Maximum Demonstrated Xwind Component

[canav8]

How many of you guys know why there is no Max. Demonstrated Crosswind component for your C-170 aircraft?


First I would like to disclose that I did not remember this from any of my readings in the last 30 years but finally answered an age old question. How did they get a Maximum Demonstrated Crosswind Component for a Certified Aircraft and why doesnt my C-170 have one?





Answer:

Airplane Flying Handbook page 8-16

Before an airplane is type certificated by the FAA, it must be demonstrated in flight to be satisfactorily controllable with no exceptional degree of pilot skill or alertness in 90 degree crosswinds up to a velocity equal to 0.2Vso. This means a windspeed of two-tenths of the airplanes stalling speed with power off and landing gear/flaps down. Regulations require that the demonstrated crosswind velocity be included on a placard in airplanes certificated after May 3,1962.

The C-170B has a Vso of 52 mph. Given this little tidbit of info, my 170 should have a max demonstrated crosswind component of 10.4 mph. This is not a limitation though. Now I know how they came up with that!

[GAHorn]

...The C-170B has a Vso of 52 mph. Given this little tidbit of info, my 170 should have a max demonstrated crosswind component of 10.4 mph. This is not a limitation though. Now I know how they came up with that!

Actually, that would be a MINIMUM crosswind component the aircraft must demonstrate...but that is only if the aircraft type were to be certified under TODAYs regulations. It is not a limitation for several reasons in addition to our airplanes are not req'd to meet that rule. (And everyone knows that as taildragger pilots, we all have much more than "exceptional degree of pilot skill")

[blueldr]

canav8,

If tou want all that neat information like Maximum Demonstrated Crosswind stuff, you need to get a lot newer airplane.

When it gets too rough for all you new guys, it's just right for old guys!

[canav8]

canav8,

If tou want all that neat information like Maximum Demonstrated Crosswind stuff, you need to get a lot newer airplane.

When it gets too rough for all you new guys, it's just right for old guys!

Hey Blue, Actually I found it interesting thats all and thought I would share. Actually since recently my company just reduced my Max Demonstrated Crosswind component after they added winglets to our Boeing 737-800's I wanted to know why. After explaining it to a student and he asked follow on questions, I read the Airplane Flying Manual and informed myself. I refrained from saying what the true Max demonstrated Crosswind component is in the Cessna 170B, but I can tell you that you run out of Aileron first not Rudder and that is with Flaps Up. Fortunately I am one of the older guys that gets the looks from the Coffee Kronies at the airport. Just ask some of our members about crosswind training here in Hell! Mojave Desert in the Spring time. Today winds are blowin 35 knots. I was out again doing a little crosswind practice. All in good fun! Doug

[blueldr]

canav8,

Have you seen that really neat video of the big Boeings being tested in crosswinds down in Brazil? If not, try Googleing it up. It's pretty amazing.

[canav8]

canav8,

Have you seen that really neat video of the big Boeings being tested in crosswinds down in Brazil? If not, try Googleing it up. It's pretty amazing.

Yup sure have. It is pretty awesome. For anyone else that is curious as to what Dick is talking about here is the link:
http://www.youtube.com/watch?v=ljOxo0s33sI
Then if you like the crazy Toad sucker version you get this one.
http://www.youtube.com/watch?v=TwyVZtSU ... re=related
Enjoy,
Doug

[bsdunek]

canav8,

If tou want all that neat information like Maximum Demonstrated Crosswind stuff, you need to get a lot newer airplane.

When it gets too rough for all you new guys, it's just right for old guys!

I always thought our 170's were built when pilots were pilots and just flew the airplane. Didn't need all those numbers in a book.

[canav8]

canav8,

If tou want all that neat information like Maximum Demonstrated Crosswind stuff, you need to get a lot newer airplane.

When it gets too rough for all you new guys, it's just right for old guys!

I always thought our 170's were built when pilots were pilots and just flew the airplane. Didn't need all those numbers in a book.

Actually Bruce, the Airplane was built when landing areas were fields not rectangular strips in a lot of areas. You would land into the wind in any direction. now that we have a runway in 2 directions, it is a little harder to do the same job because of the crosswinds. That is why there is so few tailwheel instructors and so many pilots that admire a tailwheel pilot. We dumbed the airplane down and put training wheels on airplanes so more people could fly. It is kind of like after WWII, Volkswagen started producing cars so everyone could own one because they were cheap. Your still a good pilot though! Doug

[GAHorn]

My method to determine cross-wind capability: If you're on long, final approach, (and on-speed for touchdown) and if you set-up a side-slip with upwind wing down, and opposite rudder to prevent turning...and if you cannot remain on extended centerline of the runway with bank-and-rudder... then you are probably experiencing too much crosswind. Gusts make it important to have available additional aileron/rudder.

[Brad Brady]

As mentioned before, Max cross wind component is what ever you can handle. The book figure is what the cross wind was the day the aircraft was certified. And everyone knows you can find a 15 Knot cross wind in Kansas on any day!

[bsdunek]

canav8,

Actually Bruce, the Airplane was built when landing areas were fields not rectangular strips in a lot of areas. You would land into the wind in any direction. now that we have a runway in 2 directions, it is a little harder to do the same job because of the crosswinds. That is why there is so few tailwheel instructors and so many pilots that admire a tailwheel pilot. We dumbed the airplane down and put training wheels on airplanes so more people could fly. It is kind of like after WWII, Volkswagen started producing cars so everyone could own one because they were cheap. Your still a good pilot though! Doug

As I recall, there were already a lot of airports with runways when the 170 was conceived. My Dad learned to fly at KristPort http://www.airfields-freeman.com/MI/Air ... it_NW.html which was transitioning from an all way field to runways in 1946. He had to land his T-Craft in a cross wind back then.
I think they just didn't put all that stuff in the hand books then. Pilots just learned how to fly in all conditions. In any case, yes, we taildragger pilots learn how to land, or when not to, and are proud of it. (or not, when we take out a couple of runway lights).
Hope to see you and everyone in July.

[krines]

I purchased my 170 and got a cfi and learned how to fly. The first day out the winds where 24-40 at 30 degrees to the runway. Prior to departure I asked what the max Xwind component was for the plane as it was not outlined in the manual. My instructor said the max Xwind for a 170 is when you have to land on one wheel and one wingtip. Some little castor wheels might be helpful installed on the wingtips. Steve