Lomcovak

Radar Contact

Radar Contact

Pattern Altitude
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Kevin
I've gone on a few aerobatic rides in the past 20 years. Starting with a Pitts S2B, an F16 ride, a P51 ride, formation acro in a T6, formation acro in an Extra 300 and in @EdFred 's Comanche around the pattern (maybe a couple others I missed). Somehow in all these flights and being around aviation for 2 decades I managed to miss hearing the term "Lomcovak".

My wife just went on her first acro flight (Extra 300) and she did one of these.

I asked a co-worker (former acro pilot in college) if he had heard of them and he said, "it's like having your body ripped apart". So I looked it up online to read about it.

Here is what Paul Bertorelli says, "I’d forgotten how unpleasant they are. Negative Gs pretty much suck and a lomcovak is carefully contrived to force all five quarts of blood north of the eyeballs. Molidor had me snug up the seatbelt ratchet before we entered the maneuver and if you’ve done one, you know why. If that belt ever failed, you’d come out of the seat and through the canopy like $#@% through a goose."
https://www.avweb.com/insider/you-want-a-lomcovak-with-that/

If it was possible, I have even more respect for my wife after acting like it was nothing. :)

Is this more common than I was thinking?

 
I was certain I was going to open this thread and find out someone did a Lomcovak in a 310...:eek:
 
GRG55 said:
I was certain I was going to open this thread and find out someone did a Lomcovak in a 310...:eek:
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Ha ha... I would've let Hoover give it a shot... While I was watching from the ground.

I was really curious if others had heard the term or if it's just a small faction of hardcore acro guys. I was surprised her pilot kept saying it like it was common but I had never heard it.
 
It was common “ish” in RC when I was in to that, though few people can do it.
 
Radar Contact said:
Ha ha... I would've let Hoover give it a shot... While I was watching from the ground.

I was really curious if others had heard the term or if it's just a small faction of hardcore acro guys. I was surprised her pilot kept saying it like it was common but I had never heard it.
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I used to hear the airshow announcers in the '80s and '90s use it often. I think that gyro maneuver was quite popular when there were more Pitts biplanes and similar on the show circuit. Now, with all the high powered beasts out there, it seems torque rolls with a tailslide finish have replaced it.
 
GRG55 said:
I used to hear the airshow announcers in the '80s and '90s use it often. I think that gyro maneuver was quite popular when there were more Pitts biplanes and similar on the show circuit. Now, with all the high powered beasts out there, it seems torque rolls with a tailslide finish have replaced it.
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Nah, biplanes never did them well. They are common as dirt among all the monoplane (Extra 300, etc.) airshow acts, which do them better. But in the acro world, few people actually use the term Lomcevak. Most just say 'tumble', meaning a maneuver that involves some degree of end over end rotation. Like the barrel roll, there are no standards for exactly how they are done. They are so common in fact that many acts are often labeled 'tumblefests'.
 
Having attended quite a few Dayton Air Fair events over the years, I was familiar with the manuever, but have no clue what control inputs it takes to get an airplane to tumble end for end.

Isnt Lomcovak, Chek for headache?

Sent from my SM-N970U using Tapatalk
 
That's what they always said about Lomcevaks @ OSH, Tim. First one I remember was when Leo Loudenslager introduced his first monoplane up there, although I remember Bob Lyjack doing something similar in his Waco Taperwing earlier.

Jim

PS- Come to think of it, Bob's ancestry was Eastern European....wonder if he coined the phrase?
 
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How soon before she’s looking for one of these on trade a plane?
 
I think most pilots who have any knowledge of aerobatics at least know what a lomcevak is, though few have actually done one.

In all my years of R/C flying I only ever had one model that was capable of doing one consistently... it was a Top Flite profile U-Control P-40 that I converted to R/C. Would have been around 1977.

Basically it's a transition between and inside and an outside snap roll where gyroscopic forces take over and make the plane tumble.
 
Dana said:
Basically it's a transition between and inside and an outside snap roll where gyroscopic forces take over and make the plane tumble.
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Naw that is not at all what a Lomcevak/tumble is. You do not enter a snap roll to start it. The most common way to do it is to climb 45, roll right knife edge and apply left rudder and forward stick. It can transition to a snap roll as it runs out of energy/tumble though. There's also not as much gyro force going on as people think. Modern acro planes use light composite props which cannot apply a ton gyro effect. It's more of an added force than a primary force to get the plane doing some sort of tumble.
 
RoscoeT said:
Naw that is not at all what a Lomcevak/tumble is. You do not enter a snap roll to start it. The most common way to do it is to climb 45, roll right knife edge and apply left rudder and forward stick. It can transition to a snap roll as it runs out of energy/tumble though. There's also not as much gyro force going on as people think. Modern acro planes use light composite props which cannot apply a ton gyro effect. It's more of an added force than a primary force to get the plane doing some sort of tumble.
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My technique was the 45° climbing knife edge, yes, but I would start an inside snap over the top (i.e. a right snap roll from a left knife edge), then as soon as the snap broke, push the stick into the opposite corner to transition into an outside snap in the opposite direction. If I was lucky I'd get two tumbles before it stabilized in an outside spin.
 
I don't know if it's common but it was amazing watching her go through some pretty tough maneuvers and when he asked if she wanted to keep going she'd say yep.
 
Kevin (& Jamie)
I really enjoyed that video.
Kind of a side note but interesting for me was the camera angle behind her head. I could be wrong but I imagined it as being a fairly close approximation of the pilot's eye view. The s-turning, landing, and the the rest. I felt like it did a nice job of "putting me in the cockpit" with them.
 
Dana said:
My technique was the 45° climbing knife edge, yes, but I would start an inside snap over the top (i.e. a right snap roll from a left knife edge), then as soon as the snap broke, push the stick into the opposite corner to transition into an outside snap in the opposite direction. If I was lucky I'd get two tumbles before it stabilized in an outside spin.
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Doing an inside/out snap still results in a snap at the end, which if you're going upward, it's gonna run out of steam and turn into some sort of random gyration, but that is just not how anyone enters a maneuver that is designed to maximize the degree to which you get real end over end rotation.
 
Brad W said:
Kevin (& Jamie)
I really enjoyed that video.
Kind of a side note but interesting for me was the camera angle behind her head. I could be wrong but I imagined it as being a fairly close approximation of the pilot's eye view. The s-turning, landing, and the the rest. I felt like it did a nice job of "putting me in the cockpit" with them.
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Glad you enjoyed it Brad! That forward looking camera was basically right in front of the pilot at eye level. He suggested it and it turned out great. My only fail was I should have had the wing view on the left wing. That was where the device (have no idea the proper aerobatic term) was that shows the angle on the horizon and the string he kept referencing. It was too late to switch it after I realized it. :)
 
If you'd like to see what a lomcevak looked like prior to the new super monoplanes with the "physics off" switch on the instrument panel search out Art Scholl videos on u tube...(the 1984el Toro vid is best) he would do really pretty ones that were fairly rare at shows.

Chris
 
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Scotty McCray flew aerobatics in a sailplane, in the 1970's, and performed the first Lomcevak in an unpowered airplane. I watched his program at Cumberland MD Airport many years ago. His finale was an inverted high speed run down the runway, cut a ribbon with his vertical stabilizer, climb inverted and roll with a turn, and teardrop 180, return and land.
 
geezer said:
Scotty McCray flew aerobatics in a sailplane, in the 1970's, and performed the first Lomcevak in an unpowered airplane. I watched his program at Cumberland MD Airport many years ago. His finale was an inverted high speed run down the runway, cut a ribbon with his vertical stabilizer, climb inverted and roll with a turn, and teardrop 180, return and land.
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Ho did he manage that without gyroscopic procession from a propeller?
 
Cap'n Jack said:
Ho did he manage that without gyroscopic procession from a propeller?
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Inertial coupling can give you a pretty good end-over-end tumble that looks a lot like a lomcevak, even on airplanes without propellers.

Nauga,
and that guppy magic
 
It was previously believed that gyroscopic forces were required to produce the 3 axis rolling motion, but he carefully analysed the necessary timing of stick and rudder application, and a Lomcevak resulted. Several of the top sailplane air show teams also recreated his success.

From an airshow perspective, it proved to be a poor choice, as most viewers had no appreciation of the forces and difficulty, plus, it cost huge altitude investments, and in a sailplane, that was not replaceable. The result was the disappearance of the maneuver in sail plane shows.
 
Gliders can do lateral axis "frisbee" rotations, not so much true end over end tumbles. See 2:30 here. Sometimes "shoulder rolls" are lumped into the tumble category but they are basically just 3D aileron rolls with added rudder and forward stick.

 
geezer said:
It was previously believed that gyroscopic forces were required to produce the 3 axis rolling motion, but he carefully analysed the necessary timing of stick and rudder application, and a Lomcevak resulted. Several of the top sailplane air show teams also recreated his success.

From an airshow perspective, it proved to be a poor choice, as most viewers had no appreciation of the forces and difficulty, plus, it cost huge altitude investments, and in a sailplane, that was not replaceable. The result was the disappearance of the maneuver in sail plane shows.
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nauga said:
Inertial coupling can give you a pretty good end-over-end tumble that looks a lot like a lomcevak, even on airplanes without propellers.

Nauga,
and that guppy magic
Click to expand...
Thanks for the information!
 
Scotty flew a Schweizer SGU 2-22EK, N2790Z from 1966 to 1973 in airshows all over the USA.

If you wish to see his plane, go to the National Air and Space Museum, it is hanging from the ceiling. I suspect that is the ONLY plane in the NASM that I sat in. I found him a fascinating pilot, with amazing skills.

My partners and I bought the Cessna 172 tow plane he had been using in Feb. 1970. We had the prop repitched for better cruise performance, as he had a climb pitch prop for the tow service.

Release from the tow plane was typically at 3,000 feet.

His full name was Byron G. McCray.

Scotty,s airman information shows no change since 1969.
Commercial Pilot, ASEL, ASES, AMEL, Glider, IFR.
 
My recollection is that’s one of the maneuvers that made Bob Hoover famous during WWII...the P-39 was supposedly unrecoverable from tumbling because of it’s mid-mounted engine, and Hoover proved that wrong.
 
Doing one isn’t so bad, it happens so quick you don’t really grasp what just happened. The second one in a row is the gut punch.
 
MauleSkinner said:
My recollection is that’s one of the maneuvers that made Bob Hoover famous during WWII...the P-39 was supposedly unrecoverable from tumbling because of it’s mid-mounted engine, and Hoover proved that wrong.
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Where the engine was located in the fuselage wasn't the issue, it was where the ammo was carried in the nose and the fact that it often wasn't carried and/or was expended in combat, which moved the CG too far aft.

The P-39 had that large, heavy (213 lb) 37mm M4 cannon in the nose along with a 30 round magazine. The M54 rounds it used weighed 2 pounds each. Given that it was mounted in the nose, the absence of the weight of the ammo and the M6 magazine, long witb the absence of the ammo for the two nose mounted .50s had a significant effect on CG. The later M10 cannon used a 58 round disintegrating link belt and that increased the weight shift, in part because it was more reliable.

P-39s used in training initially were flown with no ammo or magazine. That moved the CG aft, and that aft CG created very inconsistent spin recovery traits. Once they started adding ballast in the noses of P-39s used for training missions, the P-39 was more manageable. In combat the M4 cannon with the M6 magazine was notoriously unreliable, firing at most 5 or 6 rounds before it jammed. However, the good news was that the early P-39 models consequently didn't have the same too far aft CG issues in combat.

The aft CG and overall relaxed stability issues combined with very light elevator control forces required a light touch on the stick. Good pilots who were able to fly it to the edge of it's flight envelope liked it's handling. Ham fisted pilots learned all about it's spin recovery characteristics.

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The P-51 Mustang also had serious stability issues when the 90 gallon fuselage tank had any significant amount of fuel in it. As a result pilots would take off and fly on the fuselage tank until it was about 2/3rds empty before switching to the drop tanks on the wing (initially 75 gallon aluminum tanks and later 108 gallon paper tanks or 150 gallon aluminum tanks). Using the fuel in the rear fuselage tank first was essential as they could not maneuver safely with more than about 20-30 gallons of fuel in the fuselage tank.

However using that internal fuel first meant that if the fighters were engaged shortly after crossing the coast in Europe they'd have to drop the external tanks with significant fuel still in them, which curtailed their range and limited their ability to cover bombers closer to the target. Often Luftwaffe fighters would engage P-51s (and P-47s) as early as possible for the sole purpose of getting them to jettison their external fuel tanks while they still held fuel.
 
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