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Old 05-26-2002 | 08:55 AM
  #14  
HarryC
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Default Getting the hang of it!

You've been flying you lucky lad! The weather here is so useless I have not flown for 2 weeks. One pupil phoned me at 7.55am yesterday to enquire if weather was good enough, I said I did not know as I had not got out of bed yet! At least he is still keen.

I see someone at rconline.com is telling beginners to line up model on finals with rudder, oh dear, please always ignore that nonsense. I think modellers see something we full-size pilots do but not knowing what we are doing they take it out of context and think that is how to fly a plane. If landing in a crosswind there are two ways to fly the approach. One is to side slip by pointing the plane along the runway then banking it into the wind. This causes it to sideslip into the bank and therefore into the wind, thereby compensating for the drift. Of course the plane then yaws into the turn so you have to hold on opposite rudder to prevent that. You actually flare and land the plane like that, landing on one wheel, the one into wind, then let the other main wheel down. That is a sideslip approach. The other way is simply to turn the plane (by banking) a little into wind so that the plane is pointing a little off runway heading to compensate for the drift. This is much easier since once the turn is complete, all the controls are back at neutral. Modellers utterly fail to understand this because from the ground it looks like the plane is travelling slightly sideways so surely the pilot is holding on some rudder and therefore modellers often, incorrectly, call this a sideslip when in fact it is perfectly straight flight through the air. Now here comes the bit that model fliers get out of context. On this type of approach the aircraft is pointing away from its direction of travel so at touch down the wheels will be pointing off to the side of the runway instead of straight down it. That imposes side loads on the bearings, the tyre/wheel joint, scrubs the tyres, and also makes the plane veer off in the direction the tyres are pointing. So an instant before touchdown we use rudder to yaw the plane out of balanced flight but point straight down the runway. Do it too early and you start drifting sideways across the runway which means you risk going off the side and anyway you are back where you started with the plane pointing one way and going another way. Modellers can misinterpret this last second use of rudder as using rudder to steer when in fact we are using it to push the plane out of balance!

Harry