Landing flaps cross post

[Tip]

https://www.facebook.com/Boldmethod/posts/10155143851009035

[Buckaroo]

https://www.facebook.com/Boldmethod/posts/10155143851009035

That's a good read and makes sense! I especially agree that a faster clean approach lessens pitch angle changes making the contact with the runway firmer and flatter.

 

This is what I envisioned but couldn't articulate.

[Ed Cesnalis]

I agree faster approaches reduce pitch changes.  Contact with the runway has to be soft however not firm, my CTSW doesn't have anything to absorb the shock and the gear struts will bend if firmness of contact isn't well controlled beyond what most GA aircraft have to be.

 

And of course minimizing pitch changes and having a firm contact still leaves the most vulnerable speed range later in the landing sequence when you have wheels on the ground.

 

My concern about being vulnerable on rollout remains elevated because I fly a light sport that is more susceptible to being gusted beyond control authority on rollout.

[WmInce]

https://www.facebook.com/Boldmethod/posts/10155143851009035

I love Boldmethod. Those guys do a great job.

I make it a regular habit to scour each issue I receive via email.

Good stuff. A great way to continue staying fresh on some things.

[Doug G.]

I love Boldmethod. Those guys do a great job.

I make it a regular habit to scour each issue I receive via email.

Good stuff. A great way to continue staying fresh on some things.

I repost them and Pilotworkshops to our EAA Facebook site. Good stuff.

[Buckaroo]

I repost them and Pilotworkshops to our EAA Facebook site. Good stuff.

Doug I just joined EAA about two weeks ago. I haven't received any info or correspondence from them. As a member what resources can I now enjoy?

[Buckaroo]

I agree faster approaches reduce pitch changes. Contact with the runway has to be soft however not firm, my CTSW doesn't have anything to absorb the shock and the gear struts will bend if firmness of contact isn't well controlled beyond what most GA aircraft have to be.

 

And of course minimizing pitch changes and having a firm contact still leaves the most vulnerable speed range later in the landing sequence when you have wheels on the ground.

 

My concern about being vulnerable on rollout remains elevated because I fly a light sport that is more susceptible to being gusted beyond control authority on rollout.

Pitch changes are not the only pilot adjustments during the touchdown in windy conditions with full flaps. Another dynamic that is more intense due to full flap cross wind landings are lateral forces. Picture in a crab the forces pushing against the flaps! The side loads with say a 45 degree cross wind would tend to increase the crab making crab transitions to a slide slip more dramatic.

 

All in all a pilot is going to be a very busy airman landing cross winds with full flaps versus no flaps!

 

If the above statement is agreeable to most it can be said that full flap landings with stout winds are more dangerous!

[Ed Cesnalis]

Pitch changes are not the only pilot adjustments during the touchdown in windy conditions with full flaps. Another dynamic that is more intense due to full flap cross wind landings are lateral forces. Picture in a crab the forces pushing against the flaps! The side loads with say a 45 degree cross wind would tend to increase the crab making crab transitions to a slide slip more dramatic.

 

All in all a pilot is going to be a very busy airman landing cross winds with full flaps versus no flaps!

 

If the above statement is agreeable to most it can be said that full flap landings with stout winds are more dangerous!

 

Your premise is wrong.  There are no lateral forces pushing against the flaps in a crab. Crabbing prevents any such forces because when you crab you choose to fly with your nose in the relative wind.

 

Non existent side-loads do not increase crab angles, crab angle (with no slip) is determined solely by crosswind angle x speeds (wind and aircraft) and is same with or without flaps/flaperons. 

 

'Agreeable to most' is how fast landings have become the norm but consensus can be wrong as in this case.

 

To restate you argument you could say that approaching fast will minimize crab angle and minimize the resulting correction into a side slip.  The problem with this thinking is that you could just enter the side slip early in the approach and avoid the crab/correction entirely and you do not have to increase speed/risk and decrease flaps to do that.

[Buckaroo]

Your premise is wrong. There are no lateral forces pushing against the flaps in a crab. Crabbing prevents any such forces because when you crab you choose to fly with your nose in the relative wind.

 

Non existent side-loads do not increase crab angles, crab angle (with no slip) is determined solely by crosswind angle x speeds (wind and aircraft) and is same with or without flaps/flaperons.

 

'Agreeable to most' is how fast landings have become the norm but consensus can be wrong as in this case.

 

To restate you argument you could say that approaching fast will minimize crab angle and minimize the resulting correction into a side slip. The problem with this thinking is that you could just enter the side slip early in the approach and avoid the crab/correction entirely and you do not have to increase speed/risk and decrease flaps to do that.

Using your last paragraph does simplify the argument! You and I are both on 1 mile finals on two parallel runways with 16 knot direct crosswinds. I'm going in clean and you ultimately going to use 40 degrees of flaps. We both crab to short final and then set up our flap settings. My selection is zero flaps 65 knots over the numbers somewhat flat pitched upwind wing low and rudder as needed. Once smoothly set on the runway my weight will quickly transition to the runway but a go around will be quick if needed. Because of more speed and probably carrying power my rudder will be more effective than a slower full flap setting.

 

You will kick out the crab at a much lower speed and be cross controlled to do it. (Scary) then with lower speeds and more lift you will be more vulnerable to gusts sheers etc. as your plane touches a lot lighter than mine cross skidding is more possible. You rush to lift the flaps. (Busy) your rudder will be sluggish compared to the faster aircraft.

 

A incident with the slower aircraft is more possible in my opinion. The slower aircraft will crash a few knots slower and this is good.

 

The faster cleaner plane will be the one that the chances of soiling ones pants will be less often!????????

[Ed Cesnalis]

Thanks for the thoughtful response. I very much like that you provide basis for your thinking.  

 

However:

 

• You make my scenario 'Scary' by forcing me into a crab to sideslip transition when I don't do that, generally.  I turn final or establish on final with a sideslip and maintain my alignment and heading throughout my approach.
• You continue to argue that fast is better because of authority when you are still fast. Everything you said is true in fact your comparison emphasizes the fact that my vulnerable speed happens earlier than yours. At touchdown you are still 30% above stall with crisper responses while I am at minimum speed for conditions and have to travel my controls farther for the same response.
• You argue that my CT's controls are more sluggish (at touchdown) but you fail to address that your CT will become just as sluggish as mine later in your rollout. The difference is when you get gusted and the CTSW wants to skip skideways due to your slow speed you will have 3 wheels on the ground and likely brakes applied where at that same speed I will have a single wheel on the ground and even though slow I am still prepared for the untimely gust, 1 wheel works fine for that 3 don't.
• Your comparison forces me into a configuration that I wouldn't use. When conditions are beyond the demonstrated crosswind component my flap selections would be 30 or 15 not 40.  Landing at minimum speed for conditions isn't the same as landing in calm buoyant air.

 

When wind sheer is in the landing environment you cannot get your CTSW on the runway all the way to a full stop without becoming vulnerable to sheer due to your aircraft producing lift while it isn't flying.  There is no landing speed or technique that can make this go away, you have to get slow at some point an go through a vulnerable range of speeds until you are slow enough.  This vulnerable range can even include zero speed if sheer produces gusts high enough, pilots have to call for wing walkers at some point.

 

You can always win the argument, in your own minds that touching down faster with less changes is easier and easier to fly away from, even easier after you are on the ground and still fast.  When you do this you miss the point that there is extra risk, some induced and some unavoidable.

[Buckaroo]

Thanks for the thoughtful response. I very much like that you provide basis for your thinking.

 

However:

 

• You make my scenario 'Scary' by forcing me into a crab to sideslip transition when I don't do that, generally. I turn final or establish on final with a sideslip and maintain my alignment and heading throughout my approach.
• You continue to argue that fast is better because of authority when you are still fast. Everything you said is true in fact your comparison emphasizes the fact that my vulnerable speed happens earlier than yours. At touchdown you are still 30% above stall with crisper responses while I am at minimum speed for conditions and have to travel my controls farther for the same response.
• You argue that my CT's controls are more sluggish (at touchdown) but you fail to address that your CT will become just as sluggish as mine later in your rollout. The difference is when you get gusted and the CTSW wants to skip skideways due to your slow speed you will have 3 wheels on the ground and likely brakes applied where at that same speed I will have a single wheel on the ground and even though slow I am still prepared for the untimely gust, 1 wheel works fine for that 3 don't.
• Your comparison forces me into a configuration that I wouldn't use. When conditions are beyond the demonstrated crosswind component my flap selections would be 30 or 15 not 40. Landing at minimum speed for conditions isn't the same as landing in calm buoyant air.

When wind sheer is in the landing environment you cannot get your CTSW on the runway all the way to a full stop without becoming vulnerable to sheer due to your aircraft producing lift while it isn't flying. There is no landing speed or technique that can make this go away, you have to get slow at some point an go through a vulnerable range of speeds until you are slow enough. This vulnerable range can even include zero speed if sheer produces gusts high enough, pilots have to call for wing walkers at some point.

 

You can always win the argument, in your own minds that touching down faster with less changes is easier and easier to fly away from, even easier after you are on the ground and still fast. When you do this you miss the point that there is extra risk, some induced and some unavoidable.

I agree that the actual touch down speed will be similar for both of us. I think what you're driving at are those things leading up to that touchdown event. You are concerned about needless risky speeds from non flap operation. Your opinion of slower and flapped approaches to landing are safer than faster and flatter non flap landings. Physics wise would prove a crash at less speed would result in less damage.

 

My point for all the things I already mentioned is that bad events due to stalls, loss of control, poor speed control, loss of control surface authority and unusual weather phenomenon traveling across the numbers in high crosswinds is lessened by clean flap settings and higher approach speeds. (Big sentence)

[Ed Cesnalis]

I don't think I ever said touch down speeds will be similar.  

 

You can approach and even get one wheel down while fast and then hold it from settling in order to get the fast approach to end up being minimum speed by the time you settle on 2 wheels. Thats a good compromise to me.

 

Mostly your still saying the same thing.  You too have to slow down even if your are fast over the numbers. You too can get gusted when you are at that vulnerable speed.

[FlyingMonkey]

The CTSW POH in Section 8.9 - Normal Landing says:

 

"Flaps:           As desired, 40° for short field"

 

So we can go around and around about which setting is best for some conditions, but the fact is that the manufacturer / designer is completely agnostic on the subject other than for short field operations, when full flaps are recommended.  That the POH doesn't otherwise specify a setting and leaves it to the pilot, to me indicates that there are probably pros and cons to each setting, and that no setting provides a compelling safety benefit over the others.

[Buckaroo]

The CTSW POH in Section 8.9 - Normal Landing says:

 

"Flaps: As desired, 40° for short field"

 

So we can go around and around about which setting is best for some conditions, but the fact is that the manufacturer / designer is completely agnostic on the subject other than for short field operations, when full flaps are recommended. That the POH doesn't otherwise specify a setting and leaves it to the pilot, to me indicates that there are probably pros and cons to each setting, and that no setting provides a compelling safety benefit over the others.

I'm always searching for new ideas and CT brings up some good stuff to consider! I'm still a airspeed is good kinda guy and still learning this aircraft. My prior habits while flying wind held true for years and got me home every time.

 

Great discussion CT and thanks flying monkey!

[ralarcon]

The CTSW POH in Section 8.9 - Normal Landing says:

 

"Flaps:           As desired, 40° for short field"

 

So we can go around and around about which setting is best for some conditions, but the fact is that the manufacturer / designer is completely agnostic on the subject other than for short field operations, when full flaps are recommended.  That the POH doesn't otherwise specify a setting and leaves it to the pilot, to me indicates that there are probably pros and cons to each setting, and that no setting provides a compelling safety benefit over the others.

Agree !    However, for me. the higher the crosswind  ,the easier it is to land the aircraft with lower flap angles (CTLS).

 

Cheers

[FlyingMonkey]

 

That means you guys must drive a Fiat.    Sorry I just couldn't resist. 

 

 

Hey, I drive a Fiat!  Or at least a car made by Fiat Chrysler of America (FCA):         

 

[Buckaroo]

Agree ! However, for me. the higher crosswind circumstances ,the easier it is to land the aircraft with lower flap angles (CTLS).

 

Cheers

I always wanted to land on carriers!????

[Buckaroo]

Hey, I drive a Fiat! Or at least a car made by Fiat Chrysler of America (FCA):

 

I like that Fiat!

[Roger Lee]

I knew there was something strange about you I just couldn't put my finger on it.

[Buckaroo]

I knew there was something strange about you I just couldn't put my finger on it.

We've only scratched the surface!????

[WmInce]

By far, the coolest muscle car I have ever rode in. At one point, I thought the front wheels were going to come off the ground.

What a nice ride!