[NOTE: sent to me by mistake, I'm forwarding on -Tom] Keith: Now I don't have a lot of time in Ercoupes, actually never even landed one. But I do have about 3500 hours of military flying time, and I am somewhat confused about this turning away from the wind thing of yours. All the aerodynamics training I ever got (and the military tends to overdo things like that) is telling me there's something wrong with your technique. If I'm landing with a crosswind from the left, and my left wing comes up, and if I steer AWAY from the wind, ie to the right, then my left aileron will be deflected DOWN, which should increase the lift on the left wing, and if anything cause the problem to worsen. Also, your point about turning the fuselage into wind will have the opposite effect that you were hoping for: it will blank the right (downwind) wing destroying lift on that side. Again, no help there. Lastly, turning out of the wind will increase the relative airspeed under the left wing which should lift it too. The only possible reason that I can see that steering away from the wind will help in this instance is possibly by causing a ground steering rolling moment opposite to the direction your turn. After all, at this point in your career, your just driving a 75 mph trike. More likely the wing was just going to go down no matter what you do, just because that's what it does! (A tribute to the excellence of the design) I would suggest that this airplane is so bulletproof that even the wrong inputs on landing makes you look good! (no offence) Ah take it easy now, maybe I'm just frustrated cause it's taking so long to get CF-JGW in the air. Spike -----Original Message----- From: coupers-digest <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Date: Wednesday, February 10, 1999 2:21 PM Subject: coupers-digest V1 #112
> >coupers-digest Wednesday, February 10 1999 Volume 01 : Number 112 > > > > >---------------------------------------------------------------------- > >Date: Tue, 9 Feb 1999 09:22:15 -0500 >From: [EMAIL PROTECTED] >Subject: Re: > > >Date: Tue, 09 Feb 1999 14:46:07 -0800 >From: Keith <[EMAIL PROTECTED]> >Subject: Re: few questions! > >At 03:35 PM 2/9/1999 -0600, you wrote: > >>>>>=20 > ><excerpt>At 10:45 AM 2/9/99 PST, you wrote: > >>I=B4ve few questions for you guys. =20 > >>Have you had a problem about the ventil on the fueltanks? Mine leaks=20 > >>fuel, it overflows also during flying, so I grounded it. Pump should=20 > >>pump fuel from wingtanks to the center tank, right? Can anyone give me=20 > >>describtion for crosswind-landings, in details? =20 > > >Landing in a cross wind in a Coupe is probably the most misunderstood >skill there is. First, on final crab as much as is required to hold the >centerline. As you flare for touch down hold it off as long as possible. >Do not let it settle in any earlier than possible. Bleed off every bit of >forward speed possible. This is to minimize the stress on the mains as >well as minimize upwind wing lift. On touchdown the nose will swing >around and track straight ahead without action on your part. Many pilots >will advise you to push the yoke forward to "nail the nose gear". This >can get you into trouble by causing the aircraft to wheelbarrow making it >light on the mains. Slight or gentle forward pressure may be of some >benefit if your Coupe's tail is low. If the crosswind is strong be >prepared for the possibility of the up wind wing to raise as it swings >around. This is simple aerodynamics, as the upwind wing swings around it >picks up speed, which equals more lift, enough lift and the wing flies,=20 >the down wind wing is retreating and therefore loosing lift. Unequal lift >on the wings and the one with the most will lift. This may be no more >than an inch, but could be enough to lift one main completely off the >ground. In the event the upwind wing does lift completely off the ground >or even almost off DO NOT touch the brakes. If you do you will only be >applying brakes to one main. Remember you would be running along only on >the nose wheel and one main. This will cause an exit of the runway in >very short order at the least, and rolling it up into a ball at the >worst. While it may seem like an eternity the upwind wing will settle >back down in a second or two. You can, only if well disciplined, steer >ever so slightly into the upwind wing which will hasten it's return to >normal level position more quickly. The coupe has the highest certified >crosswind component of any production aircraft. It will far exceed that >if needed. Like anything else that has established limits they should not >be exceeded under normal circumstances. Both myself and a friend have >personally landed in a 45KT direct X-wind. No it was not fun, but it >wasn't as bad as some other experiences I've had either. It's not >something you do for kicks but should the need arise it is nice to know >it can be done. Take your time, don't rush it and get the feel of your >aircraft before you attempt much of a X-wind. As you get the feel you >will find you can fly comfortably when all the others are still in their >hangers. > > ></excerpt>____________________________________________ > >While Dave's answer is a pretty succinct answer to this common question, >I would offer a differing opinion on a few points. > > >1. I wouldn't worry too much about bleeding off the forward speed. It is >always nice to get it slowed down, but the airplane is designed to land >at its cruising speed and the amount of side load on the gear is so >transient, it really is not that much of an issue.=20 > >2. If the wing does come up, and I have had this happen on a number of >occasions (although I'm not in that selective club who has the 45kt >experience) you can do one of two things to bring the wing back down. >Slight brake pressure applied just once will usually do it, or a slight >one time push on the yoke. > >3. If you are going to change direction, DO NOT STEER INTO THE WIND, >steer away from it slightly, the aerodynamic push of the wind will put >the upwind main back on the ground. It is not a dissimilar aerodynamic >function than a forward slip where you use the fuselage to destroy=20 >lift. > > >Other than that, enjoy them. The first one is a leap of faith. From that >point on, they are close to a non-event. > > >Keith > >N5663F > >------------------------------ > > >Karl, > >I was trying to point out that Dave's comments were/are misleading. To >think you have to be overly concerned about bleeding off speed is >erroneous. Carrying a little extra speed does not place an undue stress on >the mains. In fact, the reverse is likely to happen. The slower you get on >a crosswind, the less effective the controls and if you have misjudged the >flare, you are more likely to drop it in which will substantially increase >the load on the mains. Second, it is clear that Dave has limited experience >in landing in crosswinds. Had he landed a conventional tricycle gear in a >strong crosswind, he would know that a slight tap of the brake for the main >on the ground doesn't send the plane off in the direction of that main >gear. That's just another theory of low time pilots whose primary flight >experience is hanger flying. His comment about turning into the wind is >absolutely wrong. By turning slightly away, in a crosswind take-off or >landing, puts the fuselage into the wind. The combination of that plus the >slightly down aileron drops the wing. Example: last Saturday I flew into >Hillsboro, Oregon. Landing on Rwy 35, I had an 18 kt wind blowing from 320. >I set up the crab, held the a/s at 80 mph. Immediately on touch down the >coupe straightened out and the left wing came up enough to pull the left >main up. I turned slightly to about..355. Bingo, the wing was down >instantly. A little common sense and an understanding of how planes fly >goes a long way. > >Keith >5663F
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