Aerobatics - The Lamcovak (Lomcovak or fr. Ruade) in a DR107

DR107 EAA One Design and the Lamcovak

Transcript.

This video is for entertainment only.

I am not an instructor and am just this bloke entertaining himself pottering around in his airplane.

This figure is known to many as the Lamcovak. Apparently, it roughly translates into English as, “headache.” It is relatively gentle on the human but is very hard on the airframe, engine and propeller. When flown towards or away from the spectator, the plane appears to tumble nose over tail while suspended in the air.

It is a relatively low speed figure being initiated at an air speed that would be normal for a snap roll. High air speeds hinder the process. We want gyroscopics to dominate over aerodynamics.

It is one of the easier tumbles to execute in a monoplane and is usually taught differently than what is shown here. Most folks would advise starting the figure from a left-hand knife edge in a climbing attitude.
The reason being that the climb helps minimize loss of altitude and the knife edge helps load up the aircraft for the impending yaw input.

The Lamcovak can be initiated from almost any attitude and in this case I start from a relatively straight and level attitude. Right rudder and up elevator is used to setup up a pendulum effect to magnify the effect of left yaw and forward pitch when it is introduced. I have used this technique in three DR107’s, an MXS and an Extra 330LX – all monoplanes. I was never able to get more than one turn out of my Pitts S1T, possibly because the ailerons are relatively small making them ineffective and perhaps the biplane wings interfere.

Note that in this plane the airspeed is on the left of the display and the altitude is on the right.

Clearly visible here is a large loss of altitude even when everything goes right. So it is important to have plenty of sky below you, especially when new at it. Here, each figure was started at between 7500 ft and 6500 feet, with about 1500 feet lost for four tumbles. The ground is between 1500 feet and 3000 feet amsl. Before doing this, be very comfortable with recovering from unusual attitudes and spins of all sorts.
In the DR107, using between 100 and 120 knots seems to work well. Note how the airspeed oscillates between 100 knots and no reading during the tumble. On this plane the pitot tube is on the left wing and the static ports are on the aft fuselage.

As mentioned previously, a generous amount of right rudder is initially applied. This is not strictly necessary but is a good springboard. Just as the plane reaches its maximum right yaw the inputs for the Lamcovak can begin.

The sequence of control inputs is as follows. Full left rudder, followed immediately by full forward stick and plenty of left aileron – a good initial start is to push the stick all the way into the top left corner. The pilot focuses on the right wing and uses the aileron to steer the wing tip towards the direction of flight. The amount of forward stick and rudder regulates the rate of tumble. You can see in this video that I am being pulled out of the seat by the negative g and the stick and rudder follows me back a bit. This is what is causing the hesitation at some points in some of the tumbles in this video.

Due to gyroscopic effects..
Rudder gives pitch
Elevator gives yaw

To recover center all controls and then fly out normally.