For example as mentioned here I wonder to what extent this is type dependent.
The TB20 POH does not authorise retracting flaps (from MAX) post-landing, and the big flaps must be doing a lot of aerodynamic braking, especially at the start of the landing roll when the airspeed is still high.
I’m not sure it’d help that much – most faster planes that could benefit have very slow moving electric flaps. Also there’s the risk of reaching over and grabbing the gear switch by mistake!
I used to do this, following what my instructor had told me way back. Then on my CPL checkride the examiner said, very nicely, “don’t EVER do that because one day you will retract the gear.” I haven’t done it since. In any case if you need to brake so aggressively that it would make a difference, you have already made a major error of judgement in deciding to land there in the first place.
alioth wrote:
Also there’s the risk of reaching over and grabbing the gear switch by mistake!
That’s why it’s not taught anymore. In my Comanche POH it is listed as an option to decrease landing roll distance. But obviously, mistakenly actuating the gear lever would decrease landing roll even more.
UdoR wrote:
would decrease landing roll even more
Is that not what you were after when using that procedure? )p
The TB20 is my first and only retractable plane that I’ve flown. In the POH it says that there is a pressure sensor on the gear, to prevent retracting the gear accidentally whilst on the ground. Is this not standard across all planes with retractable gears?
Also helpfully the older Beechcraft types had the flap and gear switches in the reverse position to convention.
And again a big + for non-retracts on SEP… one thing that one doesn’t forget to select either down or up, select to down or up by mistake, is complicated, is heavy, can fail in any position, and is only marginally better (if at all) dragwise… ok, can look sexy on certain aircraft… but I digress 
Retracting flaps on touchdown to maximise braking?
There quite a few aircraft, including mine, having mechanically actuated flaps. Retracting them after landing can also be done just to kill lift and ensure the ship stays put on the runway, the more so in strong crosswinds. Flaps are then retracted as the touchdown is made.
One technique used when taking off from very short strips (e.g. < 200m, you don’t know what you guys are missing 
) or bumpy ones, is to rapidly increase the power whilst releasing the brakes, push to raise the tail @ about 20kts, and at about 25 knots to extend the flaps to mid position, pull slightly and accelerate in ground effect to retract said flaps, then Vx and finally Vy… required ground distance < 100m. It all happens pretty quick.
FAA, safety leaflet, 1980s:
“All aircraft certified to operate in US Airspace MUST be able to taxi faster with flaps down than with undercarriage up.”
Maoraigh wrote:
FAA, safety leaflet, 1980s:
“All aircraft certified to operate in US Airspace MUST be able to taxi faster with flaps down than with undercarriage up.”
Pictures or it did not happen :-)
Seriously, that’s some wicked humor from the FAA, would love to see the source.
