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Carpe D.M.
12th Nov 2009, 07:18
If one looks to the "Slats/ Flaps Jammed checklist" in the A320 QRH there is a matrix. This matrix is used to establish what configuration of Flap/ Slat you have and the applicable max speed for your config.
Example: In the simulator today I had Flaps at 3 and Slats at 0 configuration ( Slats jammed/ WTB on ). Max speed 177 knots.

Within that matrix there is reference to Slats > 3.

So here is my question/ confusion....The slats only go to 3. There is only 3 positions. Those been 18, 22 and 27 degrees. There is no greater than 3.

Any enlightenment please. Thanks so much.

Server too busy
12th Nov 2009, 08:22
Carpe, if you have a look at the box before that it shows flaps less than or equal to 3. In your case that would be the one to use. This would be 185kts.

Right Way Up
12th Nov 2009, 08:56
The number relates to the slat position that you get according to flap lever position. Which is not very intuitive I am afraid.


I am pretty sure the old QRH had only four boxes down the side whch you could directly equate to each dot.


The way I look at it is :

S=0 slat position at 0 dot.

0<S<1 slat posn greater than 0 dot but less than 1st dot

S=1 slat posn at 1st dot.

1<S<=3 slat posn greater than 1st dot but less than or equal 2nd dot. This is because slat positin does not change from flap 2 to flap 3.

S>3 slat posn greater than 2nd dot.

Meikleour
12th Nov 2009, 10:19
Carpe,
The way to look at this is to consider the Slat position RELATIVE to the flap lever selected position. As another poster pointed out, SLAT2 (as I call it) is the position for both FLAP2 and FLAP3. With the selection of FLAP FULL then you also get SLAT3 ( follow so far?) Thus as far as the table is concerned it may be possible to achieve an aircraft configuration which has Max Slat position + 0 Flap position - hence the relevant speed limit. Very Gallic and not very intuitive!! Hope you enjoy the course.

Microburst2002
12th Nov 2009, 12:23
Hi Carpe

This is a very interesting subject. Just one question: as I interpret FCOM 3.02.27 pages 2 and 3, the ECAM will display a MAX SPEED..... XXX line with the corresponding limitation. I mean, I think the table is there just for info, when you are at home studiying :8. If the slats lock occurs in flight we just have to follow the ECAM "action". Am I right? or in your sim you had to find out the limit in the table?*

As for how the table is the way it is:

Each slat angle has its own limit.

For slats 1 (18º) the limit is 230 kt.
For slats 2 and 3 (22º) the limit is 200 kt
For slats Full (27º) the limit is 177 kt

Any slat angle below or equal to 18º (position 1) has the same limit (230 kt) even for just 1º.
Any slat angle above 18º and below or equal to 22º (positions 2 and 3) has the same limit (200 kt).
Any slat angle above 22º, till 27º, has the same limit (177 kt).

The slats will lock only if they should move after a flap lever selection.

Therefore you will never have a slats lock after selecting flaps 3 in final approach (nor selecting flaps 2 from flaps 3 after a Go Around).
During approach, you can have it after selecting flaps 1, 2 or full, only.

If the slats move and then lock after selecting a flap position during approach you have the slat limitation for the intended position (230 kt if you selected 1, 200 kt if you selected 2, 177 kt if you selected full).

When slats lock after take off, you have the slat limitation of the previous flap lever position. During initial climb out with Conf 3 you select flaps 1 at acceleration altitude. The slats can lock at any position between 22º and 18º. The limiting one is 22º. Same when taking off with Conf 2. If you take off with conf 1, slat limit would be 230 kt.

So I guess the conclusion is that the limit is the most limiting of the two lever positions involved, previous when cleaning, intended during approach.

The same applies for the flaps positions, only the limits are different so you need to know with is the limit applying in each case, slats or flaps limit. Hence the table.

* Now I see that the table is needed for knowing what is the VFE next, so the procedure can be carried out. The ECAM does not display it, unfortunately.

TyroPicard
13th Nov 2009, 20:28
Good stuff, MB2002 except for
* Now I see that the table is needed for knowing what is the VFE next, so the procedure can be carried out. The ECAM does not display it, unfortunately.VFE next is always displayed on the PFD IAS scale! The table is there so you can plan the max speed on a go-around based on the landing config, and the retraction speed if diverting after the G/A. So you enter the table with your planned landing config.
The Slat column refers to lever position and the equivalent slat position.
S >3 is there to allow for a Slats lock on a go-around in CONF FULL - remember that these procedures are written for every possible flight phase/ config, not just the one you find yourself in!

Microburst2002
14th Nov 2009, 07:19
Yes

I have been calculating all possibilities when having slats or flaps locked during approach and VFE next is the same as the one displayed in the PFD except in the case of a flaps lock when selecting 2, because from 2 to 3 neither flaps nor slats will move so the VFE next is the same as VFE (200 kt).

Unless wrong

TyroPicard
14th Nov 2009, 09:08
I think you are making it a bit complex..
As the QRH says "VFE and VFE next are displayed on the PFD according to the flap lever position" and that is what you use as your reference when configuring the a/c. ("If not displayed, use the placard speeds")

The table is used to extract the maximum speed to be used in a G/A, and I would always recommend inserting that max speed as a constraint at a suitable waypoint in the G/A section of F-PLAN as a reminder (because you are in SEL speed).
Your example is technically correct but practically complex - the really important bit is getting the Landing Distance Procedure correct, and you might have to run the QRH in quick time if it's not your day.. I prefer to keep it simple.

rudderrudderrat
14th Nov 2009, 09:16
Hi MB2002, I agree with your synopsis - but does the VMAX "barbers pole" move in harmony with the acheived flaps / slats sensed position?

TyroPicard
14th Nov 2009, 09:20
You must have learnt that on your type-rating course.. back to the books!

Right Way Up
14th Nov 2009, 09:24
VFE based on flap lever position.
Overspeed warning based on actual flap/slat position.

A good gotcha if you retract slats late on a heavyweight aircraft!

rudderrudderrat
14th Nov 2009, 09:42
Thanks RWU

TP - Why do you think MB2002 is making it practically complex? He has correctly anticipated a problem with the presentation of VFE on the GA, and the barbers pole will be a reminder.

TyroPicard
14th Nov 2009, 18:31
TP - Why do you think MB2002 is making it practically complex? He has correctly anticipated a problem with the presentation of VFE on the GA, and the barbers pole will be a reminder.Complex because you don't use the table for VFE next, you use the PFD. If the lever is in FLAP 3, VFE next refers to CONF FULL, not some figure you have extracted from a table. The table is only used for determining MAX SPD and from that the recommended speed to use for a circuit, or to clean up for a diversion, following a go-around. On a go-around VFE next is irrelevant.
Airbus write very precise FCOM and QRH, so precise that most pilots think they are probably too concise. But this procedure contains all the information you need, and if you follow it with the same precision with which it was written it will get you down safely.

aristoclis
14th Nov 2009, 21:38
Hi to all,

I have been trying to understand why this discussion is being made guys, but obviously I was unable. #1 post is measleading (wrong speed), so are most of the next posts.

Table nothing to do with VFEnext. VFEnext is on PFD (iaw lever) and plackards.
Table has to do with actual abnormal configuration seen on the EWD (still blue if in disagreement with lever or at transit). So good to know your max speed (in advance before configuring for example dual hyd failures) even if ECAM will tell you. Also essential for go around planning (circuit or diversion) since you can from your EWD anticipate your actual configuration after a go around.

Tend to agree with TP.

Regards.

Microburst2002
15th Nov 2009, 05:54
The original question was about the table.
Yes, maybe I am making it too complex. As I said this is a very interesting subject and I am glad we have this thread so I will learn about it.

Let me recap and correct me if I am wrong, please.

The QRH italics say that displayed VFE and VFE Next are those corresponding to the flap lever position, therefore not to the actual flaps/slats. During approach this is quite good beause both VFE and VFE Next in the PFD will coincide in most cases with actual ones (except VFE next in the case I mentioned above, if you agree). (And also except VFE in the same case, the flap jam occurring before slats 18º, in which case VFE would be 215 kt instead of the displayed 200 kt).

After carrying out the procedure by setting VFE next -5 kt and then moving the flaps lever one step untill reaching lever at CONF 3 the displayed VFE will be the actual VFE (except in those cases, where VFE will be 200 kt instead of the displayed 185 kt).

In case of a Go Around to remain in the circuit (or to divert when flaps jammed > 0) according to the paper procedure we will maintain configuration ("Go around" instead of "Go around, flaps") and select VFE-10 kt. The displayed VFE applies except in the mentioned case.

Should we clean for a diversion we will do it between VFE - 10kt and VFE. From Lever at CONF 3 to CONF 1 the displayed VFE applies (except in those cases). Then, from CONF 1 to 0 we have to calculate what the VFE will be, since the displayed one will not necessarily be the actual one. There are 2 cases for cleaning:
- flaps jammed at zero: VFE will be 230 kt instead of the displayed 215 kt. So when passing 220 kt select flaps 0.
- slats jammed: VFE will be 177, 200 or 215 depending on where the slats jammed. So when passing 167, 190 or 205 kt respectively select flaps 0.

Argh!
The more I look at it, the less simple the slats/flaps jammed seems to me.

aristoclis
15th Nov 2009, 07:17
Microburst, I am sorry but what exactly do mean by

both VFE and VFE Next will coincide in most cases

If I understand this, I might be able to read the rest of your post.

Edit: When reaching lever at final position Conf 3 the displayed VFE is as you stated 185kt. The actual max speed for your actual configuration could be according to failure: NO LIMITATION, 230kt, 215kt, 200kt, 177kt. So I really find it difficult to understand when you say "the displayed VFE is the actual (185kt) except when it is 200kt.

Microburst2002
15th Nov 2009, 09:44
Hi

I have already ammended my post, because what I wrote was not wat I meant.

Regarding the actual max speed. Yes, it could be any. But if you have either flaps or slats jam, then it happens that actual VFEs and VFE nexts coincide with displayed ones (except in the case I mentioned in another post: flap jam after selecting flaps 2 in approach). I came to this conclusion studiying the table for a while, so I could be wrong, of course.

If there is a jam in both slats and flaps, it's a different story.

aristoclis
15th Nov 2009, 10:39
Hi Microburst,

The possible cases are many and in some of them what you say is true. But to keep things as simple as possible don' t bother if displayed VFE or VFE next happens to be the right one according to actual configuration. ECAM actions and paper checklist step by step will make things easy. Table is really straightforward.

P.S. I am sure you already have noticed the last note in the QRH just before the table. Max speed (from table) might be higher than VFE (displayed on PFD). In that case you may follow VFE.

TyroPicard
15th Nov 2009, 18:26
aristoclis
P.S. I am sure you already have noticed the last note in the QRH just before the table. Max speed (from table) might be higher than VFE (displayed on PFD). In that case you may follow VFE.In my QRH that last note refers to VLS not VFE - VLS is displayed on PFD and always valid for the actual flap/slat conf. Do you have a different QRH?

I said you guys were making it complex... I cannot tell from your profiles if you are A320 rated. The QRH refers to the displayed VFE next for configuring. It is always safe, you won't break the aircraft, you do not need to work out an "actual" VFE next as defined by MB2002.
On a clean-up for diversion you already know the VMAX in the landing config, so you can accelerate, select Flap 1, check/work out your new VMAX, accelerate and select Flap 0 passing VMAX-10 .. all done in slow time using SEL SPD.
It is far more important to maintain SA than to bury your head in the table more than necessary.

aristoclis
15th Nov 2009, 20:05
QRH REV 43 PAGE 2.04 (REV38 SEQ002) last note:

NOTE: . In case of go around with CONF FULL selected, the L/G NOT
DOWN warning is triggered at landing gear retraction.
.In some cases, MAX SPEED - 10KT may be a few knots higher
than VFE. In this situation, pilots may follow the VFE.

P.S. You can guess three times if I am typerated.

TyroPicard
16th Nov 2009, 10:28
Thanks aristo, complete lack of precision on my part! I was looking in the wrong place.. must use a window big enough for a whole QRH page...
TP

Microburst2002
16th Nov 2009, 13:34
Hi guys

I hadn't read that paragraph or I had mistook it with the one TP mentions.

I thought we should fly at VMAX-10 kt regardless of displayed VFE. But what does that may means? We can choose? Why? Now thinking, if we fly within the displayed barber pole... Will the normal law high speed protection intervene? The Overspeed warning will occur at actual limit, QRH says, so I don't think so, but I don't know for sure.

The problem in this failure is that we want to fly as fast as possible (without exceeding flaps/slats limits) because we haven't got the lift benefits of correctly deployed flaps/slats and our manoeuvring speed is higher than displayed. Though VLS is correct and as long as we don't go below it there should be no problem it is important to know what the max speed is. Particularly if we are heavy.

The table is straightforward for me too Simple things may become more difficult in final approach depending on circumstances, but that is what we get paid for.

aristoclis
16th Nov 2009, 15:27
Now thinking, if we fly within the displayed barber pole... Will the normal law high speed protection intervene?


Well, Microburst, you are quite a pain... but a pleasant one which reminds me how far below the desired level I stand on systems knowledge. I really can't tell. I suppose it will intervene in the correct speed. But to avoid surprises, since normally overspeed protection starts at VFE+6kt I would stay below this speed.

Microburst2002
18th Nov 2009, 14:34
Hahaha!:}

Yes I am!

ReverseFlight
26th Oct 2011, 05:11
I've dug out this old thread to ask a question about slats/flaps jammed resulting from a dual hydraulics failure.

I understand that a dual HYD failure leads to a loss of AP. If that's the case, how does one "select" Vfe minus 5 kts for flaps extension (in particular G+B, G+Y) ? If the AP is off, turning and pulling the SPD knob would be futile. Have I missed something here ?

Can Mb2002 or anyone else help ? Thanks in advance.

Right Way Up
26th Oct 2011, 07:53
A/P may be unusable but maybe ATHR is?!

ReverseFlight
26th Oct 2011, 13:54
You must be correct, as A/THR is not on the SYS INOP list for dual HYD failure.

I guess all I have to do is to select the required speed and A/THR (in SPEED mode) will command a slow down to Vfe - 5kts. Thanks.

ReverseFlight
6th Nov 2011, 02:09
A postscript to my last post for those who are interested.

For G+Y HYD failure, A/THR is available and used.

For G+B HYD failure, A/THR is available but the QRH/FCOM3 directs it must be switched off for the approach. I understand this is to prevent handling problems due to loss of multiple flight control surfaces, in particular L ELEV and L+R AIL, both of which are controlled by G SYS and B SYS.