A320 Status page Appr spd

[PilotJames]

Heya guys,

Just wondering if someone could confirm with a reference whether the status page on the A320 is dynamic.
When is says Appr spd: VREF +25
Is this dependant on current aircraft config. With some failures (flaps + slats locked) as you configure this speed shown may change depending on the current config?

[FlightDetent]

The speeds on FMGS are static. The computer will pull Vls for CF Full or 3 dependant on pilot selection from a table of weights, and apply wind corrections as per algorithm. The machine does not know the status of the aircraft. The procedure for calculating Vapp for failure cases is purely manual based on QRH tables.

[RUMBEAR]

VREF + 25 is independent of actual configuration anyway. VREF is relating to full only. The + 25 ( in this example ) is to make a speed allowance for configuration ( when different to full ) and/or to improve handling quality.

[vilas]

The machine does not know the status of the aircraft. The procedure for calculating Vapp for failure cases is purely manual based on QRH tables. The VLS is real time speed and is always correct for the present configuration. When there is slat or flap failure the Vapp is not known that time. That is where QRH given addition gives you the target Vapp but when you select Conf3 to land the VLS even with one surface jammed is correctly calculated and you land at that VLS.

[Lantirn]

Villas, do you know if the STS message about APPR SPD is always correct?

[FlightDetent]

By "the machine" in the part vilas quoted I ment FMS. Trying too hard to avoid the word "box" that I loathe. :E Sorry for any confusion caused.

Lantrin: No, it is not always correct. And the wording is slightly misleading too. But nitpicking aside, yes it may and should be used. (for single type failures when FWC correctly and in full reports what's gone wrong. Assuming one does not forget to properly work out a/thr and ice accretion additives)

[Lantirn]

FD thanks. Have you actualy seen this happening in multiple failures? (except dual FWC failure)

[FlightDetent]

Eh, no, but not my point.

1) the STS shows delta V(failure). To calculate Vapp you need to take into account A/THR additive, wind correction and ice accretion. So into the QRH anyhow.

2) Real problems sometimes come in pairs, i.e. you dispatch with 1 pair of spoilers locked closed per MEL and then something ...

3) It is actually fine, but only if the malfunction plays by the rules.

It was more of a general comment aimed at the word ALWAYS. I remeber OEB for dual bleed fault and dispatching with 1 side inop - and the paper procedure was clearly not designed for such configuration. So, whenever the clever systems come to show me something, I always approach with caution and proceed further only once having verified the problem (for which a solution is being presented) is the exact one I actually have. As a computer kid, I refuse to take them at face value. ;) One of my early SIM instructors used to say: "the travesty normally begins as people correctly execute a wrong NNC". That was 737 with a printed set in QRH, but FWC does not shield us completely from the very same trap.

[vilas]

The OP is vague. On STS page there is only speed additive. So what's the question? It helps you calculate Vapp for the failure.

[PilotJames]

Just to clarify, as I can see my question is a tad vague.
I have an Airbus PDP (Procedure data package which is an Airbus produced document) and it says for a slats fault or flaps locked (essentially where flaps or slats are locked in an unusual config for landing) then on he staus page it has an approach speed correction. I used +25 as an arbitrary figure.
It says the approach speed correction on the status page is dependent on current flap and slat position and is updated for landing?
I can't find that anywhere in the FCOM.
Cheers for the answers so far guys.

[vilas]

PilotJames
It says the approach speed correction on the status page is dependent on current flap and slat position and is updated for landing?
True. The slat/flap can jam in different combinations and the STS page gives you the appropriate Vref addition to allow you to calculate Vapp. It is not the STS page but the VLS that you see is gets updated as you configure. As I wrote before VLS is real time speed. Its displayed value is always correct whether in normal or abnormal situation with one surface jammed.

[LHRPony]

In the sim I had a g hyd loss + y overheat. It came up with vref + 25. (Which is worst case for slats only) As it was a stopping problem we agreed to turn on the y pump on base, and hopefully keep the pump for the brakes.
So we configured on downwind and got slats only as expected. (Flap 3)
We then turned on the y elec pump for the app. It worked for about a minute before it overheated again. In that time the flaps ran out.
On reviewing the status page the delta vref was now+ 10,(as we now had slats & flaps)
So if I understand your question yes the delta vref does update on the status page as things change, but no I can't give you a reference.

[vilas]

PilotJames
STS page is part of ECAM so it is always dynamic with failures. Let's say you have slats jam the STS page gives you Vref+25. This is a speed additive to Vref to know Vapp. When you start configuring by taking flap it will still show Vref+25 but while selecting flaps if you get a flaps jam the STS page will take a note of it and give you different additive may be Vref+60 or alternately if you recover some slat as Pony stated it will may give you Vref+10. It says the approach speed correction on the status page is dependent on current flap and slat position and is updated for landing? It means dependant on current flap/slat jam position not on configuration. It will only change if the jammed slat/flap position changes.

[PilotJames]

Thank you for your replies guys. That makes sense now. I think it's just confusing how it's written!