Stalls full rudder crossed control

[ctfarmer]

Doing some stalls today in my CTLS with Bill, my CFI. One exercise we tried was fully crossed control stalls. Ie zero flap/closed throttle/full rudder (left or right)/crossed control forward slip and pull the stick back until it is fully stalled then further.

 

Interesting result. Instead of dropping a wing or doing anything alarming we just went into this slightly left or right turning porpoising nose down forward flight for as long as you would hold it in that configuration.

 

When i say porpoising - our attitude during the stall with stick right back was slightly nose down with rapid descent with a porpoising motion superimposed. Not steep nor violent but our flight resembled a smooth and repetitive porpoising sine wave motion with about a 2 sec period

 

With no control input changes, the nose would dip then recover repetitively. Amplitude was hard to judge but we experienced smooth very clear up and down pitching as we followed the curve quite unlike turbulence where the planes attitude largely remains the same.

 

Bill (a commercial pilot for almost 50 years and 10,000's hrs in commercial airline industry) is amazed and wonders how this is achieved aerodynamically as he assured me we would be our back in the schools Tecnam P2008 or Foxbat.

 

 

 

cheers peter

[Jim Meade]

Just to be sure I understand, you have the rudder to the floor and the stick to the opposite side and full back? At first reading I thought maybe the stick was centered and full back, but upon further review decided you had the stick to the opposite side.

 

I don't think my CTSW acts this way. I don't get the rapid descent and porpoising as I recall, but I'd have to go out and do it again to be sure.

[ctfarmer]

Jim,

 

Just to be sure I understand, you have the rudder to the floor and the stick to the opposite side and full back? 

 

That is the correct.

[Ed Cesnalis]

if you're abrupt does it snap? 

[ctfarmer]

if you're abrupt does it snap? 

 

We did not try it with abrupt moments.

[Tony & Rose]

I can get the 'porpoising' you mention; and I've just considered that as the CTsw attempting to correct, or recover from potential stall. That configuration (short of stalling) is our normal set for a rapid controlled decent. (Works in any flap configuration, although we limit ourselves to zero or 15 degrees) 

Charlie: With an abrupt movement, we get what you would expect, but nothing that increases the heart rate. If you 'stay' with it I've let it move to the 60 degree range, but it wasn't a 'quick-fire' shot....  Plenty of time to think it through...

[Ed Cesnalis]

Thanks Tony

[FlyingMonkey]

I have not seen porpoising in my CT.  If I smoothly go into a power off stall and continue to hold the stick back after the break, the airplane just goes into a steady rate descent of 700-800fpm with the stick full aft.  There is no tendency to roll off on one wing, as long as I maintain the ball in the center.  Maybe if I was more aggressive in entering the stall I would get some nose bounce.

[GravityKnight]

Hopefully I don't steer this thread in an unintended direction...

 

But what's the Foxbat like? I really like the a22, it has some seriously good characteristics on paper, and I've seen positive videos and talk about flying one. Just curious for your (or anyone with experience) thoughts on the foxbat?

[FlyingMonkey]

Hopefully I don't steer this thread in an unintended direction...

 

 

 

Squawking 7500.  

[ctfarmer]

I have not seen porpoising in my CT.  If I smoothly go into a power off stall and continue to hold the stick back after the break, the airplane just goes into a steady rate descent of 700-800fpm with the stick full aft.  There is no tendency to roll off on one wing, as long as I maintain the ball in the center.  Maybe if I was more aggressive in entering the stall I would get some nose bounce.

 

Andy,

 

Only occurred in my CT with crossed controls - we had full rudder input and aileron to maintain a straight flight path then pull stick back until stall. Normal stalls in my CT are exactly as you describe.

 

 

peter

[FlyingMonkey]

Andy,

 

Only occurred in my CT with crossed controls - we had full rudder input and aileron to maintain a straight flight path then pull stick back until stall. Normal stalls in my CT are exactly as you describe.

 

 

peter

 

Got it, thanks.

 

I'm hesitant to try the cross controlled stall you described...Isn't that a perfect setup for a spin entry?  Or do the outside ailerons keep the inside rudder deflection from rolling the plane over?

[Ed Cesnalis]

In this configuration you are begging for a spin entry, especially if it is full left rudder, but with a CTSW begging is not always quite enough.  Tony confirms above that he can enter a spin (snap roll) if he is abrupt when positioning the controls. 

 

Bringing the nose up much higher in order to approach stall will make things more exciting as well.

[bitten192]

Cross control stalls is a recipe for a spin. Be careful.

[Ed Cesnalis]

Cross control stalls is a recipe for a spin. Be careful.

 

I think the whole point of this thread is that it is surprising that the CTSW is this reluctant to spin.  My guess is that the tadpole shape provides a  big opening for wind to cross over in front of the tail as opposed to impacting the fuselage and causing less yaw moment.

 

A CTSW isn't very picky about flying with its nose into the wind, a little off has little effect except on fuel management. 

[FlyingMonkey]

POH states that spin recovery is conventional...has anybody actually put a CT in a fully developed spin (inadvertently of course) and recovered, and can report the airplane's behavior?

[FlyingMonkey]

In this configuration you are begging for a spin entry, especially if it is full left rudder, 

 

Why is left rudder more dangerous than right?  A friend who slipped my CTSW in both directions said that when he slipped the airplane using left rudder he noticed burbling that he though might indicate the airplane might be less stable and more prone to stall/spin in that direction.  When I slip in mine I tend to do so using right rudder and left aileron, so I can better see where I'm going out the pilot side window.

[Ed Cesnalis]

Why is left rudder more dangerous than right?  A friend who slipped my CTSW in both directions said that when he slipped the airplane using left rudder he noticed burbling that he though might indicate the airplane might be less stable and more prone to stall/spin in that direction.  When I slip in mine I tend to do so using right rudder and left aileron, so I can better see where I'm going out the pilot side window.

 

Various forces like torque, p-factor and  Gyroscopic Precession provide left turning or yawing tendencies, so going left you are aided by these forces instead of overcoming them.

 

A good exercise ( instructor and chutes ) is to simulate a base to final turn where you limit your bank and yaw your nose left to not overshoot.  It is surprising how easily you can enter a spin doing this.

[Ed Cesnalis]

POH states that spin recovery is conventional...has anybody actually put a CT in a fully developed spin (inadvertently of course) and recovered, and can report the airplane's behavior?

 

 

It is difficult to talk about maneuvers on this forum these days.  Someone will quickly point out any resulting infractions and request that you post a video for evidence.

[Anticept]

Tried a power off stall with with full rudder deflection. Wing dropped hard, nose followed with yaw, but it didn't spin. Came out just shy of 90 degrees from previous heading. Decided not to try again because the harder a plane is to enter a spin, generally it's harder to get out of.

[FlyingMonkey]

It is difficult to talk about maneuvers on this forum these days.  Someone will quickly point out any resulting infractions and request that you post a video for evidence.

 

Understood.

[Al Downs]

How much fuel is in the airplane when doing this? It seems this would be a factor

[ctfarmer]

How much fuel is in the airplane when doing this? It seems this would be a factor

 

In my case, pilot copilot, ~80kg (170lbs) each and 60 litres (15USgals) fuel.

 

I agree with previous posts and have no intention of trying crossed control stalls myself without a very experienced pilot with me.

[Ed Cesnalis]

....  When I slip in mine I tend to do so using right rudder and left aileron, so I can better see where I'm going out the pilot side window.

 

I'm not concerned when I'm slipping, skidding is how I enter a spin,   Too much bank is ok, too little is risky, right?

[FastEddieB]

While its fun and educational to nibble at the corners of a plane's flight envelope...

 

...just a word of caution in doing so in a plane not approved for intentional spins.

 

These little guys can "bite" in very shocking ways if provoked. Spin recovery should be possible, but may not be intuitive or immediate.

 

I have taught hundreds of cross-control stalls in Cessnas and Citabrias. They can nearly roll inverted in that first windup to a full spin.

 

Key is, they were all approved for intentional spins. And with spins in those I have a lot of experience.

 

I would be hesitant to horse around my Sky Arrow in such a fashion - its placarded against intentional spins and I have no idea what a pusher with a t-tail would be like in a spin. And don't really care to play test pilot and find out.

 

But I do not mean to admonish anyone - just make sure you have a LOT of altitude. It may take quite some time and experimenting with different control inputs to get out of a spin in one of these little guys. And there's always the remote possibility of some sort of stable, oscillating or flat mode from which the chute would be the only way to survive.