Max Wind Speed For Your Aircraft?

johntlewis

New Member
Hello All:

I was just checking out the TAF for my area and we're supposed to have winds gusting up to 26 today. That got me to wondering what some of you guys consider the maximum safe wind speed for the type of aircraft you fly. I usually fly the C172 since I'm a CFI and I once flew in winds gusting to 32. It was a pretty stressful ride and I don't know if I would want to do that again.
 
I fly a C-150 and I won't take it out in more than about 20 knots of wind, but that's more a function of the airport and surrounding terrain where I'm at rather than the limits of the aircraft (we get turbulence and downdrafts off of nearby hills on windy days). When climb performance is only 300 or 400 fpm, hitting a 300 or 400 fpm downdraft during takeoff out of a short field can get kind of hairy.

I used to fly C-152s in the desert of eastern Washington and my limit was about 30 or 35 knots. I didn't mind flying in that much wind, it's the taxiing that gets me. The C-152 is so light, and has such a large surface area aft of the main gear, that it will really want to weathervane into the wind while taxiing. It takes a lot of differential braking and bursts of power to get it to go where you want it to.

I flew Piper Arrows a fair amount in Washington too, and never found a limit for them. As long as I could land into the wind, taxiing never seemed to be a problem, even in 30 knot winds.
 
I've landed the 737 in winds gusting to 56 knots. They were almost straight down the runway though. It's the crosswind and terrain/building induced turbulence in strong winds that is the concern. Also the condition and width of the runway would be part of the go/no-go decision in strong winds.

The 777 has a max demonstrated crosswind component of 40 knots on a dry runway. I've only done a little over 20 for real and it was easy enough.


Typhoonpilot
 
I've landed the 737 in winds gusting to 56 knots. They were almost straight down the runway though. It's the crosswind and terrain/building induced turbulence in strong winds that is the concern. Also the condition and width of the runway would be part of the go/no-go decision in strong winds.

The 777 has a max demonstrated crosswind component of 40 knots on a dry runway. I've only done a little over 20 for real and it was easy enough.


Typhoonpilot

The number sounds impressive, but it's not that the airplane is more capable than others. It's just that there happened to BE 40 kts crosswinds on the day they took the FAA out to demonstrate the crosswind capability.

The MD-11 has 36 kts, while the DC-10 had 31. No reason both couldn't be 40 or more, just what happened to be the conditions on the day that did the respective tests.
 
The number sounds impressive, but it's not that the airplane is more capable than others. It's just that there happened to BE 40 kts crosswinds on the day they took the FAA out to demonstrate the crosswind capability.

The MD-11 has 36 kts, while the DC-10 had 31. No reason both couldn't be 40 or more, just what happened to be the conditions on the day that did the respective tests.

Very true, that is why it is demonstrated crosswind component. We've all done crosswind landings in the simulator above the maximum demonstrated and they are possible.

As an interesting aside. That day in Pittsburgh with 56 knot winds I watched two A320s go-around as we taxied in. When we got to the terminal there were no Airbii at all to be seen. Seems they were having a problem with convincing the computer it was okay to land with such a low groundspeed. Apparently there is a way to get around that, but nobody was doing it.


Typhoonpilot
 
happened to BE 40 kts crosswinds on the day they took the FAA out to demonstrate the crosswind capability.


Interesting, though, that the crosswind that just happened to occur on testing day for jet transports is about twice what just happened to occur for GA aircraft.

I suspect there is some other decision-making process going on behind the scenes about what goes on the AFM.
 

As an interesting aside. That day in Pittsburgh with 56 knot winds I watched two A320s go-around as we taxied in. When we got to the terminal there were no Airbii at all to be seen. Seems they were having a problem with convincing the computer it was okay to land with such a low groundspeed. Apparently there is a way to get around that, but nobody was doing it.


Typhoonpilot

very interesting info... not sure, but what does ground speed have to do with landing? (as long as its not like 50 on a airbus I guess lol)
 
At the 141 school I taught at, we had an operations manual that dictated the maximum wind we would dispatch in for student pilots and for dual instruction. I can't remember the exact figures, but for dual it was some number between 30 and 40 knots and a gust factor of 20 I believe. For students going solo it was lower of course. You really need to set your own personal limitations, just like you do after getting your instrument rating.

Since we are also talking about larger aircraft on this thread, the CRJ has a max demonstrated crosswind component of 27 knots. Where I am, this number is only considered a limitation on a wet runway. For contaminated runways or for FO's with less than 100 hours we have a limit of 15 knots.

As you see, the theme is setting limitations based on yourself and conditions, not what the test pilot in the aircraft did.
 
Interesting, though, that the crosswind that just happened to occur on testing day for jet transports is about twice what just happened to occur for GA aircraft.

I suspect there is some other decision-making process going on behind the scenes about what goes on the AFM.

I think they can find winds better in a larger airplane. . . Taking a cessna from wichita to canada or hawaii for wind testing is a pretty dumb idea. .. . it's easier to stay in wichita and find a windy day, even though the crosswind component isn't that much...... You can take a 777 to austrailia or africa and search out higher winds/crosswinds and do some testing along the way....
 
I think they can find winds better in a larger airplane. . . Taking a cessna from wichita to canada or hawaii for wind testing is a pretty dumb idea. .. . it's easier to stay in wichita and find a windy day, even though the crosswind component isn't that much...... You can take a 777 to austrailia or africa and search out higher winds/crosswinds and do some testing along the way....

I guess that's my point. This appears to be more of a marketing issue. Saying "15 knots demonstrated" on a C172 is good enough to sell the airplane. Saying 30 knots demonstrated probably wouldn't sell any more and could seem to be encouraging inexperienced pilots to take the airplane into conditions the pilots weren't prepared for.

However, I suspect it'd be a handicap in selling a jet to provide a "12 knot demonstrated crosswind".
 
I've put 172's down with a 30 knot direct crosswind, though it wasn't gusting and I think the rudder had just about hit the stops at 30.

Heck I think I did that one with kellwolf actually...
 
EMB-135/145

Max tailwind - 10 knots
Max demonstrated X-wind - 30 knots

It's pretty common to experience conditions right at those maximums. It's no problem as long as you modify your control inputs accordingly, and check your landing distances for the tailwind.

I would prefer a 30 knot x-wind over a 10 knot tailwind. Much easier to land on the aiming points, and it's actually easier to get greasers out of the ERJ in a moderate x-wind.

I think the strongest winds I've flown in were about 35 gusting to 50, but it was more or less right down the runway. If you encounter winds much stronger than that, you will experience windshear most of the time, and that requires a go around.
 
very interesting info... not sure, but what does ground speed have to do with landing? (as long as its not like 50 on a airbus I guess lol)

<never flown an airbus but...>

The airbus commuter decides how much control movement it will allow. Depending on the phase of flight a full right stick input may result in different amounts of aileron movement. In other words, you are just suggesting to the computer where you want to go and then it decides if it is going to go there or not.

So with nasty crosswinds, especially when it is gusty, sometimes throwing the stick all around the place doesn't get the effect you want. The ground speed is probably one of the many factors the computer looks at before deciding how much roll to actually throw in.
 
<never flown an airbus but...>

The airbus commuter decides how much control movement it will allow. Depending on the phase of flight a full right stick input may result in different amounts of aileron movement. In other words, you are just suggesting to the computer where you want to go and then it decides if it is going to go there or not.

So with nasty crosswinds, especially when it is gusty, sometimes throwing the stick all around the place doesn't get the effect you want. The ground speed is probably one of the many factors the computer looks at before deciding how much roll to actually throw in.

I know that this is not true, it is one of the many myths out there.

The Airbus uses C* control law, the 777 uses C*U. The only difference is that, in an amazing bit of inanity, the 777 requires you to actually manually trim the thing (sigh).

In either case, the law is a rate input.

Separately, the Airbus (and the 777 to a lesser extent, and contrary to recommendations from CAST and FSF, et al, plus IBP) has envelope protection, to prevent exceeding various limitations.

Neither of these should impact the landing in the conditions above, from my recollection of the system. More likely, the issue was either:
a: a lower crosswind demonstrated number;
b: company limitations requiring strict adherance to the manufacturer demonstrated number, or, perhaps, a lower limit set by the operator;
c. Airbus sense of a windshear due to differential between GS and TAS which led the system to increase speeds for safety beyond stabilized approach criteria.

I recall being stuck on the ground in CDG due to our company requiring hard limits, while many other operators were departing as they left it to the Capt discretion. IBP (Industry Best Practices) is to use "hard" limits, incidentally. This was recommended out of the CAST ExCom off the LOC JSIT.
 
I flew today with a student in a 172. Wind was reported 20 gusting 27 but pretty much down the runway. The student got to see something different. i saw a gs of 38 on final on the gps.:)
 
I fly a C-150 and I won't take it out in more than about 20 knots of wind, but that's more a function of the airport and surrounding terrain where I'm at rather than the limits of the aircraft (we get turbulence and downdrafts off of nearby hills on windy days). When climb performance is only 300 or 400 fpm, hitting a 300 or 400 fpm downdraft during takeoff out of a short field can get kind of hairy.

I used to fly C-152s in the desert of eastern Washington and my limit was about 30 or 35 knots. I didn't mind flying in that much wind, it's the taxiing that gets me. The C-152 is so light, and has such a large surface area aft of the main gear, that it will really want to weathervane into the wind while taxiing. It takes a lot of differential braking and bursts of power to get it to go where you want it to.

I flew Piper Arrows a fair amount in Washington too, and never found a limit for them. As long as I could land into the wind, taxiing never seemed to be a problem, even in 30 knot winds.

Where did you fly that 152 from in Eastern Washington?
 
Back
Top