I bought a TT Pro 46 thinking I would get a LT-40 ARF to go with it for my first plane, especially since the LT-40 has a larger wing (more visible) for a 40 size plane. Turns out you can't find the ARFs anywhere, and SIG has no idea on when they will be offering any model of ARF kits again (per their email to me), and I'm not sure I want to build a regular LT-40 kit. So, just so I know all of my ARF options, will the TT Pro 46 work okay with a 60 sized trainer without being underpowered, or do I really need to stick to 40 sized trainers with this engine?

Most .40-.46 size trainers are designed around the lower powered O.S. LA engines.

A typical .40-.46 trainer uses an O.S. .46 LA engine. These produce about 1.2hp if you go by the manufacturer's own ratings.

That is the equivalent of a standard .32 size ABC engine.

The .60 LA ( often used in .60 trainers ) produces about 1.7hp... about the same as most ABC .46 engines... and about the same as your engine!

So go for it!

My best recomendation is don,t do it, instead get a forty sized trainer. The visability issue and differances between the two classes of trainer is not that great.

Using what is intended for the airplane is always the best way to accomplish the mission which in this case is learning how to fly.

John

John is right, you should stay with a size that will work best. There is not anything fun trying to fly a really underpowered plane and it will be much more difficult to learn on as the lack of power will make it
more difficult to recover from your mistakes.

Thanks guys. That helps me out. Better to have too much engine than not enough was what I was thinking also.

I have a NIB SIG <span class="J-JK9eJ-PJVNOc">Kadet</span> Senior and the recommended engines are .29-.40 CU. IN. Glow or .35-45 CU. IN. 4-Stroke. So it looks like your .46 would work in the SIG <span class="J-JK9eJ-PJVNOc">Kadet</span> Senior. I'm sure that youcould find a 60 size trainerthat the manufacturer recommends an engine that is larger than yours. If you want to use your .46 engine you will just need to look for a 60 size that your engine falls in the recommended sizerange. Good luck in your search. I hope it works out for you the way you want it to.

<span class="J-JK9eJ-PJVNOc">rwf</span>

The senior will fly on a 25 but not well. I have a 91 FS on mine!!!!!

The Sig LT-40 kit or ARF is comparable in size to some 60 size airplanes and your TT 46 will fly it well. Your TT 46 would also work in most 60 size trainers. Although performance would be limited... learning to fly on the wing is not such a bad thing. Most flyers learn to fly on the prop by grossly overpowering...which can be fun and also have benefits, but flying on the wing can also teach you to be smoother on the sticks and better teach you the pysics of flight. You can send a concrete block in the air if you have enough power and enough prop(which could be fun), but perhaps you are wanting to fly with some style and grace ?

We have an older guy in one of our clubs that flys a Senior Kadet with an old and rather worn O.S. .40FP
It floats around like a helium filled balloon...
There's just enough power for him to fly it w/ skis in winter.

A TT .46 Pro will fly a Senior Kadet just fine IMO...it will also fly a Hobbico .60 size trainer better than adequitely...BTDT.

A trainer doesn't necessarily need to be over powered...

The Tower trainer for example, with a TT or O.S. .46 AX or similar, can be pretty hot...for a trainer.

just make sure you buy some lead weights...you will need them upfront if you you want a nice flying plane

the TT 46 should power a .60 size trainer ok for scale like flight. A trainer has low wing loading anyway so it'll float nicely with a lighter engine up front. You may need to mount it far out front to balance properly.
You'll need a longer take off run and your landing will be around 1/4 throttle.

I doubt you will be able to do any inside loops since the tt.46 will be pretty asthmatic around 1/2way through the manuevre.
but if you just want to get into the air and float about just build it light enough and think of it as a powered glider.

TT46 with an LT 40 Kadet-very nice setup, probably one of the best. You will have a load of fun even after you get well trained.

A few years back I had an old beat up junky piece of garbage Vmar Stick 60 hanging in the garage without an engine and radio gear. I also had one of those Evolution 46's out of a Hangar 9 trainer my brother had that was sitting on the bench without a home. So I threw some radio equipment in that old stick plane 60 along with that Evolution 46 and flew the remaining life out of that old plane. It would do all the basic manuevers like rolls and loops, but verticle climb was pretty limited. The plane was loaded down with epoxy and anybody familiar with Vmar knows there wood appears to be something other then balsa. Kinda looks like a cottonwood and is total garbage, but I still had a ball flying the old thing even with the smaller then recommended engine.

With all due respect....

... what is "intended" for this plane is a .60LA engine, which produces the same amount of power as a .46 TT ABC engine.

So either will fly the plane as intended.

I never said it would not fly the airplane What I still maintain is its a poor idea if ones goal or mission is learning how the fly.

Also I give very little heed to those imaginary horsepower figures The manufacturer throw out which are always derived using test clubs (props) which are impossibly small and incapable of flying a real world airplane.

In every case of someone doing this I have ever seen or been involved with it always resulted in some disappointment and the lengthening of learning curve.

John

Even if you completely forget about the HP claims, the bottom line is that .60 trainers are designed around lesser engines, and give very good performance with the .60LA style engines.

As such the .46 normally aspirated engines are their equivalents and will fly the plane equally well.

There is no need for the OP to settle for a smaller plane, nor spend his money on a larger engine for his desired trainer. Doing either is a "poor idea".

I've instructed many students on .60 trainers with .60LA engines and NO "disappointment" was involved.

The planes would not prop hang, but otherwise they performed VERY well and were perfectly configured for their intended purposes... to be a trainer.

Given that the .46 ABC style engines produce the same amount of power as a .60LA for which the trainers were designed, it may be a bit disingenuous to suggest that he must upgrade to avoid disappointment.


If anything there is a reason that .60 trainers like this one : [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXGHD4**&P=ML]Click me![/link] , underscore the point and the configuration.

The above trainer is supplied with a .60LA engine.

Ok I don,t beleve it is bad advice to normally engine up somewhere from the midrange of a manufacturers suggestion to the upper end of that range I am sorry you do not agree however that will remain my advice to the original poster and that is certainly not "disingenuous". He can do with it as he will.

I don,t care what you do or how long you have been flying or how many people you have taught I will continue to suggest the above for new folks.

What I will not be be drawn into is a big pointless discussion over manufacturers specs.

I have stated my opinion, it stands and I will not belabor the point in this thread any further Please feel free to trounce all you want.

John

Sig recommends the Avistar .46 2 stroke for their LT-40' The Avistar is one of the highest output .46 size out there, not a .46la. Most 60 size trainers want a powerful .60. FOr instance the Alpha 60 recommends the Evolutiom .61 not a bushed anemic 60 size.
Can you fly a 60 size trainer with a good .46? Sure. Can you learn to fly that way? again, sure but your margin of error is lessened, No room for growth... you'll still need to buy a 60 for anything else you fly in a 60 size ( tiger 60, 4* 60, At-6. etc.) Can you have fun flying a 60 size powered by a .40? If you like flying a kite. Everybody has a Piper cub in their hanger, but how many of those get flown regularly? Very few and only in lazy circles on calm days. The exceptions are the overpowered Cubs which just reinforces my opinion. Put 40s on 40 and 60s on 60s and you'll be just fine
That being said, I'ld rather fly a telemastion giant with a .25 even if I had to throw it off a cliff than not fly anytrhing! Have fun!!!

I'd just get a .40 Tower Trainer. Good plane at a good price, then save your money for a radio or fuel/accessories. IMO, most trainers are all pretty much the same.

ive flown the tower trainer rtf (training a club member on one) w/ a tower .46 and it is so overpowered its crazy. for basic training purposes we fly around at 1/4 throttle with a 11x5 apc prop, the plane floats along like a trainer should. i see no reason why a .46 engine with a 12x4 or 12.25x3.75 wouldnt fly a .60 trainer well enough to get the person out of trouble if they need too. you would prob only get 50 feet of vertical if u went strait up but at an angle you should be fine.

what i would do is decide what u would rather buy, you could buy the .60 sized plane and if the engine isnt enough buy an engine as well and save the .40 for something else. or just buy the .40 sized plane

if you really want a .60 plane then get the .60 and try the .46

Get a Kadet Senior (or the World Models clone if Sig doesn't have it), it will fly fine with a BB .40 engine, your TT .46 is actually oversized. And with a 78 inch wingspan it's plenty visible.

Exactly.

The .60LA is in the "upper" range for most .60 high wing trainers, as is the .46LA for most .40-.46 trainers.

Manufacturing specs have nothing to do with this, rather that the .60LA is about the equivalent of a TT .46 ABN in terms of ACTUAL power ( actually the latter is a tad more powerful with the right tuning and prop.

So either could be used on the .60 trainer with very good results and as the plane itself is designed for.

I recently flew a .60 trainer someone brought out with a .40 FX engine in it. I was surprised at how well it performed, albeit with a lower pitch prop just as Jimmy suggests, for more thrust with less speed... making it a very good combination for the newbie.


A low wing more aerobatic plane would be a different kettle of fish altogether.

If you allready own the tt46 and you like the idea of the larger 60 size Trainer. All I am saing is that yes the TT46 will fly most 60 size trainers adequately. I train new members as well and I would not refuse to train someone with that setup. It would serve the purpose fine. However...as other posters have pointed out...sometimes a bit more grunt can be a good thing, but I was just trying to make the point that you could get by with that setup just fine if you allready have that engine laying around not getting used. Use what you got so you can save money to go towards that new Jett 50 engine to mount on a Quickie 500 plane! Then you will really show them at the field who isn't the slow pokeLOL

I can highly recommend the Global RCM 40 Trainer with the TT Pro-46 engine to be a good match and a solid ARF with better flying qualities than an LT-40.


The .46 engine may fly a .60 size trainer, but you'll likely have to add weight to make up for the lighter engine and so it's a double-whammy. Less power hauling additional weight. On a grass field it may be hard to get airborn, but one there it will fly. Aerobatics will suffer, though. My first attempt at powered flight was with the minimum recommended engine on a Sig Kadet MkII (a .25). It was a disaster as it had to be hand launched.

They still have LT-40s at Nitroplanes. It is the same plane that you would have bought from SIG, just "misdirected".

I learned to fly on my PT-40 trainer with an Aviastar 53 but later changed to just an Irvine .40. I found the extra power of the .53 was just wasted on the trainer. Admittedly the Irvine is a premium engine but it doesnt make the power of a .53. So Idont believe in overpowering a trainer, it may get you out of trouble quicker but it can also get you into trouble a lot faster. Just my opinion based on my personal experience.
I think the Tower Trainer 40 MKII ARF is a good quality kit and the price is excellent. Ihave not flown mine but the build quality looks good.
A light .60 size trainer with a stout Thunder Tiger 46 should work pretty good depending on the weight.