A320 multiple ECAMs selected in FlySmart landing performance app
 

Hi there, is anyone able to advise on the following please? FO 2,500 hrs, 1,200hrs A320.

On A320, with ECAM HYD G+Y SYS LO PR selected on the FlySmart+ landing performance app, Vapp is given as Vref + 25kt.

FCOM/PRO/ABN/FCTL/ FLAPS/SLATS FAULT LOCKED gives approach speed depending on slats/flaps position displayed on the upper ECAM display. With above hydraulics failure you would retain full use of slats but have no flaps, so Vref 25kt makes sense per the tables content.

However, if I add a second failure/ECAM to the landing performance calculation, e.g. F/CTL SLATS LOCKED - SLATS < 1 the Vapp is still given as Vref +25kts, where as I believe it should be higher Vref + 45kt according to FCOM table.

So two closely related questions if I may:

1. How does FlySmart+ deal with multiple ECAMs of this nature? From experimentation it seems to prioritise the dual HYD ECAM above F/CTL ones.
2. What's the best way to proceed if this were to be encountered? It seems to me there is an inherent threat present here because (reference above example) one could fly the approach at selected speed Vref +25kt when the actual slats position would dictate the higher speed Vref + 45kt is more appropriate.

Of course I may have missed something! Many thanks in advance for your time.

Probably one of the questions I want the answer to most, but nobody is chipping in :ugh:. I’ve been looking into the FCOM and can’t find if we should add the delta-Vrefs or just take it as the biggest; either one could be logical(the bigger Vrer will be able to cover the handling changes derived from both problems or you need to add Vrefs to really manage both sets of problems.

Regarding question number 2, have you considered, or asked someone in your training dept about, the failure condition of FLAPS/SLATS FAULT IN CONF 0 that appears on the FCOM? As that seems to me to be the most appropriate response to your scenario

I don't sit with the answer, but I could chime in with some thoughts. First, it's a bad day the at the office with G+Y HYD failure and SLATS LOCKED. Never heard about it happening but could possibly be the result of hitting something hard..? My major concern would be stopping distance, having only brake accumulator pressure and landing with a clean wing.

I personally think the whole ECAM checklist system works OK with simple, isolated, failures and I too have found scenarios where blindly following the ECAM would have you go down a path that only make things worse. (Both outer fuel transfer valve failures is one I can think of...). I know you were not asking about ECAM, but my point is you can't leave your brain at the door just because you go flying an Airbus.

I have not tried an FS calculation with the failures you mention but my gut feeling says Vref+45 sounds reasonable. (As a side not, I just happen to remember on the 737 it was Vref+40 for landing with flaps/slats up.) Before I decide what speed to fly, I would check it with the VLS and see if they match up some what. The body attitude is also of concern, as is flare authority with only B system available.

I think the way to mitigate this would be to select flap+slats locked at 0. Flysmart does not always cope well with multiple complex failures

The paper QRH in-flight performance section “Method to Determine Aircraft Performance at Landing with Several Failures” was a hideous mathematics quiz of a procedure but did handle this with no uncertainty.

It simply says “determine the VAPP using the highest delta Vref”. So in your example case FlySmart is in fact incorrect!

If you fly vref +25 with flaps and slats at zero you will be well below VLS. You should fly the highest delta VREF in this case which might not be enough. It’s + 50kt for no flaps no slats on A320; or just check where is your VLS and fly at least above it. The Flysmart is not designed for very unlikely multiple failures.

In the old times, when we used to do manual landing distance calculations with/without failures, on the with multiple failures section it stated to choose the highest resulting VAPP from the multiple failures we had, and that the max VAPP had a limit, can't remember the number.
Now, by punching all the failures in the EFB, it will answer back with the same assumptions we used with the paper calculations.

Flysmart and the “paper” documents will always give you the highest delta Vref from the combination of failures, that will ensure that control and performance margins are maintained.
They are not added.

You maybe mixing this up with Factored Landing Distance, this is where the landing distance with failures increments to are added.

To fly the scenario for a landing, use the QRH summary, start from the cruise, in the approach section do the flap selection per the FLAPS/SLATS FAULT LOCKED. A nice long final keeping the speed up help with control, gravity extension once going down the glide slope. Flare earlier.

My FCOM gives a Vref of +25kts for slats locked at <1. That’s still a flap 3 landing.

Flysmart doesn’t add the Vref for separate failures, it takes the worst and you use that.

The problem here is that they’re not separate failures in terms of performance. If you have slats and flaps at 0 you don’t take the worst of a slats OR a flaps failure, you have to combine them. Flysmart will consider combinations of slats/flaps failures and will give the correct delta Vref, eg +45 for slats<1 and flaps<1, but doesn’t apply the same logic to a G+Y LO PR and a slats failure.

This is identical to what the QRH does. It has performance for combined slats/flaps failures but does not have performance for other combinations. Presumably this is because the various flap/slat combinations are normally just different products of the one failure.

When the OP checks the QRH table for slats and flaps < 1 they are doing exactly what they should do in Flysmart. Put the complete wing surface position in as a separate failure, not just the slats, so that Flysmart can give the appropriate Vapp corrections and the appropriate performance penalties for stopping on the runway.

Sorry, re-read the OPs original point.
Flysmart leads you up the garden path a bit here, multiple failures like this are deemed so rare that Airbus considers it negative training.
However, if it were to happen, you would have to consider it a Flaps Slats locked scenario and act accordingly.