What happens during a slip on final?

[denverpilot]

It's almost impossible to achieve it even with the CH701:

Dan

That guy bend any metal with that tailstrike?

 

[RotorAndWing]

I always thought a nice slip was kinda graceful. No pun intended

Back when I was flying B727's I've slipped it many times, no big deal.

 

[VanDy]

Nope. Not even close. The typical taildragger is about five degrees short of stall angle when in the three-point attitude. Most airfoils will stall at around 17 degrees;

Dan

I have no idea the actual degrees, but with the Tcraft it is very easy to land tailwheel first, and some of my best landings I feel the wheel hit the grass just a moment before the mains.


-VanDy

 

[Dan Thomas]

I have no idea the actual degrees, but with the Tcraft it is very easy to land tailwheel first, and some of my best landings I feel the wheel hit the grass just a moment before the mains.


-VanDy

I've done that in several different taildraggers. I once watched a friend fly down the runway in a Piper Clipper with the tailwheel on the ground and the mains a foot or more in the air.

Dan

 

[Dan Thomas]

That guy bend any metal with that tailstrike?

Probably. Pretty hard to do that and not beat up some skin. Should have a springy tailskid under it.

Dan

 

[azure]

Back when I was flying B727's I've slipped it many times, no big deal.

But don't EVER slip a 172 with 40 degrees of flaps.

 

[RotorAndWing]

But don't EVER slip a 172 with 40 degrees of flaps.

The 727 had a 40 degree flap lock out, so we were limited to 30 degrees.

 

[redtail]

I have no idea the actual degrees, but with the Tcraft it is very easy to land tailwheel first, and some of my best landings I feel the wheel hit the grass just a moment before the mains.


-VanDy

I don't have a ton of TW experience (just got the endorsement last year), but on my first three point landing, the tailwheel touched first.

Then one of my wheel landings turned into a three point because I got too slow

 

[flyingron]

A. The design of the three point attitude of a TW aircraft is exactly at the stall AoA at the stall speed.

BULL. Stall AOA does not change with airspeed. While I suspect it's possible that some bizarre bird sit at a stall attitude, everyone I've ever flown is NOT. It certainly would be difficult to control.

B. The landing flare in a TW aircraft is set up so that when the wheels touch, there is no more remaining lift(you are stalled)

This is where you make your mistake. Where you no longer have lift to maintain level flight once again *IS NOT* the stall.

C. Unless you have a very powerful engine, and a very light load, you will not be able to maintain 'level flight' once stalled. Also a stall can be entered at many attitudes and speeds but it is not germane to the discussion of this case.

But the REVERSE IS NOT TRUE. You can be descending while NOT stalled. It's a normal flight regime and includes your alleged full stall landing.

 

[redtail]

...and speaking of slips. I don't think I knew what a real slip was prior to flying the Super D.
Practicing forward slips in that plane was a blast! I had never seen that amount of rudder authority before.

On my first one, the instructor had to say "stand on the right rudder". I thought I was already standing on it.

 

[Dan Thomas]

...and speaking of slips. I don't think I knew what a real slip was prior to flying the Super D.
Practicing forward slips in that plane was a blast! I had never seen that amount of rudder authority before.

On my first one, the instructor had to say "stand on the right rudder". I thought I was already standing on it.

Used to have fun with that, teaching 172 pilots to fly Citabrias. The 172 barely even has a rudder.

Dan

 

[alfadog]

Used to have fun with that, teaching 172 pilots to fly Citabrias. The 172 barely even has a rudder.

Dan

I had to slip the 172 "hard" last weekend as I was letting the right seat fly and we were way high on final. Wow. Quite interesting after flying the Luscombe. The 172 takes a lot of rudder effort for very little result.

 

[Silvaire]

That guy bend any metal with that tailstrike?

I'm pretty sure that's a take-off, not a landing.

 

[Skylane81E]

Used to have fun with that, teaching 172 pilots to fly Citabrias. The 172 barely even has a rudder.

Dan

Then what does a PA28 have?!

Good golly I couldn't get that thing to slip for anything.

Granted I am used to my 182 that decidedly does have a rudder. Likely not the most affective one in the world but it defiantly works

 

[Skylane81E]

I'm pretty sure that's a take-off, not a landing.

Regardless I'm sure his rudder didn't appreciate the treatment

 

[Silvaire]

Then what does a PA28 have?!

Good golly I couldn't get that thing to slip for anything.

Granted I am used to my 182 that decidedly does have a rudder. Likely not the most affective one in the world but it defiantly works

The Cherokees have full time, direct nose wheel steering and I guess that's why they put a big fin on the back of the nose wheel faring, take that wheel pant off and you lose half your rudder authority

 

[Skylane81E]

The Cherokees have full time, direct nose wheel steering and I guess that's why they put a big fin on the back of the nose wheel faring, take that wheel pant off and you lose half your rudder authority

I noticed, I was high on final in a Warrior, thought "no problem, I'll just fwd slip it"

Full right rudder, some left aileron and not much really happened. Oh well it is about my only gripe with how the thing flies.

 

[dmspilot]

something like a decathlon with a symmetrical wing would probably eventually end up in a spin.

I did some stalls in a slip in a Decathlon during my CFI spin training. No spin.

The Airplane Flying Handbook actually mentions this:

"Unlike skids, however, if an airplane in a slip is made to stall, it displays very little of the yawing tendency that causes a skidding stall to develop into a spin" (page 8-11).

However, it contradicts itself several times.

 

[gismo]

My landings in a tailwheel plane generally include a full stall about 1/32" above the runway. Well, at least that's my goal.

And welcome to the OP. You'll get plenty of fact-based advice here. Some of it might even be right.

Most taildragger pilots think they're stalling above the runway but the truth is many if not most taildraggers require an AoA noticeably higher than what the 3 point attitude provides in ground effect. In reality you simply reach the point where the airflow over the wing is insufficient to create enough lift to support the airplane and it settles to the runway. You can see at this altitude if you perform a stall from level flight while looking out the side to see your pitch attitude. I think you'll discover that the pitch attitude is considerably higher then than what you have sitting on the ground.

 

[comanchepilot]

The old wives tales are absolutely astonishing . . .

You are not 'broadside' to the 'air flow' at any time - yes, you are flying at an angle to relative wind, but its not 'broadside.'

Slips on final are the same as slips anywhere else. . . . the airplane has no idea its on final.

Stall speeds do not change - unless you are adding some pull to maintain altitude for some reason - if that is the case - just take out some bank and use more crab.

Slips are great way to learn 'fine' aircraft control and learn in a cross wind to land on the upwind wheel to keep the airplane pointing forward as well as kick out the rudder correction but before nose wheel touch down to prevent darting -

Slips are great bit of skill to recover from poor planning of ATC or the pilot in the event you are too high approaching an airport -

you will not do them in big airplanes because it freaks out the passengers aft of the wing. . . .

When it comes to stalling it on . . . the proof is often in the pudding when you land and you hear the stall warning - you're generally +5 knots from stalling - add into that mix the reduction of drag from being in ground effect - and you are prob a good 10-15 knots from stalling at that point in a light twin or single.

 

[dell30rb]

+5 knots from stalling - add into that mix the reduction of drag from being in ground effect - and you are prob a good 10-15 knots from stalling at that point in a light twin or single.

Its my understanding that ground effect just affects drag and makes it take longer to bleed off that few knots above stall when you hear the stall warning. Ground effect does not increase your stall speed. The stall warning functions off of angle of attack, if you are 5 knots above stall in level flight when it sounds at 200 agl you are 5 knots above stall in level flight when the horn goes off at 3 agl

 

[ChrisK]

You are not 'broadside' to the 'air flow' at any time - yes, you are flying at an angle to relative wind, but its not 'broadside.'

As you said, the nose is not pointing directly into the relative wind, presenting a larger footprint to the relative wind, creating more drag. Sure, "broadside" might be an extreme exaggeration, but I think it is a good conceptual mnemonic.

 

[denverpilot]

If you take a Cessna up to cruise altitude and a slow cruise airspeed and push a rudder to the floor while keeping the wings level, you can see by the resulting turn rate just how wimpy the rudder really is.

It'll also dispel any sense of putting it "broadside" since you see just how little you can overcome the slipstream effect over the rest of the fuselage.

Of course, do this at a reasonable speed with enough power to go around in big broad skidding circles with a bit of drag. Below Va would be prudent too, of course.

Just a boring little exercise to see how wimpy the rudder is. In most common Cessnas anyway.

(Granted an L-19 might be a but more energetic if you're looking for a Cessna with a touch more rudder authority than typical. )