Aerodynamics of the Base to Final stall

Seems like a slip in a base or final leg turn would be something to be avoided almost as much as a skid.

Additionally, I would argue that if you need to loose altitude with a forward slip in a pattern turn, you probably should try again. Maybe there are some scenarios on a tight field with obstacles in a fast plane that this would be necessary, but in general, I'm not seeing a good reason for it.

I can see a bit of a slip on final if you're in the pattern, but not during the turn. And a slip on a straight in, or to get down to pattern altitude makes sense (again, not turning).

But, I'm a new pilot, so always looking to see where my thinking is narrow.
 
Salty said:
Seems like a slip in a base or final leg turn would be something to be avoided almost as much as a skid.

Additionally, I would argue that if you need to loose altitude with a forward slip in a pattern turn, you probably should try again. Maybe there are some scenarios on a tight field with obstacles in a fast plane that this would be necessary, but in general, I'm not seeing a good reason for it.

I can see a bit of a slip on final if you're in the pattern, but not during the turn. And a slip on a straight in, or to get down to pattern altitude makes sense (again, not turning).

But, I'm a new pilot, so always looking to see where my thinking is narrow.
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Not really, but if you prefer to do it that way, there is nothing wrong with it.

A slipping stall is a bit more difficult to cause, and quite a bit slower, than a skidding stall.

Passengers don't like slips, especially in a turn, as it feels to them as though it's not in control.

Slips during a turn are fairly common for power-off 180s. As soon as you know you're definitely high (and you will be in a 172 if you start your turn right away), you can start slipping. Power off 180s do not allow you to "try again." It's a practice emergency maneuver, and adding power or going around prior to touchdown means you blew it. Slipping is allowed, even preferred, as approaching high and then losing altitude in a measured, controllable way is how you make the runway without risking an overrun (you can do it with flaps, too, but it's much less precise in a Cessna, since it takes too long to change them).

And some planes don't even have flaps. For those, slipping is virtually required on all approaches.
 
denverpilot said:
if you're trying to increase the sink rate aerodynamically, "step on the sky"...
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"Excuse me while I step on the sky..."

Big apologies to Jimi Hendrix. :D Seriously, that's a good way to remember it.
 
Salty said:
Seems like a slip in a base or final leg turn would be something to be avoided almost as much as a skid.
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Slips and slipping turns are safe, and are taught in Canada as part of the Transport Canada-approved curriculum.
Stalls out of slips take some doing.
 
Dan Thomas said:
Slips and slipping turns are safe, and are taught in Canada as part of the Transport Canada-approved curriculum.
Stalls out of slips take some doing.
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nose down....and speed up....and that configuration shouldn't be a problem. When folks get distracted and stop/ change the decent profile things can get unraveled.
 
It amazes me how little most pilots know about slips.

I had a student take his PPL check ride, DPE said to me, infront of my student, "he slipped for the short field landing", I said "..and", well this D P E said it wasn't the ideal way to do it, I mentioned to him that I taught my students to slip and to use that tool whenever they needed, or might need it, I further educated this DPE that many real world short field landings are due to there being stuff, like trees, on ether end of a runway, resulting in a steeper approach, a slip will minimize float and maximize the distance between where the plane stops and the end of the runway, I asked if he thought it would be better form to add additional risk to a landing by not using a slip, he back peddled.
 
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Maui Cirrus CFII said:
Good advice. However I believe practing 2 g accelerated stalls is a better exercise. 1 g is seat of your pants, but 2 g is a whole different feeling.
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I think the "Seat of the Pants" is part of the problem, What most people think is seat of the pants turns out to actually be visual cues. Which is why the low altitude downwind turns tend to be such a problem. I have personally experienced this and it feels just like the "leans" in IFR flying where you swear you are turning but are not and if you look away from the turn indicator you will start turning, only in this case it feels like you are going fast when you aren't. I have had two other pilots describe this also, one similar to what I felt, if he looked away from the Airspeed he would slow down, and he physically had to force himself to push the nose down. The other pilot said he thought something was jamming the elevator as it took so much force to push the nose down, he then stated "the subconscious can be a powerful thing".

The problem of course is we have yet to find a good way to safely simulate this illusion of speed when practicing slow flight or stalls.

Brian
CfIG/ASEL
 
Salty said:
Seems like a slip in a base or final leg turn would be something to be avoided almost as much as a skid.

Additionally, I would argue that if you need to loose altitude with a forward slip in a pattern turn, you probably should try again. Maybe there are some scenarios on a tight field with obstacles in a fast plane that this would be necessary, but in general, I'm not seeing a good reason for it.

I can see a bit of a slip on final if you're in the pattern, but not during the turn. And a slip on a straight in, or to get down to pattern altitude makes sense (again, not turning).

But, I'm a new pilot, so always looking to see where my thinking is narrow.
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The steep slip or slipping turn can be an excellent way to create drag for a steep approach without hanging flaps out, which take time to retract to remove the drag if you need to. It can be modulated way faster than anything but maybe Johnson Bar flaps.

Want max drag? Push the rudder to the floor. Want to remove it? Take pressure off the rudder. Then just bank appropriately and maintain the nose down attitude.

It's the ONLY way to do that in something without flaps, too. Or simulated stuck flaps -- which is a great way to make someone think about it and do it. Heheh. "Flaps aren't moving... how can we get down from here?"

A big ol' slip is a great tool for a close in steep approach without allowing the airspeed to climb to astronomical numbers.

My favorite place to use a strong slip is a simulated engine failure abeam or just before the numbers. Gear down (if you've got that), and roll into the turn immediately. Might as well stay close to the runway instead of having to fly a giant pattern and not know if you have the right energy to get back.

Slip hard on base, and as the gear starts making drag, you can judge the descent and remove slip in the turn as needed. (If retract gear...Three green...) Continue the turn, land. No other reconfiguration needed.

No flaps needed, thanks to aerodynamics. :)

Can even be a continuous slipping turn to final if needed. In fact if that's happening you probably have a crosswind from the downwind side and you're already set up to land with that wheel down.

Or if the engine out is simulated beyond the numbers, just turn straight to them. No need for square patterns in an emergency. Get back to the runway and then get down.

Simple as pie. Just takes practice. The only thing you have to get used to is the ASI won't be accurate.
 
Another good use of the slip is deliberately staying high and then flying a steeper approach, staying above the glidepath of that big ol' wake producing jet you are following. @denverpilot above mentions that your airspeed indicator will be inaccurate when slipping which is true. It can read higher or lower depending on which combinations of slipping into the static port, away from the static port, the effects of the fuselage "shielding" the pitot tube and the pitot tube being at an angle to the relative wind. Each model of aircraft has its own characteristics. High wing, low wing, static ports on one side or both etc etc.
 
Salty said:
Seems like a slip in a base or final leg turn would be something to be avoided almost as much as a skid.

Additionally, I would argue that if you need to loose altitude with a forward slip in a pattern turn, you probably should try again. Maybe there are some scenarios on a tight field with obstacles in a fast plane that this would be necessary, but in general, I'm not seeing a good reason for it.

I can see a bit of a slip on final if you're in the pattern, but not during the turn. And a slip on a straight in, or to get down to pattern altitude makes sense (again, not turning).

But, I'm a new pilot, so always looking to see where my thinking is narrow.
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Slipping turn all the way around and down to the runway. Can see the aileron deflection. No flaps, no forward visibility, no problem getting down quick. I do this every landing, just not necessarily quite this steep. Also makes it easy to get down ahead of and out of the way of "normal" airplanes in the pattern. ;)

 
dmspilot said:
Where does it say that? The cite is 10 pages. The word "block" appears 0 times, while the word "change" appears one time but in a different context.
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No reply to this. When his strawmen and other deceptive and disingenuous debate tactics don't work, he changes the subject.
 
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