ShawnC
Skirts Will Rise
- Joined
- Jan 17, 2002
- Posts
- 1,481
Jedi_Cheese said:What's the difference between a "barrel roll" and an "aileron roll"? Never done aerobatics and it didn't come up while flying my C152 during the private.
From the Acro Server:
Rolls
There are four different types of rolls:
- Aileron Roll
- Slow Roll
- Snap Roll or Flick Roll
- Barrel Roll
Aileron Rolls
Aileron rolls are flown with the rudder and elevator in the neutral position during the roll. The aileron is fully deflected in the direction of the roll. This is the easiest of the rolls to fly.
The aileron roll is started by pulling the nose up to 20 - 30 degrees above the horizon. The elevator is then neutralized and the aileron fully deflected in the direction of the roll. The controls are maintained in that position till the roll is completed. After the roll is completed the nose is usually 20 - 30 degrees below the horizon.
The aileron roll is not a competition maneuver.
Slow Rolls
Slow rolls have to be flown normally on a straight line (exception is the avalanche). The roll rate has to be constant and the longitudinal axis of the plane has to go straight. This requires constantly changing rudder and elevator control inputs throughout the roll. Hesitation or point rolls include stops at certain roll angles. The number on the base of the roll symbol describes the number of points the roll would have if it were a 360 degree roll. Allowed are 2 point, 4 point and 8 point rolls. The fraction on the arrow of the roll symbol describes what fraction of a full roll is to be executed. If no points are specified, rolling is done without hesitations. If no fraction is specified, a roll symbol that starts at the line specifies a half roll (see description of the Immelman). A roll symbol that crosses the line specifies a full roll (first figure). The second figure shows the symbol for 2 points of a 4 point roll (adding up to half a roll) from upright to inverted flight.
Snap Rolls
Snap or flick rolls also have to be flown normally on a straight line. A snap roll is similar to a horizontal spin. It is an autorotation with one wing stalled. In the regular snap, the plane has to be stalled by applying positive g forces. In an outside snap, the plane is stalled by applying negative g. In both cases rudder is then used to start autorotation just like in a spin.
Barrel Roll
The Barrel Roll is a not competition maneuver. I The barrel roll is a combination between a loop and a roll. You complete one loop while completing one roll at the same time. The flight path during a barrel roll has the shape of a horizontal cork screw. Imagine a big barrel, with the airplanes wheels rolling along the inside of the barrel in a cork screw path. During a barrel roll, the pilot experiences always positive G's. The maximum is about 2.5 to 3 G, the minimum about 0.5 G.
The good doctor does a much better job at describing them then I do.