Knife-Edge Spin

1 J-70 DASPHASE IIIK nife-Edge SpinLomcevak (tumble)J-71 DASPHASE IIIKPTR: The lomcevak should satisfy the urge to gofrom time to timewithout needing to radically reconfigure one s entire plane and radio continuously, land only to notice people have been going about their own business!As a show maneuver, the lomcevak has a greater effect on spectators when performed nearthe end of a flight, or as the flight s finale: After landing, you will likely have people comingup to you reflecting the obvious impression your flight made upon them. Whereas, those whotumble. throws and extensive programming).

2 The lomcevak variant featured here starts out as inside snap rolls ona near vertical upline, and then by transitioning the elevator to fullThe reason for featuring the lomcevak in anprogram isthat it is possible to achieve the end over end lomcevak tumble withconventional aerobatic control surface throws by harnessing gyro-scopic precession to effect the tumble (as opposed to huge controlSome thoughts on the lomcevak from one who grew up in Oshkosh,Wisconsin, home of the Experimental Aircraft Association and theworld s largest civilian aviation convention and airshow, and aveteran of several hundred airshows: As a show maneuver, thecatch 22 of tumbling gyroscopic maneuvers like the lomcevak isthat if performed early in one s routine, spectators tend to expectthe rest of the maneuvers to be just as sensational.)

3 If not, theirimpression of the flight and interest tends to diminish. However,if the pilot continually performs tumbling maneuvers, after aboutthe 2nd or 3rd one, spectators start losing interest watching anotherAerobaticsCCunbalanced swaying of a person who has had too much to drink).This program will feature one 3D freestyle maneuver for show. For those who have notalready observed 3D flying, the simplest explanation of 3D flying is any maneuver in whichthe airplane is seen to do things that one would not normally expect an airplane to be able todo. 3D maneuvers have names like the, the, the, and the grand-daddy of 3D maneuvers that started it all, the(a Czech word used to describe theblenderwaterfallharrierlomcevakLomcev ak(makeshift aresti symbol)Lomcevak (lum-shu-v c)@Lomcevak tumbleforward, the airplane is made to tumble forward end over C-13J-72 LomcevakDASPHASE IIIand pull create the correct maximum gyroscopicforces and the best chance to achieve thelomcevak tumble, maintain maximum rpm s,briefly set the upline slightly short of vertical,and start snapping to the right.

4 After snap, quickly but smoothly transition theelevator to full forward while maintainingright aileron and thoseinputs through the tumble. To recover, simplyneutralize the controls, gain some airspeed,KPTR: The airplane will rapidly snap out of the climb without tumbling if the entry is not near Inside Snap RollLomcevak Transitionthe entry is too shallow.)little airspeed.)While space does not permit covering all that is involved,what primarily causes the plane to tumble is the rightrudder exerts a force on the spinning propeller, creatinggyroscopic precession that has the effect of applyingadditional forward elevator.

5 The forward elevator createsgyroscopic precession that resists the rudder force andstops the plane from yawing. Consequently, all the energyhas only one way to go: Triggered by the movement of theairplane transitioning from pitching inside to outside, theairplane pitches forward with such force that it tumbles endover end. (The right aileron is maintained to prevent theplane from torque rolling as it enters the tumble with verySide note: A near vertical entry is important for gravity toslow the airplane enough for it to tumble. (The plane willlikely snap out of the climb and into a Knife-Edge spin ifwhich effects the most distinctive : For various reason, you may have toexperiment with different entry angles to findJ-73 DASPHASE IIIKPTR: Initiate the lomcevak higher than usualin anticipation of entering a spin Transition into a SpinorRight Upright spin TransitionLomcevakRight Inverted spin TransitionLomcevakMaintaining the lomcevak inputs after the tumble will put the airplane into a Knife-Edge spin .))

6 Or, onecan change the pace by transitioning into a right upright or inverted spin immediately after the Spinenough :Try changingthe amount of aileronyou are holding ina knife -edgeThe plane will rapidlylose altitude duringa Knife-Edge spin , sobe sure to start it withtoremove any bankingduringdown after the of the pilot!Tip: As a show maneuver,the lomcevak is typicallyentered at a lower altitudeto increase visibility. Thus,with minimal altitude towork with, start spinningas soon as the nose pointsSide note:Not all planeshave all the right ingredients, , big enough props, to beable to tumble end over endwith conventional such instances,pulling off the power andentering a spin after attempt-ing to tumble is a great wayto impress upon people th