VG's..........which are the best ones???
Thinking of installing VG's on my PA-18-150........which ones are the best.....the ones from Cub Crafters or the other ones........???? Can't remember there name.
This always starts a fight on the other chat site. For the money I would go with the Micro VG's instead of the BLR (Cub Crafters) ones. The BLR strake is ugly and in the way when using the lift handles. The safety factor they are advertised to provide has to do with the "Moose stall". The Moose stall is caused by a steep uncoordinated turn. The square fuselage skidding sidways through the air, blankets hoizonal stabilizer causing the tail to stall. My hunting partner has the Micros and said the only thing he noticed was more aileron authority, ie less movement in the stick to get results. The draw back is frost removal, wing covers on and off, and they occasionally fall off (one here, one there) and have to be replaced. Here again with any mod you have to weigh benefit verses the draw backs and expense. Crash
I put the BLR VG's(Cub Crafters) on my bird. I like the Micro setup for the tail better than the big BLR strakes, but they do not bother me and are not that hard to work around. I would say that if your expecting to see a big performance difference save your money. I would not go as far as to say don't by them because one day you may end up needing the extra margin of safety they could provide, but I am saying the money could be better spent elsewhere.
Just an opinion!
Check out this big long thread on VGs. It helped me buy my micros which I think were well worth the money.
I have owned a set of the early Micro-Aerodynamics VG's and installed many of the later version (VG's under the horizontal stab) of The Micro-A VG's on customers' airplanes that I am welcomed to fly. I also fly a set of BLR VG's on my father's airplane.
I can state emphatically that there was LITTLE detectable difference between the latter kits. (late MICRO/BLR).
We could talk all day about VG's and not change any opionions. Some guys would even say to leave them off and spend the money on gas.
I like the improved low speed aileron authority afforded by VG's, PERIOD. !!
I also like a good value for the money.
Get some and glue 'em on!
I have a set of the micros with the row on the horizontal stabilizer. I would have to second David's comments and add just two things.
1) If you like a definitive warning preceding the stall, you wont get much of one. This is because the stall becomes more of a mush than a good break. This can be good and bad. The cub really is pretty docile in a straightforward power off/on stall anyway and the VG?s make it more so. Bad thing is if your hanging right at the bottom trying to go really short on a landing, it's much harder to feel when the thing is going to payoff.
2) I fly a nose heavy 180HP and before the VG's had a hard time 3 pointing because I couldn't get the tail down. The row of VG's on the horizontal stabilizer made a big difference in adding the extra control to the elevator.
I'd say go with the Micro's they work as good and are much cheaper!
I put the BLR's on about 2 yrs ago and still am amazed at the enhanced performance they provide. Just today I had made a couple of tight one-way landings and was very happy that I had the VG's. Coming back from the lodge, I went to about 1,000 agl and slowed the plane up to 25 mph indicated with power on just to practice feeling for the edge. You can hang it at 25 and just reduce power and let her mush down from altitude about like a helicopter. The trick is adding power back in to flare with, which eats up some runway. I agree that the extended gear will help when landing and taking off in the high nose attitude required to effectively utilized the VG's. That's next on my wish list.
I also have a 17 year-old son that flies my PA-18 and the VG's give me a little more peace of mind when he's out tooling around. You'd really have to try hard to stall and spin the plane with them installed. I wouldn't be without them. As for the difference between them and the Micros, I can't comment.
Murph, pretty much my experience with Micro's also. With nearly full power, you can hold altitude at 10mph indicated, sure there is a little shudder now and then and I would not want to approach at that attitude, but it is fun to do.
Also, went out and did about 10 spins in it on Friday the 13th. It will spin with the VGs brielfy, but it becomes a spiral dive pretty quick and airspeed gains rapidly. The best ones were "flown in" with a little power, can't really get it going good without it. One turn is still pretty quick, but there is no "snap" to it like the non-vg spin.
I am looking at them for the 170 I just bought also. A little more pricey for that bird, but they made such a difference on the cub.
Vgs came on the cub I got from CC, flew one pretty much the same for several years prior, doing the same thing, low and slow, the only time the balls in the center is when its moving from one side to the other. The old plane would break on me once in a while, haven't had the new one break in two years. The elevator is more responsive with the strakes at lower airspeeds. The vgs on the tail work just as good according to reports. They didn't come with the first kits, but guys have retro-fitted both.
When the vgs first came out for the cub, all the oldtimers poo-poed them. The next year they all showed up in the field sans leading edge cuffs and drooping wing tips, and sported vgs.
A former student made some from plastic angle for his Kitfox. He reported the stall speed droped 11mph, but the best result was he could no longer spin it. He says that the Kitfox has a bad tendancy to spin if attempting to slip or even slightly cross-controlled, several accidents caused from this. Now he can slip to his hearts content, which is good, the Kitfox uses flaperons and they suck. No aliron control with flaps extended. He copied the pattern from my cub, but started playing around with them after the initail flight ( the advantage of an experimental certificate) and said placement didn't seem to matter, just having them on helped.
What kind of power and flap settings are you guys using to get down to those indicated airspeeds? Is that straight and level or is it a climb?
I have been wondering for some time why I can't get down to those airspeeds! In straight and level, to hold my altitude, takes somewhere around 15-1700 rpm. That is with full or nearly full fuel and myself weighing 205 pounds. I have squared off wings, droop tips, and BLR VG's. My airspeed indicator reads 3-5mph faster than actual. Even considering that I get a good buffet at 50-55 indicated clean and 40-45 with full flaps!!! Compared to some of you that seems high.
MD, Crash, etc... any ideas? Could it be a rigging issue? Is this normal?
Different airspeed indications in different planes means nothing, every Cub reads differently. My airspeed reads 0 when I'm slow, hanging on the prop (fresh O/H on the gauge), some read high, some might be close. You need to learn to fly by feel, rather than looking at a gauge when operating really slow.
To Bottom Gun I would say that I hope your ASI tells you that you're cruising faster as well, though the reading at stall could be greatly affected by angle of attack.
Of course, Mark's right, you need to be flying by the seat of your pants.
I'm thinking about one of them new foam seats from FineLine Interiors, maybe my butt being awake will help my low speed flying skills.
You said your airplane has squared-off wings with droop tips. Is that squared off at the last full aileron rib, or extended, with droop tips.
If it's just squared off at the last full aileron rib, you have cheated yourself out of some wing area. I've seen a couple done like that around here and it ain't a pretty sight. These ones aren't sporting any droop tips, though.
I think there's a neato angle of attach gauge described with photos for the hard of reading on this very website.
What angle of attack are you stalling at?
Hi. I guess I have a comment/question. The Micro kit was designed to provide increased performance on landing and ( takeoff ) at maximum weight. Actually somewhat over maximum weight as some are flown. On climb out when you feel like you are balancing the Cub on the head of a pin, they are designed to help just as much in this attitude as in landing. But I never see any comments on this phase of flight. Comments? Jerry.
As far as I'm concerned, Jerry, you're the man with all the good answers. So, I'm surprised that you are asking this question. Maybe it's more of a comment?
To comment and maybe answer/discuss the topic of climb-out...
I believe that the VG's provide a margin of safety by allowing the airflow to stay attached at much higher angles-of-attack. This margin can be realized and explored whether flying slow on landing OR takeoff, as well as in a turn.
The nature of most of my operations right now doesn't require me to execute maximum performance climb-outs, like some may require.
Maybe the guys operating on the edge of climb-out performance can comment.
That "head of a pin" feeling is definitely a regime that I, for one, could use more practice at. It's no longer a common occurence in my flying.
I may not be the worlds greatest cub pilot, but I have the confidence that I can fly it pretty well.
Why do you assume that because I ask about airspeed questions I can't fly my cub by feel?
I understand that high angles of attack will cause inaccurate asi readings but its seems that they would read lower than mormal, as is the case with these other post.
Let me be clear, I was just wondering if most cubs stall out in the same airspeed neighborhood? I know many of you have tons of cub experience, the same way I have more than some, but I don't know it all and neither do any of you. The only way to gain experience and be a better cub pilot is to ask questions, right? Isn't that what this website is all about.
I enjoy reading and posting on this site, but if I want an "examiner" to critique my flying I will invite you down here.
p.s. my wings are extended two rib widths past the stock aileron end.
Lance, wait a second.
I didn't get the impression that anyone was saying you're a bad driver.
I certainly wasn't. I simply agree that we can do a better job af flying by using our proprioreception(feel) than by reading a gauge which may, or may not be accurate.
I understand that you're comparing the performance of your Cub to that of others by inquiring into airspeeds on the gauge at certain flight regimes.
By the way, what does that Cub weigh? Is the wing rigged with proper wash-out and dihedral?
Some guys have talked about reducing the twist in order to gain an efficiency advantage, but I think it a bad idea. I have learned that the tip needs to continue flying (while the root stalls) and that is more important than a 1/2% lift increase gained by eliminating washout.
The dihedral in the Cubs is already so slight that I can't imagine an efficiency gain by eliminating that as well.
The flying quality realized by proper washout (trailing edge twisted higher at the tip than at the root) is of greater importance to me than the performance and handling gained by even VG installation. I'm not saying that you are saying anything about what I just wrote.
Lighten up BG Lance. I'd rather come and examine you and tell you you're an idiot to your face, than type it on the computer. That's what the "rant and rave" forum is about.
No offense. Dave Calkins.
PS I know some guys that own more than one airplane and don't care about flying any of them well. As long as the thing looks good on the ground they're happy. You hafta accept some ribbing in the weeding-out of the "flakes" and those who care to continue learning. Please write back on the weight/rigging issues? I'm interested in what guys think a "light Cub" wieghs, too.
Jeez Lance, lighten up! All I meant was that no two ASI's in Cubs ever seem to indicate the same stall speeds. David is right, if you think your stall speed is high, check rigging, and lighten up your Cub too. I don't want to offend your flying knowledge, but I'm sure you know that the higher your landing weight, the higher the stall speed.
Does anybody know if its legal to mail a puppy from California to Louisiana?
Lance , is there anybody else in your area that has a cub you can fly next to and compare indicated speeds and fly next to each other and see who can fly the slowest. When its hot out my airspeed will indicate down to zero but when its cold it stalls at 35 indicated with power in level flight ( not climbing). Stock wing with Micro vgs.
A friend of mine has wings just like yours with plane booster tips and micro vgs. Before I put my vgs on we flew next to each other to see who could fly the slowest. I couldnt come close to flying as slow as he was. I put on the Micro vgs and tried it again and we both could fly the same speed on the slow end. I think I was flying a hair slower but he wouldnt admit it.
A few weeks ago we were giving rides out of a hay field at 6100 MSL on a 70 degree day and I was using alot more distance to take off at pretty much the same weight. We both have 160 hp and 44 pitch props. Looked to me like the long wing works alot better at altitude.
Bottom Gun.....I'd strongly suggest you have your airspeed indicator checked........any shop that does pitot/static checks can check it......and only takes a few mintues to do. Also......if you hae a GPS....you can check/verify airpeed that way also. I agree with you.........only way to get an answer is to ask questions..............keep asking........I know I do..............my mother always said....if one doesn't have anything nice to say.....then don't say anything at all..........just a thought for all of us to ponder. Anyway.......hope you get your airspeed indictor problem worked out...........oh ya..........as a Flight Instructor with 30 plus years of instructing...............the most important instrument in an airplane is also the biggest............................that big windshield in front of us and what we see out of it. .....we all spend to much time inside....................looking at GPS's......and other insturments..............Happy Flying "Brian"
I want a puppy.
Something like a Rottweiler. They are SSSOOOO manly to be seen walking with.
Just joking, Rotties are a great breed, if you can get past the dirty looks from all the Yuppies with their Golden retrievers.
OOps, sorry to offend you Golden lovers.
Maybe an Austrailian Shepherd...no, already have one of those. She's too damn smart and gives me dirty looks when I make her wait on the float before she can climb in.
Standard Poodle, Yeah!
Cavy, how's that new 18?
Wow, Bottom Gun! YOu must have got the same increase in insurance, letter from the IRS, raise in Gas bill as I did! I hope you are not offended by my post either? I learned a lot from Anne, and some of the others in reference to the Rant and Rave section??? My main interest in this site is "learning" from others "experience". and then comparing them to my own. I like to BS like most others but when it comes to cubs and their real performance, most posts are "over exagerated". Jerry Burr and a few others have actually done test! "some" of the guys in Alaska have been building and flying cubs into the real world of "on the edge flying" and some of us have been humbled (wrecked a few) and live to share, learn and explore new ideas. As for ASI, they are notoriusly in accurate at higher angles of attack due to the location of the Pitot/static ports on the strut! I can tell you this, I have a Helicopter ASI that was initially set up by a shop in my plane and once on final it is only a "REFERENCE" POINT, PERIOD!! I fly all approaches by feel (thousands of hours IN A CUB) FEEL!! I use my GPS groundspeed read out that compaired to the last (stable ASI read out gives me the best sense of what the wind and plane is doing to my approach.
Thanks for the questions, and frankly I have little regard for most "CFI's that didn't learn and continue to fly (light, stick and rudder planes) to check me out on anything other then current regulations!! But I am always learning from those around me (EVEN IF ALL I LEARN IS WHAT I SAY TENDS TO PISS SOME PEOPLE OFF) even if I am accurate!
Have a nice day!
By the way CAVY I love my German Shepard, and the Rat Dog we have!
Some twisted thoughts on twisted wings and things. The names and places have been changed to protect anyone. If anyone were cruising in a Cub with flat wings, the entire wing would be working as one unit. Developing equal lift from tip to tip. Sans wingtip vortex ect. If anyone were to slow down to - steep turn - land - check rack points - and they lowered 4 degrees of flaps, they would have twice the recommended ammount of wing twist. Two notches of flaps are OK. Four are great.
The Cub hasn't read any of the important Federal publications concerning root stall. Therefore the entire Cub wing aft of the front spar is stalled before the wing actually breaks in the stall. The wing root is actually the third area to develop stall not the first.
Flat wings are not a good idea for most people, especially no flap Cubs. But they are not Voodo either. This tape will probably self destruct after you have read it. Jerry. :evilbat:
Jerry, can you give us some pros and cons to the idea of a wing rigged without twist.
Most of the factory airplanes I can think of were certificated sporting washout, and some include that little "stall strip" glued a bit out from the root.
Are there some things to think about other than the "textbook" ideas?
I understand that changing the camber (applying flap) to a portion of the wing will increase that portion of the wing's angle of attack.
Bottom Gun Question
Bottom Gun: All of the indicated airspeeds claimed, you have to take with a grain of salt. When the plane is at anything but almost straight and level flight the pitot tube is not getting a straight shot of air down it to pressurize the airspeed indicator as calibrated. High angles of attack really throw it off. I can fly for miles with mine reading zero mph with full flaps and power, nose pointing at the sky. The only way to get a correct reading is to use a gps in calm conditions or run the test on two directions and average the two.
I found that I had an air leak in the line going from the pitot tube to the airspeed indicator that made mine read off. There are several rubber hoses connecting the tubing together that are places for a leak. Pull the hose off the airspeed indicator and use an air chuck to pressureize (30lbs) the hose while plugging the pitot tube end. It should hold 30 lbs of pressure. When you pull the air chuck off the hose it should blow back some air. You can hear it leaking also if it is. Crash
More twisted thoughts.
*WARNING* The information in the following text is not legal or recommended. It could be hazardous to your health. With that out of the way. Let's say you have an object 6 feet wide and 16 feet long. You want to lift this object. You measure 14 stations along the length of this object. You place 14 jacks at these stations along the centerline of the object. (it is the strongest point) The object weighs 14 tons and each jack will lift 1 ton. With the jacks parallel they will lift the object. However it was difficult to balance the object in this manner and some people were being injured if the object accidently fell off the jacks. The people who oversee safety decided that to be safe the end jacks would have to be canted two degrees from each other, and the remaining jacks canted in a linear manner to make a smooth transitition between the end jacks. Therefore no two jacks would lift in the same plain. Someone with limited balancing experience could lift the object safely. The problem was that with no two jacks lifting the same direction the object could no longer be lifted. The 14 jacks could only lift 13 tons. The solution was to add two more jacks at new stations 15 and 16. Success. Everyone could lift safely and everyone was happy. Except a few people who had no problem balancing the object with the jacks parallel. So they returned their jacks to parallel and found that with the additional jacks they could lift an additional two tons which made them very happy. These objects are usually used in pairs, which form a device. They found that when these modified devices were used in cruise mode they would (because of the additional lift) cruise faster thus farther on the same ammount of energy. It is assumed that these modified devices will not be loaned to or used by people that do not have a fair ammount of balancing time. Jerry.
I like your style Jerry! :microwave: (This is my favorite smiley, so I figured I would use it despite the fact it really has nothing to do with the post I just wrote. I just like to see the little guy blow up!)
The alternative method of deciding what works and what doesn't?
subscribe to all the journels and magazines available, sit around the bar/campfire, or airport lounge and discuss it with all your mechanic friends. Offer the STC holder, manufacture, or dealer of the latest wiz bang to install the widget on a customers plane, Install it on the most vocal of the groups airplane, He loves it (of course) cause he is first! He tells all the guys he hangs with and 1/10th of them have you install it on their plane, and now you have a bigger mouthpiece for the widget!! after about 2 years, there are more stories, lies, over exaggerations, and a few wrecks to discuss than you can keep up with (you being the the installing mechanic) So you just nod your head and say (must work!)
Then a guy like Jerry comes along and actualy does the testing with all the widgets, disproves the value of most, and gives honest performance statistics for the all of the combinations available to him for testing and we are back where we started.
If you keep it light, as close to the design as the original engineers intended you will likely get pretty acceptable results. ORRRRRR you can add power, more wing, VG's leading edge cuffs, Fuel scanners, bigger/softer tires, pretty paint, new wing tips, huge flaps, extended ailerons and so forth and we will keep the circle going for ever!
Benifit: we will never run out of things to talk about on the Web site, bar room, campfire, pilots lounge, hanger, livingroom!
Sounds good to me!
How much faster would these modified devices be in cruise, and how scary would they be with no flaps, if the operator had plenty of experiance.
Hi Tim. If you look on the application worksheet put out by the Alaskan arm of the FAA, to get approval on Tundra tires. You will see that one of the first things the inspector must check, is to see if there is twist in the wings. I can't imagine why. Jerry.
Yes, more lifting. But 21.4286% ?, assuming the additional 2 tons were added to the original 14 ton configuration, not the 13 ton limited experience device?
Yes, of course it will cruise faster without the opposing forces (trailing edge up there dragging). But how much?
Can you quantify the performance improvements on a Cub wing sans washout?
Can you fly that Cub into and out of that sheep strip at gross, with turbulent air, a sore foot, and a duct tape fabric repair from your client walking under the wing with his rifle slung over the shoulder, etc., etc., ad nauseum?
I know that at least one of my maintenance customers SHOULD stay away from the advanced version of the rigging procedure.
I'd like to know if maybe all of us should, or if the benefits are simply getting off the ground 7.6799 feet earlier than our buddies from the Gulp-Can-I impromptu stol contest when leaving the AIRPORT on a nice day for an expensive burger.
Jerry, for the real world, how much performance gain?
Should one sporting the untwisted wing consider what turbulent air does to the lifting surfaces. (Low, slow, unstable, gusty, wife and kid in the back, it might be nice to have some of that wing flying in a slightly different angle, and stalling slightly later than the rest of it does). OOPS, head of a pin feeling coming back.
Maybe I answered my own question. I spend my time in many endeavors and am very good at nearly all I attempt. When it comes to flinging my body off the ground on a hangglider or paraglider, or jumping a snowmachine off a cornice, or attempting a double back loop on the windsurfer, or attempting to skip my motorcycle across 50 feet of water, or pulling my dog, fighting over a bone, off another dog.....a half-notch of caution and planning will make the difference between getting old or just being bold.
Is there enough extra lift and speed in an untwisted Cub wing to get me to pull myself out of the ranks of wannabe's and be a b?
I think I'll just b Dave Calkins.
But thanks, Jerry, for the creative writing.
Hi Dave. I don't like to repeat myself. But!. Flat wings are illegal. I am not recommending it. I never have. It is ironic that Alcohol is listed as a poison. Go figure. Jerry.
Thank you, Jerry.
I still am curious if there are any performance gain numbers from the EXPERIMENTAL rigging procedure that we may, or may not have been discussing earlier.
I am still in learning mode.
PS are you saying that consumption of the poison, alcohol, is a bad thing?
Will enough of this behavior affect my life? Is it possible that I am stupid enough to do such a thing, even having been warned?
Funny how we have the gub'ment to keep us safe when a little natural selection would have taken care of it long ago. (no I am not an evolutionist)
I had an experience of coming around a snowy, downhill curve in a road marked "NO SLEDDING" and nearly creaming 2 toddlers set in a sled occupying one lane, with the vehicle of the parents occupying the other lane. I decelerated enough to avoid the tragedy this might have been. It was at night and dark. The one parent stood over the sled with that "deer in the headlights" look, unable to move, though there was probably 4 seconds of time to slide the kids out of harms way, AND LET ME THROUGH. Natural selection!!!!! But I would have been a killer.
Yep, we need to be warned of everything that we can't think of on our own. We may still insist on going forward with it.
Enough of this rave.
How 'bout those numbers?Thanks
Please read my posts in the Sick Bay, under rigging. Where am I going wrong in my thinking? I know the cord line drops with flaps "inducing" washout, but I thought the flapped wing section, having a different airfoil, high press air spilling through the slot, ect., would then have a lower stall speed? What if I'm not smart enough to drop a notch of flaps before pulling a tight turn over that rack? Personal experience is that twisted wings just have a better "feel", able to ride closer to the stall safely, than a flat wing. This could all just be in my head, I know perseption is not always reality, I could be very wrong, but it works for me. A flat wing may help cruise speed, but I really don't care, If I want to fly somewhere fast, it won't be in a Cub. Does a meer 2.5 degrees of angle across a wing really decrease lift that much? Is the increase in lift really worth the decrease in safety? No matter how many thousands of hours of "balancing" time are written in my log books, I will always consider myself a student pilot, willing to learn. I find the attitude of, "Good pilots don't need the safety measures" train of thought disturbing. When the Cub is loaded heavy, and the wind is gusting from the wrong direction, and the controls are being slammed from stop to stop to hold it in line with a tight strip, I want every safety measure that a student pilot can have on a Cub. But like I said, I could be wrong, I am willing to learn, and you probably know more about Cub wings in flight than anyone. Call it experimental rigging, or a big board with jacks if you have to, or send me a PM, but if I am wrong in my thinking, please let me know.
Thanks: I got it !!
Anyone reading this needs to know that Jerry is a good guy.
I'm sure that there is a point here other than..."hey, if you can lift the 16 ton flat thing with 16 jacks, do it, if not, you ain't got the skill".
I am very interested in this.
Anyone out there not interested in maintaining their certificated a/c in accordance to the FAR's (that means in accordance with manufacturer's recommendations and to the type certificated and/or supplemental type certificated condition), please certify the thing as EXPERIMENTAL so that my mom doesn't wonder why I put my family in one of those dangerous Piper Cubs, after you kill yourself. There are good reasons for all the FAR's. One is that what you fly has certain "flying qualities". If it ain't maintained to it's type-certificated or STC'ed condition, you're breaking the law and endangering the passtime that I'm sure you feel priviliged to take part in.
Let us learn from one another.
Soooooo, let's say we just rig the wings like Mr. Piper thought best. I think we started here talking about which VGs are best. Well, now that I think I'll put Micro's on - - - - is there anyplace to get a better than regular price? or do I just pay my 695$ and be happy?