A320 slats jammed why not land woth flaps full

[kruzzik]

The slats jammed procedure demands flaps 3 for LDG. What’s the reason? Why not benefit from flaps full? Thanks!

[enzino]

You may find your answer in the G+B dual hydraulic abormal procedure where it says to extend the landing gear at 200 knots to have better pitch authority in direct law with the remaining elevator and no slats.

Just a hunch.

[OPEN DES]

Flaps only increases lift but at the expense of slightly reduced stall angle of attack. Mostly flaps are there to bring the pitch down for app/ldg. Flaps 3 does that adequately and there is further little value in additonal flap

[Tail-take-off]

Originally Posted by enzino

You may find your answer in the G+B dual hydraulic abormal procedure where it says to extend the landing gear at 200 knots to have better pitch authority in direct law with the remaining elevator and no slats.

Just a hunch.

But with all hydraulics working and the slats jammed (WTB on) you’d still have both elevators.

It could be as simple as Airbus only flight tested it in config 3. Does it really matter? Do what the PRO-ABN says and leave the whys and wherefores to the test pilots.

[enzino]

Originally Posted by Tail-take-off

But with all hydraulics working and the slats jammed (WTB on) you’d still have both elevators.

True, but I was thinking about the downwash of the airflow caused by the flaps without being re-energised by the slats. Just an academic guess.

[West Coast]

What guidance does the QRH give, if at all, wrt final flap setting?

[Tail-take-off]

Originally Posted by West Coast

What guidance does the QRH give, if at all, wrt final flap setting?

The FCOM & ECAM says Flap 3. Not sure why anyone thinks that they know better than the manufacturer.

[FlightDetent]

Originally Posted by enzino

True, but I was thinking about the downwash of the airflow caused by the flaps without being re-energised by the slats. Just an academic guess.

Same fantasies here. Slats provide a lot of airflow on the deep end of the wing, or so I was told.

But there was an interesting point upthread, that Airbus may have not flown tested such and such ... got me thinking. There is abundance of F3 in the System Failure tables. So I gather the F3 is actually the good flap. And F4 only provided for a "deep" setting to comply with the Vat limit for 140 kts Category C aeroplane at MLW. Looking at the numbers, especially the non-HGW A321 and the A321NEO, that design goal is rather obvious.

Accepting the idea that loosely speaking F4 is the workaround flap, it would make a lot of sense to see this F3 being used whenever justifiable.

[vilas]

Originally Posted by FlightDetent

Same fantasies here. Slats provide a lot of airflow on the deep end of the wing, or so I was told.

But there was an interesting point upthread, that Airbus may have not flown tested such and such ... got me thinking. There is abundance of F3 in the System Failure tables. So I gather the F3 is actually the good flap. And F4 only provided for a "deep" setting to comply with the Vat limit for 140 kts Category C aeroplane at MLW. Looking at the numbers, especially the non-HGW A321 and the A321NEO, that design goal is rather obvious.

Accepting the idea that loosely speaking F4 is the workaround flap, it would make a lot of sense to see this F3 being used whenever justifiable.

Yes. I asked Airbus with G and Yallow fail flaps are jammed and slat has no 3 position then why land in lever flap3? The answer was for certification they submitted abnormal landings will be in Flap3.

[FlightDetent]

Thanks vilas!