Guru - using CB's as a switch is not recommended because CBs are not meant to be used as switches. Simply put, switchs are meant to make electrical contacts without arcs. CBs might not be "arc free"...

More on maximum flaps on landing roll - yes max flaps causes more drag than lift, but remember the speed/drag formula thingy, at low speed, the amount of drag caused is low.
Increase speed 2x, drag increases 4x, vice versa.
So for me retract the flaps if you need max braking.

Same principal with large aircraft having spoilers:
- Used in the air they are known as speed brakes.
- Used on ground they are known as lift dumpers, because their main purpose is to destroy the lift & get the weight on the wheels, although the spoilers do contribute to drag to slow down the aircraft, but probably only when the aircraft speed is still high (right after touch down)

sad
 

are you serious!

must be the most pointless post ever.

I was being ferried to a spraying outfit an hour or so away from base in a very ancient C172. Over our destination looking at the paddock containing our one way strip the pilot remarked to me there wasn't a whole lot of space to get it in. To reassure him I reminded him of the gentle uphill slope and the spray aircraft already on the ground. On short final with full flap his speed was about right but at the full-flare stage he reached down for the handle and literally dumped all flap. The aircraft sat on the ground in no uncertain terms and remained there; I don't remember how much braking he used. It was the first time I had seen such a thing done whilst still airborne and I have to say it worked on this occasion but I would need to be pursuaded to use the same technique myself. Does/has anyone else regularly dumped flap in the flare?

As I have said in my above post, it is perfectly safe if done at the correct height/speed. I have done it a number of times on 172s and others and been able to achieve the desired results without compromising safety.

The post above has reminded me that I too have dumped flap in an Arrow on downhill grass. Fading memory apparently.

A C172 flown at the correct airspeed will touch down with very little float and will stop in less distance then it is possible to take off in. If you need to retract the flaps in the flare to get the aircraft on the ground you are approaching too fast. The correct response is to go around. If flying instructors are teaching retracting flaps before the aircraft is firmly on the ground then they are IMO exibiting very poor airmanship.

Did it many times for fun to show short field distance on Pipers (mainly the "Archers" , with nosewheel) Was quite impressive , if done just before touchdown- mainly to show off and get the first intersection (which was actually meant to be a line up for departure one couldn't be normally used as an exit :-)
Don't do this at home, you need to be really experienced , no low-hour stuff, wouldn't do it now as I don't have too much recency in SEP anymore.

On tailwheel , like a C185 , it was usefull do dump lift and get the tailwheel firm on the ground after a wheellanding (especially in (strong) crosswinds).
same on Piper Super Cubs allthough less noticeable.

This is all true on planes with a flap-handle where you can raise your full flap in a blink of an eye.
Can't see the point in C172 types with electrically operated flaps as the flap travel is too slow to have an effect. (I vaguely remember a nosewheel four-seater cessna with a manual flap handle though , have to get the logbook out for that one)

Finally it was a placard in at least the Beech Sundowner , literally :
"Raise flaps to increase brake effectiveness".
I guess it was after reading this placard I started using it as mentioned above.
Basically flew thousands of hours on SEP without the need to use it !

In the PA28 that I used to teach on we could stop before the PAPI's..!

Touchdown on the stall - dump flap - full aft on the CC and Max braking.

15m or less every time. A real eye opener for the uninitiated as it was for me the first time it I sat through it..!

An easy drill to teach to the more proficient of students.

I kind of miss those days but not the pay :}

was taught it at Denham (EGLD)... along with the pros and cons (frowned upon by some) of retracting a stage of flap as a last resort on final approach on a PFL.... which I read with interest was utilised by the skipper of the BA B777 into Heathrow to make it over the airfield perimeter.



MG :ok:

Yeah, read that the BA 777 crew retracted flaps, that's why they managed to actually made it "safely" short of the runway.

BUT, as far as I can remember during my PPL training, you NEVER NEVER retract flaps after extending them while on final. You don't want to sink that close to the ground.

What the BA 777 crew did probably was not "per SOP" I think, but it worked. Retracting late stages of flaps reduced drag more than lift.

The USAir that ditched in the Hudson, the crew did something not "per SOP" too - I read that they switched on the APU even though it was not part of the engine out procedure, & that probably helped 'save' the aircraft.

But if you do something that is not part of the SOP & caused something bad to happen, you've had it...
You do everything as per SOP & still something went wrong, that's fine...

Good operating techniques are aircraft specific. There are lots of things that are good operating practices in light singles that would be an extremely bad idea in a heavy jet airliner, and vice versa..........

Anyone want to lend an arbitrary low-houred PPL their aircraft to try out some of these techniques?


Thought not. :suspect:

I was never taught it ever, anywhere! And I can't imagine it being good on the gear.

I saw it done by a pilot and thought he was just showing off... I'm surprised at how "commmon" it seems to be. I also noticed people doing it at competition in order to "hit" the first landing sections of runways to get the max. points. Because of a number of bad results (i.e. damaged gear) they then forbid it, which I think is a sensible idea.

As many have pointed out in Cessnas (at least the singles I flew) this is the procedure for a proper short field landing.

In many aircraft including turboprops and some Heavy Jets a go around requires raising the flaps one notch. The previously mentioned 777 crew would have been flying a safe speed for one notch less flaps which as you can tell worked out great for them. Less Drag = they made it further.

I have not seen the show to which the original question was referring but can tell you that when operating on contaminated runways bush flying raising the flaps can help prevent nice rock shaped dents in your flaps.
Also in many bush types my memory may be failing me here but I believe the Beaver and Twin Otter come to mind the flaps actually block the rear door. And if you were in the ditch you would be rather unhappy to find that the only door you could get out was blocked by the flaps.

I guess the procedure you use depends on each situation. I also find that in limiting cross winds the less flaps the better.

I personally would be less than happy having to sit through a hairy landing by my colleague if I thought they were not so much as capable of lifting a flap lever during a landing.

Many places worldwide seem to train with the sole objective being how can we fast track this 0 hr wonder to his first Boeing/Bus rating and they skip over the real learning and hand flying stages.

Interestingly when I did my PPL many years ago (in a PA-38) I was taught to use flaps to control the rate of descent when doing a glide approach.

If I were ever unfortunate enough to be facing a real forced landing, then in an A/C with manual flaps I'd fly the approach with one hand on the flap lever.

Hmmm, I would like to gently suggest several reasons why that's not so good:

Poor discipline, sideslipping is the accepted technique for this, not down and up with the flaps, particularly for flapless aircraft!

If you have applied a lot of flap for this technique, and you decide to stretch your glide, you're going to raise some of the flap, and suddenly raise you're stall speed. Very unsafe, if you were already slow, 'cause you were already stretching it in. If you slip and unslip, you're changing drag instantly, but leaving lift undisturbed.

If you get used to this "crutch for proper technique", you'll be buggered flying a plane with no, or electric flaps, particulary after an electrical failure.

There are planes with much more effective flaps than a Tomahawk (C-180, for example). Playing with the flaps up and down during a glide will be more dramatic in one of those types.

And lastly, if you really have to glide one day, you'll want to concentrate on flying with the primary controls, and having a free hand for the required securing of the cockpit. it should not be commited to the flaps.

I'd be surprised to see a flight manual that recommends this procedure....

PilotDAR, some excellent points there. I'd agree that slipping is usually the best way to lose a little excess height on approach, and indeed may be the only option if you are flying a flapless, brakeless taildragger. However, if for whatever reason you need to stretch the glide, slipping the aircraft won't help you and in some types (even some very large ones!), retracting some or even all of the flaps whist maintaining a safe airspeed might just make the difference between clearing the hedge and taking it with you. I think it's always a good idea to know as much as you can about the capabilities of your aircraft and knowing how it will behave if you retract the flaps in the glide at approach speed may give you an additional option that could just be useful someday. As has been said before, this is probably most useful if your type has simple manual flaps & it also helps if (like the PA-38) flap retraction won't cause a significant trim change.

At the time I was doing my own basic training (almost 30 years ago now) I remember my instructors didn't allow low hrs students to slip the aircraft (we were all taught the crab method for Xwind landings) yet seemed quite happy for us to mess around with flap settings in the way I've described. I guess I can see the logic of this - the tomahawk is perhaps not the safest of aircraft for the inexperienced to be flying slowly with crossed controls close to the ground.

As an Ag pilot I always lift the flaps on touchdown or slightly before. Alot of the strips we work off 'going around' is not an option. By lifting the flaps this ensures minimal float, it also gets the tailwheel on the ground and with this locked then using reverse (turbo prop) is an option if required.
The flap switch ( electric flaps) is located on the stick in the trigger position. This makes it easy to get to and doesn't require another hand.
Flying these planes, you are living on the flap switch, flaps for T/o, flaps to turn, flaps to climb, flaps to land. If your flaps stop working it is time to go home.
I don't think dumping the flaps on landing should be considered the norm but it is something worth demonstrating to your students in my opinion.
Especially useful trick in a taildragger in extreme x-winds.

I also learned to never retract flaps on final during my PPL training :=. Post-PPL I had some extra lessons with the CFI at the same school and got introduced to the secret of retracting flaps on final :ok:.

Retracting flaps on touchdown ....
 

Fine in theory, until you raise the gear by mistake ... as has been done all too many times by people trying to be slick ... in a word ... don't.
Plan the perormance, if the approach isn't right go around.

Retract flaps appears in the after landing checklist with the aircraft stopped clear of the runway, not as a fuzzy memory item.