Outside DAS Snap Roll - Outside Avalanche (Outside snap roll(s) atop outside loop) FLIGHT SCHOOL 1ST U.S. R/C - Inverted Spin - Inverted Flat Spin E-26
DAS (Negative) Outside Snap Roll All the rules that apply to inside snap rolls apply to (negative) outside snap rolls, with the obvious exception of using forward (down) elevator in an outside snap, and one other exception: While the ailerons effect the same direction of rotation whether the snap is inside or outside, the rudder in an outside snap effects rotation opposite the direction that the rudder is applied. Thus, the rudder must be inputted opposite the aileron to effect the same rotation as the aileron in an outside snap roll. During a right outside snap roll, full forward elevator is used to cause the wing to exceed critical (negative) angle of attack, with aileron and rudder both rotating the airplane clockwise to the right. A close examination will show that it is actually left rudder* that moves the tail clockwise in a right outside snap. In short, one must cross-control the aileron and rudder inputs in an outside snap roll. The direction the aileron is applied determines whether it is a left or right snap. In training, initially remembering the stick positions for each is aided by thinking of a left outside snap as a meter snap, with both sticks applied toward the traditional location of the transmitter battery meter. A right outside snap is an outside corners snap, or similar thought. Right aileron *Left rudder Yaw Roll Right outside snap roll: Simultaneously apply full forward elevator with right aileron and full left rudder. Most planes outside snap roll better to the right (with left rudder and help from slipstream) which many people also find more comfortable because their fingers don t have to stretch as far. Right Outside Snap Roll Both sticks out Left Outside Snap Roll Meter Snap E-27 KPTR: One must cross-control the rudder and aileron inputs with full forward stick to effect an outside snap roll.
Outside Avalanche DAS Whereas the typical stunt pilot might seek stimulus through taking risks and buying new equipment, the aerobatic pilot energizes his flying through nearly limitless variation and rearranging maneuver components to come up with new maneuvers. Here, an outside snap roll is added to the top of an outside loop to build an outside avalanche. After establishing a perfect parallel line with the wings level, an outside avalanche is performed with the pilot first pushing into an outside loop, then inputting an outside snap roll slightly before the top of the loop and snapping through the top. The snap is stopped (upright) with the wings perfectly level, and then the plane is pushed through to complete the outside loop. The plane will change course a little in the time that it takes the wing to achieve critical angle of attack while initiating the snap roll. So as you master the maneuver, stop the snap by returning the controls to neutral, except take the rudder past neutral into opposite rudder to correct the course, then smoothly take out the rudder. When multiple outside snaps are flown: Along with initiating the snaps earlier in the loop, accelerate the snaps by reducing the elevator to half once the airplane has started snapping in order to minimize the speed loss ( drag) and maintain the proper shape of the loop. At this point, students of Precision Aerobatics should emphasize their use of P-factor and rudder wind corrections during the first half of the loop to prevent any sideways drift prior to the snap(s). Neutral Resume pushing 9 3 Wings level 12 Right Outside Snap Roll Note: If you are holding in rudder prior to the snap, input the snap that requires rudder in the direction that it is already applied. A A Snap roll inputs (single) Snap roll inputs (double) KPTR: How comfortable you are inputting the snap(s) will be a direct reflection on how well you flew the first part of the loop. E-28
DAS Outside-inside 1½ Snap Avalanche: Snapping to an Attitude Another awesome avalanche variant is accomplished by performing 1½ snap rolls at the top of a loop, and to the awe of those who are able to discern what happened, completing the loop with the airplane in the reverse attitude it was in at the start. While stopping whole number snap rolls is somewhat intuitive, stopping fractional number snap rolls like 1½ requires an awareness of what attitude the plane needs to be in when the snaps are completed. In other words, since there is little time to count fractions of snaps, one instead snaps the airplane to a predetermined attitude. Neutral Start pulling Upright attitude start, snap to inverted (= 1½ snap rolls) 12 Right 1½ Outside Snap Rolls Example: When 1½ outside snap rolls are performed from an upright attitude start, one must be looking to stop the snaps with the airplane in the inverted attitude. 1 ½ 1½ 0 9 3 Upright attitude start: 1½ snaps = Inverted attitude finish You may find that performing the 1½ snap avalanche is easier when the first half loop is to the outside, so that in the event things get a little out of line, the corrections will be easier to make during the pull-out finish. Of course, performing the first half loop inside, executing inside snaps, and pushing out of the loop is another option. I ll do 1½ snap rolls at the top E-29 KPTR: An even 1 or 2 snaps requires little thought, but 1½ snaps requires you to think about the finish attitude.
Inverted Spin - Inverted Flat Spin DAS The inverted spin and inverted flat spin are uniquely satisfying in that they are not discovered by accident. The only pilots performing either of them are those who took the initiative to learn how to perform them. Since a normal inverted spin s rotation is similar to an outside snap, one must cross-control the rudder and aileron to effect the same rotation. With full forward elevator and the throttle at idle, the sticks end up positioned directly opposing each other. As unusual as that is, a sure knowledge of the stick positions is required before attempting inverted spins. Having projected a point where you want the spin to occur, reduce the power near idle well short of that point. Fly the plane straight and level on the edge of stall, and then just short of the point that you want the spin to occur, idle the engine and the stall will soon follow. At the moment the stall breaks, simultaneously cross-control the rudder and aileron with full forward elevator to initiate the spin. The best way to keep track of the airplane s position while spinning and stop on a precise heading is to count each revolution. When the plane nears the number (and heading) that you want to stop on, neutralize the controls just before you are about to think that revolution s number, and the plane will come to a stop on it. After lowering the nose to build up airspeed, one can finish the spin by smoothly adding power and either pulling or pushing out. Apply power Right Inverted Spin Left Inverted Spin Out-spin aileron Left Inverted Flat Spin Stall one Neutral two Invert. spin: Idle power, stall plane, cross-control rudder and aileron with full forward elevator. Recovery: Count revolutions one, two, and neutralize the controls just before two. Finish: Pull straight down, build up airspeed, smoothly add power and pull or push out. Due to the gyroscopic procession of the spinning propeller, only left inverted spins (with right rudder) can be transitioned into inverted flat spins, by smoothly switching to out-spin aileron and applying power. Recovering the deeply stalled flat spin should include full opposite rudder to hasten the recovery. KPTR: Those who fly a determined number of spin revolutions quickly learn how much altitude is lost, and what are safe altitudes to perform 1, 2, and 3-turn spins from. E-30
DAS Upright to Inverted Cross-over Spin An interesting spin variant is the cross-over spin where the pilot transitions a normal upright spin into an inverted spin. While cross-over spins are not permitted in precision aerobatic competition, they are sometimes used in a pilot s freestyle routine, or to mix things up a bit during a lengthy period of spinning, i.e., from a very high altitude start. Left Upright Spin Note that the time required to establish both upright and inverted spins on the same line will require this maneuver to be entered quite high. Since the airplane rotates in the same direction the ailerons are applied for both upright and inverted spins, the aileron is not changed when crossing over from upright to inverted; only the elevator and rudder are switched completely: Enter a normal upright spin. Once the spin is fully developed, quickly switch the elevator and rudder to produce a nearly seamless transition from upright to inverted spins. Crossing over from inverted spins to upright spins is another option, by quickly switching the rudder and elevator, while maintaining the same aileron. Cross-over to Left Inverted Spin Cross-over spin: Switch rudder and elevator, maintain the same aileron. E-31 KPTR: For the best effect, fully establish the upright spin(s) before crossing over to the inverted spin(s).