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Supercub Thrust Line

Any modicum of improvement to that rear seat should help the social life. I know it saves on weight but I want full dual landing lights with 4 AeroLed’s so I can score the deer before I hit it on darkish opps.

You forgot the #1 rule of night flying. If you don't like whats in front of you while landing at night then turn the lights off.

Glenn
 
the biggest thing I noticed was the take off. The airplane was ready to fly sooner. This really became apparent when I took off from a gravel bar I had used a week prior with SJ in the back. I had a passenger in the back of similar weight and horsed it off a little earlier than I thought I should and she came off and climbed. That was a surprise as I was expecting a mush. The other thing I noticed was the trim. I no longer need to trim nose down in the landing configuration. It is quite comfortable to slow down and pull flaps and not have to play with the trim. I do not like working against the controls and usually trim for hands off but no longer have to mess with it. In fact the only time I trim now is for a different load. I have heard some people say they lost visibility over the nose but I never really noticed any difference. I know the nose is up a bit higher but I never noticed it from the pilot seat. I am happy with the mod and have yet to find any negative to it. Mark is always great to work with and Super enthusiastic to hear what you think. In my opinion if you truly fly your airplane and strive to get all you can out of it and yourself it is a great modification.

Likewise !!
My first FUBAR with the thrustline was trying to take off in wet sticky snow on skis. When I got to the creek bank and still didn't have flying speed, I figured I was screwed, but I just pulled back and the plane came off and kept going up. that sold me for life. Second thing I noticed, is if you do a lot of high performance turns in a day, it reduces you workload tremendously. the airplane just wants to suck itself around the turn.

Do you need it if you're a sunday go to flyins pilot?? NOPE
 
At 600 rpm idle your prop is still producing thrust.

The thrustline Mod removes some of that downthrust from a stock thrustline.

The stock down thrust must be counteracted by "up stick", which adds weight to the tail which the wing has to carry.

Remove the downthrust and required upstick and the wing loading is less. Simple?!! Airplane flies slower with lower wingloading!
 
Hi fellows,
Having an experimental PA-18 on construction I am having the opportunities to do the right things on it to have a better performance. About trustline questions and link to show answers that didn’t work anymore, anyone can tell me if the time justified it? Is there any drawings showing how to make it?
 
carl,
I don't think you'll find anyone worth their salt giving ya much info on pirating a man's hard work on getting a mod stc'd here to save you money ! sorry just my observation of your comment.
take how ever!!

jr. :-(
 
Hi fellows,
Having an experimental PA-18 on construction I am having the opportunities to do the right things on it to have a better performance. About trustline questions and link to show answers that didn’t work anymore, anyone can tell me if the time justified it? Is there any drawings showing how to make it?

Just call up Thrustline Mark with your credit card handy. $1800 last I checked.
 
carl,
I don't think you'll find anyone worth their salt giving ya much info on pirating a man's hard work on getting a mod stc'd here to save you money ! sorry just my observation of your comment.
take how ever!!

jr. :-(

Jr. Very polite way of putting what I was thinking.


Sent from my iPhone using Tapatalk Pro
 
Hey fellas, no one has answered his first question. He seems to be asking an honest question and notice that he is from a foreign country, Brazil. The second question was answered with Mark's contact information.
 
Jr.
Maybe my english wasn’t clear enough. I never had the idea of pirating any hard work from anyone. What I asked for is if the Trustline had proved it value along the years. My PA-18 clone is being done from the beggining so is better to have a new engine mount with that design.

Carl
 
I think if you read the reports posted here you will realize that it is benificial. If you want help building a zero thrustline mount I would post those questions in the experimental thread and maybe someone has figured out the dimensions. Mark spent over $100K getting this STC. I doubt he is going to give away all his data so others can build their own. Get out the drawing, some parts and a digital level and I bet you can figure it out. Easy for me to write the check and install it.
 
Steve, I really don’t want another mod if I can do engine mount with de 0 degress. Mark deserves all the benefits from his job. Wayne, also has did a new engine mount with that characteristic. So I was thinking if a member from this group coud be done some like that. If you can help me I will appreciate very much.
Thanks

carl.
 
I will make a new engine mount. I don’t have one. This is the idea. Buiding one with 0 degress. If I coudn’t than in the future I will buy Mark’s trustline. Guys, you don’t have idea what is to import something when you aren’t a trader here where I live.
 
I don't want to be the one to ruffle anyone's feathers, but everybody on this site that is building an experimental is robbing ideas from someone. Javron. , Bearhawk etc etc have all gotten their ideas from someone else. Nobody has a problem with people copying piper or atlee or ?????? When they are building an experimental.
Mark has a great product and I have it on both of my airplanes and he rightly deserves all the credit and money for taking the time to get it approved and built. But if I was building an experimental, I would be using every idea I could come up with to build it like I want it.

Good luck on your project Carl. But maybe you should have started the thread in the experiment section, not on Marks thread.

Sent from my E6810 using Tapatalk
 
Thanks S2D. I am not too much expert in dealing with the forum and its particularities and how to do it. I never had the intention to be a pirate of others ideas. Appreciate your tip.
Regards

carl
 
I have a 1945 Tango cub that was my grandfathers that I am restoring for my uncle. I have read through this thread trying to figure out if the Thrustline mod will help our cub at all. It has an O-290-D2 engine and no flaps. Is it worth trying the Thrustline mod? Also trying to get a hold of Mark. Seems his website is down and havent been able to get ahold of him by phone. Anyone know how to get a hold of him?
 
Steve......
Could you explain that last post ?? (Flaps)
E

To use the Thrustline Modification you need flaps and in my opinion the Borer prop to be worthwhile. It isn't going to give you much without flaps except maybe a faster cruise. Biggest thing I noticed is I could pull flaps and get off quicker and it landed different full flaps. Now I am use to it and need more. It's like Crack I guess, the more the get the more you crave. 8)
 
To use the Thrustline Modification you need flaps and in my opinion the Borer prop to be worthwhile. It isn't going to give you much without flaps except maybe a faster cruise. Biggest thing I noticed is I could pull flaps and get off quicker and it landed different full flaps. Now I am use to it and need more. It's like Crack I guess, the more the get the more you crave. 8)
Could I suggest black tar heroin? Maybe doesn’t finish as smooth as crack or contain the fruity notes but millions of junkies can’t be wrong!
 
Have put off doing this forever… Mostly because I’ve had this cub a fair amount of time and it’s always worked just fine…. or at least that’s what we tell ourselves when we don’t have the time or energy to invest in trying something else… DOH
ignorance is bliss I guess…
Put off the pirep mostly because far more qualified people than I have already posted up.


Airplane background;


Run of the mill bushbeater. Been in the barn for 17-18 years, rebuilt in ’02ish. Still never was what you would call ‘one of the good ones’ on the slow end. Then had the opportunity to park under a hailstorm a year or two later and got to recover it again. With the help of some good ole boys from MT, I got it in a ‘known’ jig this time, and was pleasantly surprised with how much that improved the bottom end. Heavy cub with long wings, long prop, long legs, big wheels, metal interior, yada, yada, yada… Not a light weight!


I’m a mediocre cub guy at best, but fly big overweight tailwheel stuff daily, so current and proficient at least.
I didn’t do a whole lot of number measuring stuff, because I knew that either it would do as expected, (I have flown other examples with the TL) and I would be a happy camper, or it would surprise me (in a less than favorable way) in which case I’d know it was time to go back and brush up on my flying skills.


Soo… first impression? Power steering. Turns, climbs, moves around with way less effort. Which is huge if you’re in a long wing, overweight pig, and spend you’re day snatching it around to look at stuff.


My initial landings were what I would call longer, although they would measure shorter. I say that, because unlike many stol guys who typically measure touchdown to stop, I count my real world…. where I really needed to be, and where I actually made it stick. That may come across as condescending, but that’s not the intention, what I’m trying to say, is I have no need to stick it on 18’ in a controlled, paved environment. What I do need, is the knowledge of what I can stick it in to every single time in a constantly changing environment… and I was floating it.


And of course this was a simple case of proficiency in the new configuration. I had flown this airplane for almost two decades set up differently and was pretty intimate with where it paid off, and was now flying a little blind. A few laps at it and I was back to normal distances, and less than an hour later I had shaved more off my norm than I actually expected. I doubt I’ll go in to any tighter spaces than I normally would, I just appreciate the knowledge that I’ve now padded my safety margin. To try and quantify that for inquiring minds, we have several favorite cub haunts that are 250’ - 300’ long, but with good approaches. We have countless perching knobs that make fun stops when the wind is right, that’ll park two airplanes if the second guy in is handy, and of course clear approaches again. I’m almost always 2 up, sometimes with the dog, and always with enough goodies in the back to be self sufficient. Soo… not really what I would call pushing the extremes, but not letting a good cub go barn sour either. That’s fun enough for me.


Take offs? it’s a heavy pig, as cubs go, so not Valdez showstopper material, but if you yank it off early (and I did just to see if we helped there any) it will pull itself off and grunt away a fair amount sooner. I have a 300’ strip on one end of my property, and a 180’ strip on the other. There is NO over run as you will either be in a canal or running in to a levi if you screw the pooch. The levi is 20’ tall, so departing towards the levi means you need to be at 21’ agl by the end of the strip. They are generally crosswind strips, but they make good yardsticks for testing comfort levels. They’re very comfortable set up this way. In no wind it’ll land or take off either way just fine. This all seems very unscientific, but for me at least, it’s much more meaningful, than knowing what a particular airplane could do this in ‘X’ amount of feet, but not knowing, for sure at least, what I could make that airplane do.


Final thoughts? There are a ton of things we say are ‘must do’s’ on these things. But for me at least, a bone stock cub is pretty darned close to perfect, so my list is pretty small. This one definitely fits the ‘must do’ bill for me.




Take care, Rob

 
Hey Rob,
thanks for the real world pirep.
theres been varying reports on effect on cruise speed increase.
have you had an opportunity to compare numbers?
thanks
Doug.
 
As I have said before Mark’s thrustline has saved me from myself more time than I can count. It’s amazing how you can get it to hang there on the edge just enough to clear the fence or creek or washout where before it might bounce into the air but would set you back in for one more bounce. After my Borer prop it’s my favorite mod and my cub like yours Rob is far from the best flying one around.
Glad you like it...
dave
 
Hi dave,

Yes, it pulls itself around a turn that would usually have you 'nursing' it. I know you can relate to that feeling.

Oliver Doug, Sorry I didn't add a speed run, but as I indicated, I know where the needles used to fall, and where we are now. I don't think I saw the 7 -10 mph gain most have reported. I am probably closer to 4-5 mph faster, but I'll take that. I may have a draggier cub than those who saw higher increases. I will say it is quicker to get on the step, so to speak, which for me is far more important than the last couple mph. Less time with it all hanging out...
Take care, Rob
 
The biggest eye opener for me is just what Rob described. The Thrustline mod makes a cub turn like it’s on a rail. It’s a crazy feeling. Almost like it gets sucked around a turn. I gained + or - 4 mph. 7-10 mph seems pretty optimistic unless 8.50s were installed with the Thrustline
 
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I flew mine just before and after and the cub just felt lighter after.
Also about 4 mph faster after
TL mod, vgs, goodyears and borer are all worthwhile upgrades. Quitting snacking after supper is my next upgrade until Catto gets legal.


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