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Suppose I'm making a turn from a left base to final and, realizing I need to kill quite a bit of excess altitude, decide to use a forward slip with full rudder deflection (along with full flaps).

Which direction of rudder deflection would be preferable?

I suppose that yawing left would result in less bank and therefore a lower load factor, which may be safe at low speed and low altitude. But yawing right, will result in a steeper bank which (under the same IAS) will result in an even higher rate of descent thereby getting me to the ideal glide slope earlier and leaving more time to fully stabilize before the threshold.

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  • $\begingroup$ GJ, would you please elaborate on your comment of AOB being more or less in the different directions? Because you control AOB... Also, my first impulse is that it really doesn't matter, choose the direction that gives you best visibility and is suited to left/right handedness, but then I considered that precession, P-factor, slipstream, etc. may make one preferable over another, but I haven't heard anyone else mention it. (only general cautions about slipping in a turn) What factors should we consider?... $\endgroup$ – Michael Hall May 29 at 23:17
  • $\begingroup$ @MichaelHall sure, the idea is that the particular turn radius needed for aligning with the runway could be achieved either by a low AOB skid (yaw left in the example) or high AOB slip (yaw right in the example). $\endgroup$ – GJ. May 31 at 11:27
  • $\begingroup$ Ok, I understand now. I would agree with the others then, don’t start your slip until out of the turn, $\endgroup$ – Michael Hall May 31 at 14:37
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I use slipping turns all the time.

If you want to do a slipping turn you yaw the nose OUT of the turn, being careful to keep G loads low. It's NOT a dangerous maneuver if you keep speed up and nose down while doing it although you should use a bit more aggressive nose down than in a straight side slip to account for the slight extra G from the turn. If you keep the wings largely unloaded and let the airplane fall semi-ballistically, you aren't going to stall.

To do it safely however, you do have to know how to fly the plane.

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    $\begingroup$ I agree. In gliders we routinely practice slips the full length of the pattern, including turns, to simulate failed spoilers. In fact I was required to do this during my FAA practical test. Yawing away from the runway ensures you are always banked toward the runway (straight and turning). It's exciting - noisy, shaking, airspeed reads zero, sight lines changed - but I tell myself "the wings don't know the plane is slipping". Just be sure to keep the airspeed up. Needless to say, you learn this at altitude then do the pattern with an instructor. $\endgroup$ – idoimaging May 29 at 16:08
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Don't do either until you are on final. Otherwise you can get into an uncoordinated mess and possibly stall, or worse snap roll the airplane, and without sufficient altitude to recover, you're hitting the ground hard. Possibly fatally.

Once on final it depends on where the wind is coming from. Straight ahead or from the left, I like dropping left wing & adding right rudder so I can see better.

Wind from the right, you need to drop the right wing and add left rudder.

Try your suggestion 2000-3000 ft above ground level first. Go find a road to follow as a runway and see what the plane does. If it simply stalls, we've been trained as Private Pilots how to recover. Something more severe, ask a local instructor what to do.

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    $\begingroup$ Totally agree. Turns in the pattern need to be fully coordinated and "flying straight". Only after you've completed the turn, gone wings-level, and stabilized can you properly judge what maneuver to do, to what degree, and execute it safely. $\endgroup$ – abelenky May 28 at 21:38
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Slipping turns are not inherently dangerous. NEVER do a skidding turn, with nose yawed in same direction as bank (i.e. pilot is holding low-side rudder), anywhere near the ground. It is an invitation to a stall-spin accident.

If you want to wait till you are beginning final approach to begin the slip, AND wind is not a factor, it makes sense to keep some of the bank that you had from your base-to-final turn and then cancel the turn rate with opposite rudder, i.e. top rudder. Obviously, you can't do a non-turning slip by applying rudder in the same direction as bank.

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Rudder opposite the bank always. Maintain a safe airspeed for the conditions. Be familiar with the airplanes handling.

If you need to know your safety margin, hire an instructor and ask for training at a high altitude that would allow for spin recovery in an aircraft approved for spins to see at what airspeed the plane will stall in a full turning sidedlip.

Ensure your real, pattern altitude, turning slips are done well above that speed.

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"Supposing I'm making a turn from left base to final, and realizing I need to kill quite a bit of excess altitude" 4th Edition

Pushing the rudder into the turn is not an option due to stall/spin risk.

An aileron slip while turning is possible. To execute the maneuver, one would carefully increase roll to the left (left pattern) without increasing load on elevator, resulting in an increased rate of descent. The inside aileron goes up more, the outside down. Your approach speed is kept at a safe margin over stall.

What could go wrong?? If you practiced a simulated approach well above AGL, you would know!

The slip maneuver is safer for aircraft with low wing loading and ample tail volume as the tail will naturally lower the nose with increased VV and the wings will help reduce VV when you roll out. With practice, you do these all day long in a glider.

If you are flying a "brick", VV can get out of hand and high loaded wings will be much more prone to stalling if care is not taken to monitor VV, limit slip angle, and unload or even pitch down elevator while rolling out.

In all cases, the "round out" should start at a higher altitude due to the higher angle of descent (power on low angle landing can be "greased in" with hardly any round out at all).

Try it first at altitude. Practice makes perfect,

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