Flaps/Slats down during turn-around

[SMT Member]

I've noticed a number of carriers, LX and OS to name two, not fully retracting flaps and slats during turn-arounds.

What are the benefits of this (I'm assuming less wear and tear on motors and bearings), and is it possible to quantify it? Furthermore, there is bound to be downsides to this procedure, and I'm equally interested in hearing what they may be.

[Capt Claret]

On the B717 it is not unusual to see flaps and/or slats droop during turn around, due essentially hydraulic pressure bleeding off with no power source.

The danger of them being down during ramp activity is that the clearance below the wing is reduced and the chances of damage increased.

[compressor stall]

In hot weather (over 30C) the Airbus FCOM recommends leaving them in config 1 to avoid spurious AIR L/R WING LEAK warnings.

[hetfield]

On A300 it's SOP with most companies to retract S/F to S15 only after ldg.

Reason: most T/O are done with slats only, so another retract/extend cycle can be avoided.

Hope it helps

[SMT Member]

Thanks CS, that would explain why I saw them down on a LX A340 and an OS A320 in Tel Aviv recently - temps were well above 30C.

[NVpilot]

Furthermore, there is bound to be downsides to this procedure, and I'm equally interested in hearing what they may be.It's great for getting the flaps damaged on our A321, of no benefit for anything else in my opinion.

[Antunes]

In the Airbus 320 family, as compressor stall said, you should keep the flaps at 1 to avoid "AIR L(R) WING LEAK" message on ECAM.

There is another scenario you shouldn't retract the flaps, and that is when the approach was made under icing conditions or, if the runway was contaminated with slush or snow.

In this case you should taxi with landing configuration (normally flaps full) to the gate, shut down the engines, and have the flaps/slats area inspected by ground personnel. If there is no ice obstructing the area, you may retract the slats/flaps normally.

Don't know if there is a specific procedure for Boeing aircraft though...

Antunes

[hikoushi]

On our typical 8-sector day (flying the lowly Dash-8:ok:), part of the After-Landing checklist is to set the flaps to the takeoff setting for the next departure (it is checked again on the subsequent After-Start). This serves to save unneeded cycles on the Flap Power Unit, and double-assures that the flaps will be set properly for the field length of the next takeoff, as we operate into a combination of short and longer runways on any given day. Ice is not a factor in our area of the world, and the high wing keeps the flaps out of the way of potential FOD.