Crosswind

[midlifeflyer]

Mooney newbie:

 

I was surprised to see the relatively low (11 kt) max demonstrated crosswind component in the M20J.  I know it's not a limitation so I'm wondering what kind of crosswinds experienced members of this group have handled on a regular basis. Trying to get a handle on the "real" comfortable crosswind handling capability of the airplane. 

 

Thanks.

[M016576]

That's a direct crosswind component. It's not all that low... Even high powered jets with fly by wire systems struggle a bit at a 20-30 knot direct crosswind. At 22-23kt direct crosswind the rudder is pretty much maxed out after kicking out the slip. Any more feels like you'll collapse a gear (to me) due to side loading. That's all just my opinion.

[Marauder]

Mooney newbie: I was surprised to see the relatively low (11 kt) max demonstrated crosswind component in the M20J. I know it's not a limitation so I'm wondering what kind of crosswinds experienced members of this group have handled on a regular basis. Trying to get a handle on the "real" comfortable crosswind handling capability of the airplane. Thanks.

I remember speaking to Bill Wheat (Mooney test pilot) about the "demonstrated crosswind component" and how it was determined. Basically, it was the calculated crosswind the day the test was done. Nothing more. I have flown my F on a direct 90 degree 25 knot crosswind (sustained). I was starting to lose rudder authority and had to angle off the runway heading a few degrees to offset this. My guess is the crosswind capability for my plane is in the 22 to 24 knot range. I should also point out it is not an operation limitation. The criteria for crosswind from the FAA i believe states something along the lines an "average" pilot can handle. I suspect some manufacturers set it lower due to concerns over the definition of "average"

[gregwatts]

"Comfortable" will be determined by the pilot flying.....not the airplane. I would have no reservations with a 20-25 kt crosswind........you just have to be well prepared for a "what if" and in front of the airplane. My suggestion would be to whenever possible......practice crosswind landings to maintain proficiency and confidence.

[duke]

I agree with marauder. On my F I always figured about 20 knts max. J should be about the same. Take your bird to and do some practice approaches on a runway with a good xwind. you don't have to land. When you run out of rudder you have reached the planes max, which is usually more than my comfort zone>

[sleepingsquirrel]

Is it just me or have others experienced this? I am far more comfortable landing in cross winds that I would not take off in given a choice , and usually I'll fire up the 150 for those days.

[aviatoreb]

"Comfortable" will be determined by the pilot flying.....not the airplane. I would have no reservations with a 20-25 kt crosswind........you just have to be well prepared for a "what if" and in front of the airplane. My suggestion would be to whenever possible......practice crosswind landings to maintain proficiency and confidence.

 

When you - and others - say 20-25kts cross wind as the component orthogonal the runway?

[co2bruce]

I had to look that word up, I'm so embarrassed. 20kt wind at 90deg is more than i would feel confident in!

[aviatoreb]

I had to look that word up, I'm so embarrassed. 20kt wind at 90deg is more than i would feel confident in!

 

Sorry about that.  I'm a math prof and I said orthogonal without thinking, I should said 90.  Synonyms: 90deg=pi/2rad=orthogonal=perpendicular.  In vector speak - there is the phrase "orthogonal component" which says how much of your vector (the wind) is 90deg to the vector of interest (the runway).

 

But that said, I think pilots do tend to forget, (not picking on you at all - just standing on the soap box generally) the major difference between a wind of x-knots with some component orthogonal the runway, and z-knots orthogonal the runway.  Playing though with this -   50knots 30 deg off the runway is 25knots orthogonal.   50knots 60 deg off the runway is 43knots orthogonal component, but just 25knots 60deg off the runway is ~21 the runway.

 

For me, the ugliest days are when it is gusty and the direction is variable because it is impossible to make a really stabilized approach and all you can do is react and dance on your pedals.

[1964-M20E]

Just make sure it is a jitterbug and not waltz :-)

[The-sky-captain]

Is it just me or have others experienced this? I am far more comfortable landing in cross winds that I would not take off in given a choice , and usually I'll fire up the 150 for those days.

I generally feel the same way. I think the reason is that at the end of a flight I'm more comfortable that the engine and airframe are not going to give me any low altitude surprises.

[Marauder]

Is it just me or have others experienced this? I am far more comfortable landing in cross winds that I would not take off in given a choice , and usually I'll fire up the 150 for those days.

What you are experiencing is normal. When you are taking off with a crosswind, especially one that is gusty, it is a different sensation than when there are light winds or a headwind. The sensation of a crosswind, especially one with gusts, will require you to keep the ailerons adjusted correctly to compensate while making sure you hit the correct rotate speed. What I find that works is keeping the plane on the runway longer. If you begin to gain lift in a cross wind, the plane will want to both rotate into the wind and drift even though you are still on your wheels. It just doesn't feel right. What I try to do is keep the plane on the runway until I get that wheel barrow feel and then cleanly and briskly lift off.

[midlifeflyer]

That's a direct crosswind component. It's not all that low... .

Of course it's a direct crosswind component.

 

I said "relatively" low.  Generally, Cessna singles are 15, Pipers 17;  Bonanzas 17 and I've flown in stronger crosswinds than that in all of them. 

[midlifeflyer]

I remember speaking to Bill Wheat (Mooney test pilot) about the "demonstrated crosswind component" and how it was determined. Basically, it was the calculated crosswind the day the test was done. Nothing more. I have flown my F on a direct 90 degree 25 knot crosswind (sustained). I was starting to lose rudder authority and had to angle off the runway heading a few degrees to offset this. My guess is the crosswind capability for my plane is in the 22 to 24 knot range. I should also point out it is not an operation limitation. The criteria for crosswind from the FAA i believe states something along the lines an "average" pilot can handle. I suspect some manufacturers set it lower due to concerns over the definition of "average"

I've always suspected that the demonstrated crosswind component was a balance between marketing and safety concerns. The manufacturer chooses what it wants to publish and finds the day that fits the bill. 

 

Thanks for the info on what you've experienced. Makes me feel more comfortable about the airplane.

[carusoam]

'65 and earlier M20s will run out of rudder sooner than later model machines. The rudder was lengthened in 66.

So much of the plane's capability, especially in this case, is relying on pilot skill, training and currency.

It is near impossible for the manufacturer to write that anywhere.

YMMV...

-a-

[Jerry 5TJ]

'65 and earlier M20s will run out of rudder sooner than later model machines. The rudder was lengthened in 66.

So much of the plane's capability, especially in this case, is relying on pilot skill, training and currency.

 

I can confirm that the crosswind limits for the 1965 M20C are under 35 knots, at least for my skills. 

Fortunately the runway was 300 feet wide (and 11,000 useless feet long) where I tried landing with a 35 knot direct crosswind.

I should have landed orthogonal to the centerline.

[midlifeflyer]

I can confirm that the crosswind limits for the 1965 M20C are under 35 knots, at least for my skills. 

Fortunately the runway was 300 feet wide (and 11,000 useless feet long) where I tried landing with a 35 knot direct crosswind.

I should have landed orthogonal to the centerline.

With 35 kts and 300', you might have been able to land perpendicular to the centerline 

[Alan Fox]

Is it just me or have others experienced this? I am far more comfortable landing in cross winds that I would not take off in given a choice , and usually I'll fire up the 150 for those days.

An M20B has approx 4 degrees less rudder deflection than the later model model mooneys......If you change the rudder bellcrank in the tail , you will get substantially more rudder travel , it makes a difference......A used one in a yard is probably about 50 dollars , just a pain in the ass to change.....

[Awful_Charlie]

I've always suspected that the demonstrated crosswind component was a balance between marketing and safety concerns. The manufacturer chooses what it wants to publish and finds the day that fits the bill. 

 

Thanks for the info on what you've experienced. Makes me feel more comfortable about the airplane.

 

For FAA certification, an fixed proportion of the stalling speed as a crosswind has to be demonstrated.  So when the manufacturer gets that far, it is only for marketing or the hell of it that they would go and do more.  That is why for our Mooneys, they had to demonstrate it could cope with 13kts, but as they weren't on the stops to do this, they could put it in the POH as 'not a limit'

AC 23-8B (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/469CD77D24955F4E86256DA60060C156?OpenDocument)

107. SECTION 23.233 DIRECTIONAL STABILITY AND CONTROL.

a. Explanation.

(1) Crosswind. This regulation establishes the minimum value of crosswind that must be demonstrated. Since the minimum required value may be far less than the actual capability of the airplane, higher values may be tested at the option of the applicant. The highest 90- degree crosswind component tested satisfactorily should be put in the AFM as performance information. If a demonstrated crosswind is found limiting, it has to be introduced in Section 2 of the AFM.

b. Procedures.

(1) Crosswind.

(a) The airplane should be operated throughout its approved loading envelope at gradually increasing values of crosswind component until a crosswind equivalent to 0.2 VSO is reached. All approved takeoff and landing configurations should be evaluated. Higher crosswind values may be evaluated at the discretion of the test pilot for AFM inclusion.

[sleepingsquirrel]

An M20B has approx 4 degrees less rudder deflection than the later model model mooneys......If you change the rudder bellcrank in the tail , you will get substantially more rudder travel , it makes a difference......A used one in a yard is probably about 50 dollars , just a pain in the ass to change.....

So, now it's time for me to upgrade to a long body. Just wait till  I tell my wife.

[jetdriven]

That's a direct crosswind component. It's not all that low... Even high powered jets with fly by wire systems struggle a bit at a 20-30 knot direct crosswind. At 22-23kt direct crosswind the rudder is pretty much maxed out after kicking out the slip. Any more feels like you'll collapse a gear (to me) due to side loading. That's all just my opinion.

The 747-200 and -400 are certified to land in a 30 knots crosswind, and it can even autoland on two autopilots (out of three) and/or with three engines like that.

[M016576]

<blockquote class='ipsBlockquote'data-author="jetdriven" data-cid="88976" data-time="1359930755"><p>

The 747-200 and -400 are certified to land in a 30 knots crosswind, and it can even autoland on two autopilots (out of three) and/or with three engines like that.</p></blockquote>

I've seen the video of the 747 landing at Hong Kong in a strong crosswind: awesome stuff. The F-15 and F-18 are good up to 30 kts as well, but you do a serious number on their tires, and the roll out is fairly uncomfortable any time you're over about 20 kts of direct crosswind. They are capable, but it's not as easy as the winds right down the runway. No real auto pilot on the F-15 (it's got a baro alt hold, and an attitude hold, but they are unreliable at best). The F-18 has an OK autopilot, but it won't land for you or fly a certified approach for you (unless you're at the carrier). All hand flying in crosswinds in those jets (crab to kick out!).

[aviatoreb]

<blockquote class='ipsBlockquote'data-author="jetdriven" data-cid="88976" data-time="1359930755"><p>

The 747-200 and -400 are certified to land in a 30 knots crosswind, and it can even autoland on two autopilots (out of three) and/or with three engines like that.</p></blockquote>

I've seen the video of the 747 landing at Hong Kong in a strong crosswind: awesome stuff. The F-15 and F-18 are good up to 30 kts as well, but you do a serious number on their tires, and the roll out is fairly uncomfortable any time you're over about 20 kts of direct crosswind. They are capable, but it's not as easy as the winds right down the runway. No real auto pilot on the F-15 (it's got a baro alt hold, and an attitude hold, but they are unreliable at best). The F-18 has an OK autopilot, but it won't land for you or fly a certified approach for you (unless you're at the carrier). All hand flying in crosswinds in those jets (crab to kick out!).

 

Hi M01656.  I bet you are pretty familiar with the F15 by now. I was thinking about you three weeks ago when I was at the air national guard picking up a friend who is an f16 pilot for them and he needed a ride home.  When he texted and asked for a ride, I jumped, because I got to walk around the f16's up close and kick tires.

 

Now fast airplanes stalling airplanes like a 747, and I am guessing a f15, 16, 18 are all even faster stalling than even a 747, and this makes them different from our mooneys in a fundamental way as to how 30knots orthogonal feels.  I do not know what any of these jets stall at so I have to make up numbers - though I did find 160ias for short final for the f16 on the internet, but who knows if that number is actually correct.  But lets just go with that number for sake of argument.  If you can tell us what is the stall speed of one of your f15 or 18s I would be most interested out of curiosity but I understand if you are not allowed.

 

The difference of ratios of how a cross wind feels at a slow speed as compared to a fast speed is a matter of understanding similar triangles - elementary Euclidean geometry.  Vector components are proportional.  When you are on short final in an f16 lets take 160ias as 1.3 Vso which makes 160/1.3=123 stall speed which is ROUGHLY double a modern M20J,k,and on up.  So 15knots orthogonal when traveling 61.5kts is like 30knots when traveling at 123knots as they both will create roughly the same crab angle.

[sleepingsquirrel]

This speed difference may explain why I feel more in control landing than taking off. Its always coming up to takeoff speed that I feel the most lack of control and possibility of side loading.

[midlifeflyer]

This speed difference may explain why I feel more in control landing than taking off. Its always coming up to takeoff speed that I feel the most lack of control and possibility of side loading.

That's one of the reasons for the crosswind takeoff technique of keeping the airplane on the ground (with proper deflection) until there is enough airspeed for a "brisk" departure from the ground.