO said

So do not just start retracting flaps or slats, mind the speed limits!
Take it all one step at a time. Read your QRH.

aristoclis 12th April 2012 19:27

"Why exactly do we do this? Once activating approach phase, the speed decelerates below Vfe anyway.."



Because once you have activated the approach phase in managed speed, speed target would drop to O, then S, then F etc. iaw flaps lever position. But these speeds most probably do not correspond to your actual configuration so you must disregard them (if present anyway). So selected speed VFE-5 will allow you to maintain a higher speed to fly safely and allows you to continue your configuration.

PS: VFE is also iaw to lever position, so in certain cases Vmax would be in the red sector.

@Rudderrudderrat: I guess anything "managed" could be unreliable due to inconsistency with the actual configuration. And yes vls and O,S,F consequently vapp are absent in certain failures.

WhySoTough 12th April 2012 21:14

Thank you ALL very much for the kind and helpful responses.
I definitely understand the concept now.
Silly me asking why we use Vfe next since approach phase is activated.
Obviously, we are using selected speed:}

Thank you all! :)

aristoclis 13th April 2012 09:23


However, once in the landing config, and with the appropriate VAPP inserted into the MCDU, why can't we use managed speed to take advantage of ground speed mini protection?
Hello Rudderrudderrat,

I 'll try to make a better approach to your question since I wondered about this myself.

DSC-22_30-90 P 10/14

GROUND SPEED MINI FUNCTION PRINCIPLE
...
The lowest speed target is limited to VAPP and its upper limit is VFE of next configuration in CONF 1, 2, 3 and VFE-5 in CONF FULL.
...
Vapp would be fine as a low limit but the upper limit (since VFE and VFEnext are iaw lever position) would be inconsistent. So you would have a partially functioning Ground Speed mini (in certain failure cases the upper limit would "touch" the max speed i.e. 177kt ).


320p 14th April 2012 06:40

hello,
On this topic,I have two question regarding situations in which Flaps/slats do not extend normally which could also be because of dual Hyd failures or for some other reason.
- Since it is recommended to fly with selected speeds,after the final flap lever selection do we continue approach with selected Vapp or should we manage it to use GS mini?
- If it is selected Vapp then what is the significance of feeding Vapp in the Mcdu?

Thanks.

kellykelpie 14th April 2012 08:06

I teach Flap 3 then manage speed - you are only in selected speed until final flap. Fly managed after that.

For landing slats and flaps at zero, I teach select Vref + 60, then at 500 feet manage speed (Vref + 50). Works a treat.

There is nothing in FCOM about not using managed speeds for landing.

Cough 14th April 2012 08:13

Don't forget, after double system failures, the approach is likely to be in alternate law, with the landing in direct law.

By using GsMini for the approach, you may make life slightly more difficult for yourself as your trimmed speed will be constantly changing...Just at the point that you have lost auto trim...

Anyhow, KK, check FCTM AO-027. Selected speed MUST be used...

rudderrudderrat 14th April 2012 08:52

Hi Cough,

By using GsMini for the approach, you may make life slightly more difficult for yourself as your trimmed speed will be constantly changing...Just at the point that you have lost auto trim...
Then it will handle just like a Boeing.
Without the use of ground speed min - the IAS will vary during the gusts, requiring you to change the power and chase the speed.

I agree you must select speed during reconfiguration because the system would be working to the wrong speed schedule. However, once in landing config and with the appropriate VAPP inserted, what's the technical reason I can't take advantage of GS mini protection by using managed speed?

NigelOnDraft 14th April 2012 10:08


However if a decision to divert to another airport for a longer runway i would assume should be taken with a pinch of salt as there is no info available of your fuel burn with flaps extended.
There is plenty of info :ugh: Fuel Burn from the gauges x Time = Fuel Used. Yes, FMC thing no use, but so what?

NoD

de facto 14th April 2012 10:17


There is plenty of info Fuel Burn from the gauges x Time = Fuel Used. Yes, FMC thing no use, but so what?
Ok read and go,and planning?i never said its not possible,its not a perfect solution.

Yes, FMC thing no use
Are you trying to reduce your english level for the masses to understand?:ugh:


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