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Patrnflyr

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Isn't it simpler?  You will spin from a skid but not a slip, right?  The yaw input needs to be towards the turn not away from it.

 

 

You can spin in either direction, but the skid is much easier/faster to spin since the wing that is already high wants to come over the top.  You can spin from a slip, but the low wing has to come all the way up and over.  Simply not going to happen unless you're essentially asleep at the controls.

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Cluemeister noted that rudder should not be used to hurry or sharpen a turn which  is a great rule, rudder can't hurry or sharpen (skid) the turn beyond being coordinated.  Sometimes coordinated is too clean/efficient and it is ok to use the rudder to slow or prevent (slip) the turn.

 

An interesting exercise is to fly a whole pattern in a slip.

 

On this topic in other threads & forums I have posited the following thought experiment:

 

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One way to virtually eliminate the base-to-final stall spin accident *might* be for instructors to advocate a "flat foot" policy.  This would mean that in the pattern and until established on final, the pilot is taught to keep their feet off the rudder pedals.  Not necessarily flat on the floor, but definitely no pressure on the pedals.  What would that accomplish?

 

When making turns around the pattern, the airplane will likely be uncoordinated, slipping around the turns due to adverse yaw.  Not the most efficient or elegant way to fly.  However, it means that in the base to final turn (or anywhere else, for that matter), the airplane essentially cannot get into the worst pro-spin condition (slow speed, skidding turn).  An incipient spin would still be possible from the slipped condition in a turn if the airplane got slow enough, but that would be easily corrected by lowering the nose and using opposite rudder (another reason not to fully take feet off the pedals).

 

Once the airplane is on the centerline of the runway, the pilot could again begin using the pedals to keep alignment and correct for crosswind.

 

As mentioned, there are some downsides to this, primarily as mentioned that this is "inelegant".  But from a safety perspective, it might make sense.

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I'm not advocating the above, it's just presented for your consideration.  I did have a CTSW instructor though, who was in a previous life an F-104 pilot for the German Air Force, who advocated *not* using rudder in turns when doing low level maneuvering, especially if aggressive turns and/or low speeds were needed.  His reasoning is that it's just too easy and tempting to skid to make more aggressive-appearing turns, and when at low level your attention is outside (where it should be), and not on the location of the ball.

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Charlie,

 

I liked to introduce all my students to a cross-control stall prior to solo.

 

Why? I accidentally got into one on an early solo and it scared me pretty badly.

 

The setup for a demo was a departure stall with feet on the floor. When full power was added, the necessarily right rudder was intentionally not added. To keep the plane from turning, opposite aileron was used. So, by definition, when the stall broke the plane was in a slip - too much bank (though small) for the rate of turn (which was zero).

 

At the stall break a dramatic left wing drop can easily develop, leading to a spin if not recovered from promptly.

 

So, that would qualify as a spin from a slip, albeit with power effects.

 

Right?

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I have never entered a spin from a slip, sounds dramatic.  Do you have a video of such an entry?

 

I have. As I mentioned earlier as a student I had the opportunity to do lots of spins. If you are slipping the airplane will rotate over the top, instead of falling into the turn. It should be much easier to catch and stop. Of course we were aggravating the spin by holding pro spin control inputs. 

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On this topic in other threads & forums I have posited the following thought experiment:

 

---

One way to virtually eliminate the base-to-final stall spin accident *might* be for instructors to advocate a "flat foot" policy.  This would mean that in the pattern and until established on final, the pilot is taught to keep their feet off the rudder pedals.  Not necessarily flat on the floor, but definitely no pressure on the pedals.  What would that accomplish?

 

When making turns around the pattern, the airplane will likely be uncoordinated, slipping around the turns due to adverse yaw.  Not the most efficient or elegant way to fly.  However, it means that in the base to final turn (or anywhere else, for that matter), the airplane essentially cannot get into the worst pro-spin condition (slow speed, skidding turn).  An incipient spin would still be possible from the slipped condition in a turn if the airplane got slow enough, but that would be easily corrected by lowering the nose and using opposite rudder (another reason not to fully take feet off the pedals).

 

Once the airplane is on the centerline of the runway, the pilot could again begin using the pedals to keep alignment and correct for crosswind.

 

As mentioned, there are some downsides to this, primarily as mentioned that this is "inelegant".  But from a safety perspective, it might make sense.

---

 

I'm not advocating the above, it's just presented for your consideration.  I did have a CTSW instructor though, who was in a previous life an F-104 pilot for the German Air Force, who advocated *not* using rudder in turns when doing low level maneuvering, especially if aggressive turns and/or low speeds were needed.  His reasoning is that it's just too easy and tempting to skid to make more aggressive-appearing turns, and when at low level your attention is outside (where it should be), and not on the location of the ball.

 

Andy, As an instructor I think this is a horrible idea. While this might work for the CT and some other airplanes an instructor must teach the student flying basics that apply to all airplanes. I've flown some airplanes that the no feet process would make turns very uncomfortable, if not impossible. These were not some rare or exotic airplanes, but training aircraft from days gone by. A couple are so bad that if you add aileron without rudder the nose will swing the opposite way and the airplane just plows straight ahead on the same track.

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Andy, As an instructor I think this is a horrible idea. While this might work for the CT and some other airplanes an instructor must teach the student flying basics that apply to all airplanes. I've flown some airplanes that the no feet process would make turns very uncomfortable, if not impossible. These were not some rare or exotic airplanes, but training aircraft from days gone by. A couple are so bad that if you add aileron without rudder the nose will swing the opposite way and the airplane just plows straight ahead on the same track.

 

As I mentioned, not advocating, and clearly airplane dependent.  But just a thought experiment on some fool-proof techniques for avoiding this common problem.

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Why? 

I don't see what you're driving at.

 

I fly out of an airport with a lot of jet and turbine aircraft adjacent to 13,000' terrain and it can be interesting trying to avoid them.  The pattern is 8,000' but many fly downwind at 13,000'.  I learned in my 2-stroke powered Challenger that a very steep approach from the wrong side of the pattern was a way of quickly getting down and landing without conflict from planes going 100kts faster than me.

 

Even in my CT I sometimes hide in a mountain canyon adjacent to the field (there are a couple to choose from) and when there is an opportunity I get on the ground quickly to avoid conflict with the faster planes.

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Runway 27 is right traffic, on a BFR in my old Skyhawk the CFI wanted me to land on 27 without using a final approach.  The drill was to turn base without going beyond the numbers, slipping from downwind all the way to touchdown, descending just above the falling terrain,  and landing short enough to make the first turnoff. 

 

I'm not sure why he had me do that but I did learn that I didn't necessarily need a final approach leg and that I could get from abeam the numbers to exiting the runway in a very short time.

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As I mentioned, not advocating, and clearly airplane dependent.  But just a thought experiment on some fool-proof techniques for avoiding this common problem.

 

Andy, there are no fool proof techniques, unless they are built into the airplane like a Ercoupe. As long as the airplanes we are flying have independent controls on all 3 axis pilots will need to learn how to make coordinated turns. This is a basic skill that needs to be taught from the beginning.

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I was always taught and have advocated the following:

Just fly the airplane by the numbers and keep it in trim.

Works for me.

 

Bill, I agree with your approach (no pun intended) and I do the same.  But I can't help but wonder if practicing an uncoordinated stall and spin with enough altitude might be good practice so we develop the muscle memory and instinct to recover more quickly?  It's one thing to do power-on an power-off stalls in coordinated flight (usually an undramatic event), but I imagine uncoordinated stall/spin require fast rudder and stick/yoke forward work?  

 

I'm just guessing as a student pilot, but would love to get the thoughts of the more seasoned aviators here.

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Andy, there are no fool proof techniques, unless they are built into the airplane like a Ercoupe. As long as the airplanes we are flying have independent controls on all 3 axis pilots will need to learn how to make coordinated turns. This is a basic skill that needs to be taught from the beginning.

 

Everybody agrees it needs to be taught from the outset, yet these accidents keep happening.  We can't stop pilots from making mistakes, but maybe we can make it harder for those with marginal skills to "eff it up".

 

Maybe a rudder/aileron interconnect like the Ercoupe, but with an on/off lever?  A control mixer would interconnect the rudder to the ailerons in the pattern, but could be turned off when established on final?

 

That way in normal flight you have full three-axis controls, but when in the pattern or maneuvering down low you can set the lever to "auto" mode and the rudder coordinates with the ailerons via the mixer and making the airplane Ercoupe-style spin proof.  When you are on final you flip the lever back to "manual" and you again have full authority.  use of the lever would be completely at the discretion of the pilot and their comfort/experience level.

 

Again, just throwing out ideas since "just learn how to do it right" seems to be failing a lot of student pilots.

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Such a linkage becomes a failure point in itself.

 

Basically, i think the answer is better training. An instructor could have the student do turns at a safe altitude and try to line up with a road, and purposely start introducing bad input to see if the student can quickly identify and react. We have always being taught how to do it right, but what about how to correct when something goes wrong?

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To take it a step further . . . by "flying by the numbers" and making it a habit to stay in trim . . . anything other than that (excluding training) makes me feel uncomfortable. When something makes me feel uncomfortable, I become much more alert and pay closer attention to what is happening. In other words, more situationally aware. Errors I have made in the past can mostly be attributed to two things, poor situational awareness and/or complacency.

 

Accidents don't just happen as a result from single errors. They are an accumulation of errors. An accident is the culmination of a chain of events.

 

I agree.  Just for clarification, by "staying in trim" you're using another way to say "staying in coordination", right?  Just want to make sure I'm not missing anything in what you are saying.

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Such a linkage becomes a failure point in itself

 

The early model Cirrus' had rudder/aileron interconnect to some extent. Literally a bungee cord. It had a failure mode where someone "boxed" the controls on the preflight checklist and the whole mess jammed at full deflection.

 

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Small video here:

 

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]

 

Really Mickey Mouse in my book.

 

Even when working right, pilots complained of "dead" control feel. I never really minded it on mine, but some think the lack of "feel" may contribute to cross-control situations.

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The early model Cirrus' had rudder/aileron interconnect to some extent. Literally a bungee cord. It had a failure mode where someone "boxed" the controls on the preflight checklist and the whole mess jammed at full deflection.

 

Small video here:

 

]

 

Really Mickey Mouse in my book.

 

Even when working right, pilots complained of "dead" control feel. I never really minded it on mine, but some think the lack of "feel" may contribute to cross-control situations.

 

ಠ_ಠ

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I think you need and extra "not" in there somewhere!

 

I'm not a Luddite, but sometimes K.I.S.S. applies - each extra system is an added point of failure/maintenance/expense/weight issue.

 

On the Cirrus site, two recent accidents occurred because of fuel starvation - the pilot running a tank dry by forgetting to switch tanks. Many there call for idiot-proof* auto switching systems or a different warning system or whatever. In my mind its just a simple matter of training. If a pilot needing to switch tanks makes the whole endeavor too difficult, maybe he or she needs a different hobby!

 

*Of course, that only works until a better idiot comes along!

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I often hold right rudder when turning left crosswind and I wouldn't want some dome linkage preventing that.  I don't just use my rudder for coordinating with flaperons only but also with throttle changes, climbs and descents.  I would feel really dumb with my feet flat on the floor and a steering wheel in my hands.

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Everybody agrees it needs to be taught from the outset, yet these accidents keep happening.  We can't stop pilots from making mistakes, but maybe we can make it harder for those with marginal skills to "eff it up".

 

 

 

I am hopeful about technology advances like Garmin's envelope protection on the G3X.  It provides resistance on the stick to keep you in a safe envelope.  But don't know how that would help in a situation where you're not banked enough already, and you compensate with rudder.

 

I believe technological advances will make the big difference in the future.  Just as airbags, antilock brakes, and safety cages have reduced the automobile fatality rate.

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AoA indicators would probably help a lot with this issue as well.  You can't spin it in without stalling first.  This is probably one of the reasons FAA has gotten much more permissive about AoA installations.

Lots of discussion on the topic of spin here but you hit on the simple truth.  Don't fly too slow for your flight conditions.

 

Also, AOA indications are displayed on the Dynon 1000's screens in the two CT's I fly.  Don't know when they first showed up in the CT line, but I use them all the time. 

 

They are a very useful and simple display.  I first used them when flying the A-4 and don't know why Angle of Attack indicators aren't more prevalent in general aviation.

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