Max Demonstrated X-wind Componet
02-28-2007, 12:26 PM
#12
Moderator
Joined APC: May 2006
Position: ATP, CFI etc.
Posts: 6,056
A theoretical value for max crosswind obtained by a computer code with all the coefficients and assumed steady winds would be limited by pilot technique, and as such represents an optimized flight condition. Most crosswind landings are finished in a sideslip following a crab, and the transition takes some skill which varies with the pilot. You also would want a fudge factor in case of gust so you don't scrape a wing. In the end, the calculation would be a ballpark sort of thing at best. This is why test pilots are the best source of performance data.
03-04-2007, 12:19 PM
#13
Gets Weekends Off
Joined APC: Dec 2005
Position: FO, looking left
Posts: 1,057
Just don't do this.
P.S. Does anyone know if this picture is real?? I saw it on an april fools joke website. So I am not sure if they were making fun on the picture, or if they just photoshopped it. Thanks
P.S. Does anyone know if this picture is real?? I saw it on an april fools joke website. So I am not sure if they were making fun on the picture, or if they just photoshopped it. Thanks
03-04-2007, 12:57 PM
#14
APC co-founder
Joined APC: Feb 2005
Position: B777
Posts: 5,853
My money is on Photoshop, look at the flat spot on the left main tire and blur in the grass on the in the infield from. There are some other clues, but over all it's a pretty good job.
Fake or not, it does serve as a graphic example of why there a crosswind limitations for landing
Fake or not, it does serve as a graphic example of why there a crosswind limitations for landing
03-06-2007, 09:12 PM
#16
Flying Farmer
Joined APC: Jul 2006
Position: Turbo-props' and John Deere's
Posts: 3,160
**Pic is photoshopped definately**
On Topic:
I think everyone's got great opinions, and I agree. It's a guideline, but as stated above, 38kts for the 777, that's pretty much a max anyways. My take on components above demonstrated are that you if you aren't proficient, 50% MDXW is your max. Avg pilot can probably take MDXW, and a proficient pilot in most cases can take 150% MDXW with a fight.
It's when you get 100%+ you need to take precautions in aircraft configurations and alternative airports as a better option. Personally, I just keep the flaps up and use differential thrust in my twins, and I've taken 200%. If I was in a single engine plane, high-wing I'd take maybe 125% max, low-wing 150%. Just based on it's weight vs speed @ landing etc...
On Topic:
I think everyone's got great opinions, and I agree. It's a guideline, but as stated above, 38kts for the 777, that's pretty much a max anyways. My take on components above demonstrated are that you if you aren't proficient, 50% MDXW is your max. Avg pilot can probably take MDXW, and a proficient pilot in most cases can take 150% MDXW with a fight.
It's when you get 100%+ you need to take precautions in aircraft configurations and alternative airports as a better option. Personally, I just keep the flaps up and use differential thrust in my twins, and I've taken 200%. If I was in a single engine plane, high-wing I'd take maybe 125% max, low-wing 150%. Just based on it's weight vs speed @ landing etc...
06-03-2007, 06:35 PM
#17
On Reserve
Joined APC: Jan 2007
Posts: 17
Flying in oklahoma, you find out rather quickly that it is not a limitation. Especially when an airforce T1 overruns the active runway 
and the hot brakes start a grass fire and you have to land with a 28 knot x-wind component in a 152 or divert to another airport. (I recommend the diversion!)
and the hot brakes start a grass fire and you have to land with a 28 knot x-wind component in a 152 or divert to another airport. (I recommend the diversion!)
06-03-2007, 09:30 PM
#19
Gets Weekends Off
Joined APC: Apr 2007
Posts: 606
06-06-2007, 09:27 AM
#20
Gets Weekends Off
Joined APC: Mar 2006
Position: rj 700/900
Posts: 506
Max xwind is more for legality reasons. I think the 172 is 15 knots, I know some to land them in {edit} knots and do just fine, you just have to keep your forward speed for effective airflow over your control surfaces. The stronger the xwind the less flaps you should use to keep your airspeed up (assuming you have appropriate field length). When you slow you are at the winds mercy, ie. full rudder deflection, and max aileron use and you still drift, or slide on the runway. When lift dies, you need now to be concerned with gusts fliping the plane. Be carefull. Best to just do touch and go's if you’re exceeding your demonstrated xwind component. Although your flight school probably have their own limitations that you should comply with.
Last edited by bla bla bla; 06-06-2007 at 09:33 AM.
