A SIGNIFICANT FACTOR of which we seldom speak is the fact that the largest single contributor to the Coupe crosswind capability is not crab, nor slip. It is the fact that the bird comes over the fence at 80 mph and lands not a lot slower. This, mathematically speaking, decreases the crosswind component vector effect on the Coupe side travel. In other words, over a given distance of travel, a 25 knot crosswind has half less effect on a bird traveling 80 mph that is does on a bird traveling 40 mph. Straight vector analysis. This can have a major impact on touchdown. The added benefit of slip sill not really contribute much. Dave W -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of fnelson913 Sent: Thursday, February 07, 2008 7:15 PM To: [email protected] Subject: [ercoupe-tech] Re: rudder pedals and strong crosswind landings Thanks, Ed. I like your argument about the loads on a single main gear touching down in an extreme crab. I am sure that I won't try to test these theories one way or the other, but my instructor was curious. When life, limb and the fate of a 60 year old aircraft are at risk, I don't think that I will be collecting test pilot data on this one.
Frank Nelson --- In ercoupe-tech@ <mailto:ercoupe-tech%40yahoogroups.com> yahoogroups.com, "Ed Burkhead" <[EMAIL PROTECTED]> wrote: > > > Frank Nelson asked: > > This is an excellent point, Jerry. If an Ercoupe that can handle > > 15 knots of crosswind using a standard landing, then it would > > seem that such an Ercoupe could use combination of rudder > > and crabbed landing to land in a 45 knot crosswind. Is this true > > or am I just dreaming? Does the addition of rudder pedals > > increase you ability to handle crosswinds? > > The majority of my Coupe flying was with rudder pedals. > > I found that up to a 15 mph crosswind component, I could land one- wing-low > with the nose aligned with the runway/direction-of-motion. > > With crosswind components in excess of 15 mph, the rudder effectiveness was > insufficient for that technique. So, in stronger crosswinds, I leveled the > wings and landed in a crab like any two-control Coupe. > > While I can conceive of landing in a strong crab, one wing low, it > distresses me to think of it. Here's why: In a normal crabbed landing, > both main gears touch at about the same time so the side loads are handled > by both main gear legs. If you land one wing low AND in a strong crab, the > upwind main gear will touch first, by itself, and may take unacceptable side > loads. Then again, the side loads may not be a problem even in this > situation. I don't know - never tried it. > > Me, I landed wings level in a crab whenever the crosswinds were very strong. > Probably 35 mph crosswind component was the strongest I ever did. A 30 mph > direct crosswind didn't faze me landing on a 20 foot wide asphalt runway > once on a cross country trip (well, I sweat some but it turned out to be a > non-event). > > The 25-30 mph crosswind components I had on several wider runways on many > occasions were, similarly, not a big deal. > > Interestingly, when you get down to the last 1'-9' altitude, you get a > dampening of the turbulence from the ground effect and that helps make for a > controlled touchdown. My technique was to keep the airspeed a bit high till > I was level in ground effect at about 3'-8' high, then bleed off the > airspeed and let it settle down. > > If the crosswinds were much stronger than the strongest I landed in, I could > just about land across the runway or on the 100' taxiway. With a net ground > speed less than 20 mph, stopping doesn't take very long. (Facetious humor - > kids, don't try this at home!) > > Ed >
