Cross-Controlling the Airplane

[Old Pilot]

After I learned how to land  my  Pitts S1 nothing bothered me anymore. I also have never been in a  position that I had to slip my Mooney. It's been a long time (over 20 years) since I have been flying so maybe some things have changed.

[Shadrach]

3 hours ago, M20F-1968 said:

Calculating the stall speed in a cross-controlled condition is a more complex equation than simply adjusting the stall speed for landing weight.

Can someone share the math?

In uncoordinated flight, it would seem that the stall speed at each wing tip might be different.  The angled linear cross-section of the wing seen by the wind at any point is much the same, but the functional area across the wing length is different (one side using more of the tip and one side using more of the root) This math is above my pay grade.

Do these hypothetical (or real) concerns minimize when you apply the rudder opposite to the aileron to line up with the runway (assuming the wind is lined up with the runway)?  Again, the math is above my pay grade.  

Any insights?

John Breda

It's not as much about math as it is the location of the instrumentation and load. The pitot tube on the left wing driving the ASI tells you little about the airflow over the right when in asymmetric flight.  The consequences of uncoordinated flight are many.  Asymmetric airflow due to blanketing, Yaw, turning, banking etc...means Asymmetric stall.  Not all cross controlled stalls are the same.  Stalling in a skid is far more dramatic than stalling in a slip.

[midlifeflyer]

5 hours ago, carusoam said:

Some People I would invite for that discussion…. @donkaye @midlifeflyer @KSMooniac

a collection of great CFIIs and an engineer…

Best regards,

-a-

Cockpit math above my pay grade.

[ilovecornfields]

2 hours ago, Old Pilot said:

After I learned how to land  my  Pitts S1 nothing bothered me anymore. I also have never been in a  position that I had to slip my Mooney. It's been a long time (over 20 years) since I have been flying so maybe some things have changed.

Winds are stronger now than back when you were flying. And YouTube has mostly replaced CFIs.

[Jerry 5TJ]

44 minutes ago, ilovecornfields said:

Winds are stronger now than back when you were flying. And YouTube has mostly replaced CFIs.

When I was a kid most cars had tail fins, so perhaps the winds were stronger then, not now?   

[Fly Boomer]

4 hours ago, A64Pilot said:

If you want to slip all the way down just keep speed up a little.

I like this plan best.  If you are not demanding much lift from the wing, it's harder to stall.

[Shadrach]

17 minutes ago, Fly Boomer said:

I like this plan best.  If you are not demanding much lift from the wing, it's harder to stall.

Words to live by when maneuvering at low altitude…

[Jerry 5TJ]

20 minutes ago, Fly Boomer said:

If you are not demanding much lift from the wing, it's harder to stall

Stall speed decreases as the square root of the g load, right?   So pitch to zero g and you can’t stall. 

[Fly Boomer]

2 minutes ago, Jerry 5TJ said:

Stall speed decreases as the square root of the g load, right?   So pitch to zero g and you can’t stall. 

Well, that may be true, but your altimeter may be spinning like a cartoon clock.

[ilovecornfields]

2 hours ago, Jerry 5TJ said:

When I was a kid most cars had tail fins, so perhaps the winds were stronger then, not now?   

And nuclear fusion was 20 years away, right?

[RLCarter]

Cross controls (slip) isn’t the issue, it’s a skid (too much rudder) that will roll you on your back. In a slip the wing opposite the direction of roll will stall 1st, rolling the aircraft level, in a skid it’s just the opposite and wing tucks under very quickly. Base to Final stall/spins are generally caused by overshooting the extended centerline and pulling the nose around with more rudder (skid) which never ends good

[carusoam]

Nice details shared gents!

 

Old Pilot, Are you knocking the rust off of your latent PPL???  After a 20year hiatus???

Sounds like fun times ahead!

Or I just missed some important detail….

Best regards,

-a-

[midlifeflyer]

14 hours ago, ilovecornfields said:

Winds are stronger now than back when you were flying. And YouTube has mostly replaced CFIs.

You can definitely tell that by the radio calls. I never heard junk like "last call"* or "position checks" until YouTube. 
 

(*If things are not to busy, I respond with, "two bud lights.")

[Hank]

9 minutes ago, midlifeflyer said:

You can definitely tell that by the radio calls. I never heard junk like "last call"* or "position checks" until YouTube. 
 

(*If things are not to busy, I respond with, "two bud lights.")

I always request something when I hear "last call," which has inky been in the last couple of years. 

Stupid stuff proliferate when instructors are the least experienced people around other than their primary students . . . .

[midlifeflyer]

10 minutes ago, Hank said:

I always request something when I hear "last call," which has inky been in the last couple of years. 

Stupid stuff proliferate when instructors are the least experienced people around other than their primary students . . . .

I may have been checked out by young instructors in more places more than most. I don't blame them for pilots picking up "influencer" jargon. 

[mike_elliott]

14 hours ago, Jerry 5TJ said:

When I was a kid most cars had tail fins, so perhaps the winds were stronger then, not now?   

Climate change, not needed now, just like it is making it easier to hit homers in the big leagues.  

 

[Pinecone]

16 hours ago, Shadrach said:

Stalling in a skid is far more dramatic than stalling in a slip.

This is a key point.  It not only about being uncoordinated, but in which direction.

If you are slipping to loose altitude and you start to stall, the high wing goes down.  Release the rudder, you are near level, fly away.

The killer is skidding the final turn.  Holding the low wing with ailerons, but trying to increase turn rate with rudder.  You start to stall, the low wing tucks under and boom, you hit the ground.

Find an instructor that knows what they are going and a spinnable (preferably aerobatic) and do some cross controlled stalls.  Slipping stalls are easier than straight ahead.  Skidding stalls WILL get your attention.

[Pinecone]

6 minutes ago, mike_elliott said:

Climate change, not needed now, just like it is making it easier to hit homers in the big leagues.  

 

It is easier, because the made the new ball parks a bit smaller.

[mike_elliott]

C'mon man! thats not the narrative! Climate change didnt affect the minor league HR % tho. Selective isnt it? 

Back on topic, stay out of rapid climate change when flying and you just may live.

[Old Pilot]

9 hours ago, carusoam said:

Nice details shared gents!

 

Old Pilot, Are you knocking the rust off of your latent PPL???  After a 20year hiatus???

Sounds like fun times ahead!

I have to pass a medical first. I'm 80 now but in pretty good shape. We will see.

 

Best regards,

-a-

 

[MikeOH]

I wonder how the new RHV policy of “pilot deviation” for overshooting final is going affect the base-final stall-spin accident rate. Especially if it gets adopted at other airports.

[ilovecornfields]

4 hours ago, Hank said:

Stupid stuff proliferate when instructors are the least experienced people around other than their primary students . . . .

Yes!!!!

[RLCarter]

2 hours ago, MikeOH said:

I wonder how the new RHV policy of “pilot deviation” for overshooting final is going affect the base-final stall-spin accident rate. Especially if it gets adopted at other airports.

What and who’s policy?

[MikeOH]

48 minutes ago, RLCarter said:

What and who’s policy?

From the FAA safety notice NOT2929 Air Traffic Operations Reid Hillview Tower Controlled Airport:(https://faasafety.gov/SPANS/noticeView.aspx?nid=12929

To be transparent it is specifically directed to CFIs but the salient quote seems draconian and I wonder if it would also be applicable to other pilots:

Regardless of where you are on the approach, if you are misaligned with the assigned runway you will be instructed to go-around. 

• If inside one mile and you stray from the extended runway centerline air traffic must file a mandatory operating report or if inside half-a-mile it will be treated as a pilot deviation with the accompanying records forwarded to the FSDO

[ilovecornfields]

26 minutes ago, MikeOH said:

From the FAA safety notice NOT2929.  To be transparent it is specifically directed to CFIs but the salient quote seems draconian and I wonder if it would also be applicable to other pilots:

Regardless of where you are on the approach, if you are misaligned with the assigned runway you will be instructed to go-around. 

• If inside one mile and you stray from the extended runway centerline air traffic must file a mandatory operating report or if inside half-a-mile it will be treated as a pilot deviation with the accompanying records forwarded to the FSDO

How far off the centerline to you have to be to get violated? An inch? A mile?