Torgue is a roll moment but to an aitplane its is countered by rudder not airleron.
Lets take a P-51, its a tail dragger the nose sits in a high angle of attack to the relative wind which is paralle to the runway, P-factor, prop slip stream and gyro pressesion is all present at the onset of power application.I
In AH on autotake off you see the airlerons move up and down at the intial onset of takeoff power, why are they moving I dont know and rudder doesnt move at all. 1. There is no airflow across the wing at zero airspeed to make airlerons effective. 2.Rudder is in the prop stream and is the major control device thats is controlling the airplane from a left turning motion at this time. 3.Elevator is also efective because of slip stream. Torgue is trying to roll the aircraft to the left along with P-Factor, prop slip stream and gyro-prossesion which moves to the right. Rudder is used to counter this moment airlerons are not effective still, not enough airspeed to counter anything. The left landing gear is now the pivet point and is bearring the brunt of the torgue. The plane is not going to roll over on the ground but will pull to the left because of drag and weight on the left main tire, it feals like the brake is applied. Power is applied smoothly if you run out of rudder and the planes still is pulling to the left get of the power there is nothing else thats going to stop you from going off the left side of the runway except this or cheating with brake on the right side.
Around 45 kts airlerons become effective it varys on different airplanes, but this still doesnt counter torgue you cant roll an airplane still on the runway rudder is still used . Once you get airbourne everbody thinks the airplane is going to roll opposite direction of the torgue this is not true. Rudder maintains direction controll fine and roll moment. Now suppose we use airleron in stead of rudder after takeoff here is whats happens you roll the airleron to the right to counter torgue, the left airleron moves down increases angle of attack, increases cord length, increases lift and increases drag. Which slows the left wing, the right wing speeds up due to decrease in lift and drag now the airplane yaws to the left in the direction of the torgue if more airlerons is used to counter this left turning moment this situation gets worse the same is true on the runway. If your trying to maintain a heading after takeoff this is not possible the airplane keeps pulling to the left if you were not use right rudder while the airleron is used you would be cross cordinated the ball would not be centered and you could not hold a heading but drift only to the left.
But in AH, airleron is only used with no rudder. Now if you took off with no autopilot all you need is rudder no need for airlerons. I dont understand by watching the airplane on takeoff in auto whats its trying to do. The airplane moves left and right on the runway with airlerons deflection , on full power application, as the wheels start turning there is no airspeed to make airlerons effective no airflow, but the plane moves left and right anyway because of this, and the rudder doesnt even move. UHH! Please explain. By using no autopilot on takeoff this is a more realistic takeoff using rudder only with no need for airlerons for roll moment.
Yes you get a roll moment from torgue but airplanes are designed with anti left turning moments. The right wing is mounted to fuselage at a higher angle of incidence then the left wing, the vertical stabilizer is mounted to the fuselage with more angle of attack to the left side of the airplane. the engine is mounted nose down and to the right from the center line of the airplane this is all to counter torgue, slip stream, P-factor.
If you were to lose airlerons in flight, say the cables broke or something your roll moment can be aquired by rudder. Rudder is also used to cordinate the airplane in a turn, when you roll into the turn, you use rudder into the same direction of the turn because in a turn the lower wing always speeds up pushing the nose in the opposite direction of the turn you use rudder to bring the nose back in the direction of the turn. Airlerons only gives you bank angle for a turn, horizontal componite of lift is what turns an airplane.
Crosswind takeoffs is were you use airleron for take off. You start with full airleron deflection into the wind as airspeed increase you minamise airleron as they get effective enough to kill the drift, use rudder to point the nose this is a forward slip take off. Once airbourne use rudder to hold heading and airleron is no longer required.
Rudder is used to stop the roll moment on takeoff not airleron.
Multi-engs have the same principle but a little differant in an engine out condition. I have a lot of high performance twin time (King Air 200 & 350) to name a few and my right foot gets a work out on takeoff.
Thanks talk at you later.
Hitech what kind of RV you have? I have help build and fly some friends with a RV - 6 and 8 funs toys.
