World Library  
Flag as Inappropriate
Email this Article

Lomcevak

Article Id: WHEBN0003090916
Reproduction Date:

Title: Lomcevak  
Author: World Heritage Encyclopedia
Language: English
Subject: Flight Unlimited, Chuck de Caro, Radio-controlled aerobatics
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Lomcevak

A Lomcovák is a family of extreme aerobatic maneuvers where the aircraft, with almost no forward speed, rotates on chosen axes[1] due to the gyroscopic precession and torque of the rotating propeller.[2]

Etymology

The word originates from the Czech aerobatic pilot Ladislav Bezák's mechanic at the 1958 air show in Brno, Czechoslovakia. When asked by journalists what Bezák's tumble maneuvers were, jokingly called them Lomcovaks explaining it means headache.[3]

The expression Lomcovak is commonly used in Moravia to describe the rotating motions of one who has had one drink too many of its famous alcoholic drink Jelinek slivovitz.

In the 1940s Czech aerobatic pilots called this a Talířek which means a small saucer, after the horizontal rotary movement of the aircraft.[4]

Description

The Lomcovak is a family of freestyle maneuvers performed at airshows. It is not in the Aresti catalogue and therefore may not be flown in competition.[2]

Lomcevaks are very disorienting but otherwise fairly gentle for the pilot. However they are highly stressful on the aircraft structure and should only be performed by aeroplanes built for aerobatics. The worst effects are on the engine mounts, crankshaft and propeller. There have been quite a few cases of major damage to these components during Lomcevaks.[2]

The Aermacchi MB-339 was declared in 2012 the only jet airplane in the world that could perform a true Lomcovák.[5]

Flying techniques

Flying a Lomcevak will vary in technique from aeroplane to aeroplane and pilot to pilot.[3] Perhaps the most difficult thing about flying them is to use the throttle not as a speed control, but as a control of the gyroscopic precession and torque. There are at least five basic Lomcovaks, each one with several derivatives.[1] These are the three most common types:

The Main Lomcevak

Intention: tumble the airplane continuously with each tumble's plane turned relative to the previous one. Enter from a near vertical climb then let the airspeed decay to near zero and initiate a snap roll by using full down elevator and, for a clockwise rotating engine, full left rudder. The aircraft will rotate on all three axes and perform three end-over-end negative "g" tumbles, each tumble being at about 45° to the plane of the last.[1] The maneuver ends when it runs out of momentum and the aircraft begins falling with enough speed for the airflow past the tail feathers to stop the tumbling. Neutralise all controls and the aircraft will recover nose down.[2]

The Cap Lomcevak

Intention: execute a outside loop of 360° with the lateral axis vertical to the earth.[1] Enter from a Hammerhead (Stall Turn) and as the fuselage reaches knife-edge flight at the top give it full down elevator. The resulting will be the aircraft will pivot about its wing tip in a perfect pirouette.[2] Use the throttle as the control to make the wing remain vertical.

The Conic Lomcevak

Intention: make the fuselage trace a cone inclined at 15° to the vertical. The Positive variant uses the nose of the aircraft as the focal point and has the tail describe a full horizontal circle. The bottom of the wing is tangent to the surface of the cone during the entire maneuver.[2] Close the throttle as soon as rotation starts and opened it to recover. Exit using a Hammerhead or a Tailslide.[1]

References

External links

  • Diagram of a 45°-Up Lomcevak Fighter Combat International
  • Videos of performances of Lomcovak O V Guide.

Template:Aerobatics

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.