Right rudder?

[PT20J]

According to Bob Kromer, Mooney sets the demonstrated crosswind low due to concern that "average pilot technique" will be strained by greater crosswinds due to the airplane's tendency to float in ground effect if speed is a little high at flare. Bob's personal limit was 18 kts, but that was when he was flying every day and very proficient.

Keep in mind that crosswinds are frequently gusty and may be turbulent due to airflow over obstructions along the sides of the runway. Gustiness and turbulence require somewhat higher speeds and that exacerbates the floating problem. In my experience, when landing with a strong crosswind with gusts or turbulence, you need to really "work" the flare with pitch AND power to prevent the plane from touching down until it is nose high and straight with no side drift. That requires a certain amount of patience, and some touchdowns may still not be pretty.

Under FAR Part 25, even transport category airplanes do not have to show a crosswind capability greater than 25 kts.

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[MB65E]

That’s understandable as I’ve seen about 5 wing tip scrapes of lower skins on m20’s. My left wing tip I noticed some scuffed skin at the tip that was painted over in the 90’s. 

-Matt

[jaylw314]

On ‎8‎/‎26‎/‎2019 at 6:29 AM, bradp said:

Wonder how much of the crosswind component in the POH is influenced by the lawyers...we all know that the med and long bodies with full rudders can do 30+ direct but that would never show up in a POH.  

I can buy the idea that test pilots would only use normal techniques to get max demonstrated crosswind.  That means side slipping to landing while coming in at 70'ish KIAS.

I think I run out of rudder when the crosswind get up to about 15 knots that way.  You can do more by landing faster or using a different technique, but I don't think that's the idea of max demonstrated crosswind...

[bradp]

Forward slip with takeoff flaps and a bit more speed Can do > 25across the runway without leaving centerline.  Maybe that doesn’t count as “normal technique” then.   

[Ragsf15e]

5 hours ago, bradp said:

Forward slip with takeoff flaps and a bit more speed Can do > 25across the runway without leaving centerline.  Maybe that doesn’t count as “normal technique” then.   

I respect your opinion but disagree.  25kts is a significant amount of x wind.  If you’ve got 25 knots at a 45 degree angle, you’re looking at about 15 knots crosswind component and that’s probably right at the rudder limit.

The extra speed helps on final and gives you more rudder/aileron authority, but you still have to slow down to land.  Now you might not flare it out to a full stall and roll it on, but you’ve got to slow enough to get a safe landing attitude.  At that slower speed, you’ll start to drift laterally.  It will be tough to see, but the gear will feel it!

Edited August 28, 2019 by Ragsf15e

[jaylw314]

8 minutes ago, Ragsf15e said:

I respect your opinion but disagree.  25kts is a significant amount of x wind.  If you’ve got 25 knots at a 45 degree angle, you’re looking at about 20 knots crosswind component and that’s probably still past the rudder limit.

The extra speed helps on final and gives you more rudder/aileron authority, but you still have to slow down to land.  Now you might not flare it out to a full stall and roll it on, but you’ve got to slow enough to get a safe landing attitude.  At that slower speed, you’ll start to drift laterally.  It will be tough to see, but the gear will feel it!

Remember though, that there is a boundary layer near the ground that reduces wind speed as you decrease height, which ideally reduces to zero at the ground.  So the 25 knot x-wind at the weather station 15 feet off the ground may be significantly less 5-6 feet off the ground.  Coming in fast lets you maintain directional control on approach, then you can start slowing down within the boundary layer and still maintain directional control.  If you balloon up, though, you will be exposed to stronger winds, though.

[Ragsf15e]

1 minute ago, jaylw314 said:

Remember though, that there is a boundary layer near the ground that reduces wind speed as you decrease height, which ideally reduces to zero at the ground.  So the 25 knot x-wind at the weather station 15 feet off the ground may be significantly less 5-6 feet off the ground.  Coming in fast lets you maintain directional control on approach, then you can start slowing down within the boundary layer and still maintain directional control.  If you balloon up, though, you will be exposed to stronger winds, though.

I don’t disagree with that at all.  But it would be misleading to say it can land in a 25 knot crosswind, except that 25 knots has to be at 25’ above the ground and it’s only 15 knots at 3’ up.

[M00N37]

Landing in steady crosswind is easy. I try to kick the rudder and align the plane with runway right before touch down. Need to come in at the right speed so it wouldn’t float. Just like what I did in jets. 

Gusty wind crosswind is another story.