M20J Demonstrated Crosswind

[Shadrach]

27 minutes ago, PT20J said:

It’s because the airplane sits on the ground at a positive angle of attack, so it’s light on the gear at landing speed. The flaps increase the effective angle of attack and exacerbate the effect. That’s why a lot of us raise the flaps after touchdown.

 

This is an interesting thought exercise. Your statement is indeed true because deploying the flaps increase the effective angle of incidence, which in turn does increase AOA on the ground, if not in the air.  I surmise that the instant changes in pitch when deploying flaps in the air are the wing seeking the same (or nearly the same) AOA as the trailing edge of the deployed flaps changes the effective wing chord.  A unique aspect of flying a Mooney with hydraulic flaps is the very precise correlation of flap handle movement to nose down pitch.  The feel is so closely correlated that It almost feels like you’re using a hydraulic jack to raise the tail.

[Bartman]

Earlier this month on 4/11/24 we landed rwy 32 at KDTS with winds directly out of the West at 23kts and gusting to 33 and horrible wind shear at about 100 feet.  It was so bad the lady running the tower called the winds 3 times from the time we crossed the shoreline to the time we crossed the threshold.  It was by far the most crab I have ever seen on final, and I aimed for the far left side of the runway.  

I am sure others have done and seen much more, but I now have a much greater appreciation for the crosswind capabilities of the M20J.

[Hank]

26 minutes ago, Bartman said:

Earlier this month on 4/11/24 we landed rwy 32 at KDTS with winds directly out of the West at 23kts and gusting to 33 and horrible wind shear at about 100 feet.  It was so bad the lady running the tower called the winds 3 times from the time we crossed the shoreline to the time we crossed the threshold.  It was by far the most crab I have ever seen on final, and I aimed for the far left side of the runway.  

I am sure others have done and seen much more, but I now have a much greater appreciation for the crosswind capabilities of the M20J.

Winds at the ground weren't bad, takeoff and landings were good. But Sunday from central AL to central NC and back, I had 20-25° wind correction in cruise for almost 3 hours each way--up at 7500, back between 3000-4500.

I remember one short flight where I looked out the passenger side window to see where we were going, but to keep a minimum 20° wind correction angle for 3 hours over 4 states was just surprising. Smooth but surprising . . . .

[M20F-1968]

Consider gear down, full flaps, plus speed brakes.  This very dirty configuration allows you to carry more power for the same airspeed you would use without the speed brakes.  The plane feels heavier, does not get pushed around as much.  I have completed some of my best landings with this configuration.  My plane will climb on a go-around with this configuration, although it is more sluggish.  Add full power, keep nose down as appropriate, stow speed brakes, stow gear, and lastly raise flaps.  This was taught to me by a high time Ovation/Acclaim pilot who uses this configuration regularly.  I just resort to it when I have a strong crosswind or need to slow down.  Do not apply the speed brakes close to the ground.  Fly the approach with them if you are going to use them.  Although, I did apply them once late in the approach with a strong 25ish knot crosswind (applied perhaps at 500 ft) and landing was fine.  It would not do that routinely.

John Breda

[jaylw314]

On 4/28/2024 at 12:24 PM, SOLER said:

...

Remember, of the three primary control surfaces, the most effective is the rudder, followed by elevator(s), then ailerons.  So you might have enough rudder to align the nose, and you might still have enough aileron to kill the drift, but do you have enough ground clearance on the upwind wingtip?  

Aside from the fact that this competes for one of the longer necro posts I've seen in a while, I don't understand what you mean by "most effective is the rudder."  If anything, it is the least effective attitude control.

In one of Barry Schiff's "The Proficient Pilot" articles (I don't know the issue, but it's in the 1980 compilation book of the same name), he suggests a modified version of the "kickout" for crosswind landings.  Rather than the wings-level kickout that airliners use, he proposed a crabbed approch with a dynamic sideslip entry just before touchdown, low enough so the upwind wheel touching down interrupts the slip, and claims he landed a Cherokee 140 in 35 knot crosswinds at KSMO.

While I've never attempted this IRL, I have tried it in flight sims.  One point he does not mention is that the dynamic entry seems to allow for more crosswind compensation than you would normally have the rudder authority for.  So while the M20J seems to run out of rudder authority for a sustained sideslip around 15-20 knots of crosswind at typical approach speeds, a dynamic entry will swing your nose around even further than that, at least for a couple seconds, during which you hopefully touch down.

It's worth a read if you can find it.

Edited May 9 by jaylw314

[Shadrach]

16 minutes ago, jaylw314 said:

A crabbed approch with a dynamic sideslip entry just before touchdown, low enough so the upwind wheel touching down interrupts the slip.

This is a more detailed description of the technique I mentioned earlier.  I’ve never read Barry’s piece, but I think a lot of pilots stumble into this method with time.

[jaylw314]

3 hours ago, Shadrach said:

This is a more detailed description of the technique I mentioned earlier.  I’ve never read Barry’s piece, but I think a lot of pilots stumble into this method with time.

Have you ever used it to overcome insufficient rudder authority?  I've never had the opportunity or bravery to attempt that 

As I said, it's worth a read if you can find it

Edited May 9 by jaylw314

[PeteMc]

1 hour ago, jaylw314 said:

Have you ever used it to overcome insufficient rudder authority? 

I think you then fall into the category of those that will agger one in...  Everything would have to be EXACTLY right for you not to be in a situation where you can't keep the nose straight down the runway if you really don't have rudder authority.  

I have no problem trying most any runway if the wind cross angle or the velocity are not crazy.  But it's not about the numbers, it is all about giving it a try to see if I still can easily make the plane go where I want it to.  If you're going to hope you slip it down onto the wheels because you really don't have actual FULL control of the plane to make that happen, I see it as an accident waiting to happen.  One good short gust to lift you up and then just as quickly going away will be real interesting.  Just my opinion...  

 

[Shadrach]

8 hours ago, jaylw314 said:

Have you ever used it to overcome insufficient rudder authority?  I've never had the opportunity or bravery to attempt that 

As I said, it's worth a read if you can find it

Sort of, but I did not really intellectualize it in that way. Years ago on a particularly windy/gusty day when winds were favoring 27, I asked tower if I could have 20. I don’t recall the exact numbers, but they were stupid…something like 280 27G38 (I’ll check my logs). I don’t recall if I ran out of rudder or just became uncomfortable with the varying bank angle needed to track the runway.  
I elected to transition from a slip to a crab, which was fairly extreme, but more comfortable than having to stand on the Rutter while varying bank angle. I wish I could say that I transitioned from the crab into the perfect amount of slip for the flare. It was more of an align the nose with the runway and do whatever seemed necessary to facilitate an expeditious touchdown.  Donk, donk, donk. Right main, nose, then left main. I wheelbarrowed slightly in my efforts to get the thing planted. Flaps up. Then a gust blew us into a skid. Awful sound of tire screeching and gear chattering under side load. I did not bend anything, but I would never intentionally land in conditions like that again. I’m a late bloomer in some ways. I was in my early 30s when I did this. I started flying plenty early enough to have gotten something this stupid out of the way in my 20s.

 

 

 

[PT20J]

If you want to be absolutely certain you can land with a particular crosswind, set up a forward slip early. If you cannot hold the airplane on the extended centerline with the nose aligned with the runway, the wind is too strong.

It is, of course, possible to land in higher crosswinds. This is because the wind speed is much lower close to the runway due to ground friction. So, you can crab down close to the runway and convert to forward slip when very close to the ground. But this takes more skill because you don't have a lot of time to get it set up and you want to touch down on the upwind wheel, nose high, pointed straight and with no sideways drift.

[Vance Harral]

1 hour ago, PT20J said:

If you want to be absolutely certain you can land with a particular crosswind, set up a forward slip early.

This is entirely reasonable advice.  But "early" is subjective, and as you note, wind at the surface is often lower than wind at altitude - even 100' AGL can make a significant difference.  I don't necessarily want to encourage pilots to wait until the landing flare to establish a crosswind slip.  But I've also coached a few pilots on the more timid side, that inability to hold the extended centerline in a slip when they're hundreds of feet above and a half mile from the runway threshhold isn't particularly meaningful, and they might be giving up on things a little early.

The reasonable abort altitude varies with skill and experience, of course.  I think it's a good exercise to go up to a safe altitude and practice getting into and out of slips until one's comfort with doing so increases.  The purpose of this isn't necessarily just for crosswind landings.  Smoothly adding and removing slip on approach is also a nice drag management technique for precision landings, particularly in simpler airplanes with fewer drag configuration options.