Van's Air Force
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RV-12 vs Rans s-19
- Thread starter elfiero
- Start date
westexflyboy
Active Member
Build Time, etc.
The drawings look good for the S-19, and perhaps it will look good in 3 dimensions some time next year when they finally finish the prototype.
S-19 advantages include more fuel, wing tanks, and sliding canopy.
RV-12 advantages include better visibility than any other low wing tractor, far easier to build than any other all-metal airplane, and should be one of the fastest LSA based on wing area. Sonex is faster but I wouldn't fit.
I'm still holding out for the RV-12.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
The drawings look good for the S-19, and perhaps it will look good in 3 dimensions some time next year when they finally finish the prototype.
S-19 advantages include more fuel, wing tanks, and sliding canopy.
RV-12 advantages include better visibility than any other low wing tractor, far easier to build than any other all-metal airplane, and should be one of the fastest LSA based on wing area. Sonex is faster but I wouldn't fit.
I'm still holding out for the RV-12.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
otterhunter2
Active Member
I think the S-19 is going to be one tough bird! Plus it has some of the features which I find a little more appealing. Now the RV-12 is flying so Vans has the lead but we will see. Both are excellent examples of the future of affordable flying. 
http://www.rans.com/S19Const/Structural testing/S19StructuralTestingThumbs.htm#
http://www.rans.com/S19Const/Structural testing/S19StructuralTestingThumbs.htm#
Mike Armstrong
Well Known Member
I agree, the S-19 looks absolutely bulletproof. I'm hoping for a side by side comparison in the LSA Mall at Osh this year.
http://www.rans.com/3S19.htm
http://www.rans.com/3S19.htm
The S-19 looks a lot better than the RV12 and has a castoring nosewheel so hopefully does not have the handbrake thingy. Really don't like that idea.
Cost wise, I'd expect Vans to come in a lot lower than this kit. Kit and layout looks nicely done.
Due to Van's rep in the market, I expect a lot more RV12s will be sold than S-19s. Another metal design choice is nice to have however..
Cost wise, I'd expect Vans to come in a lot lower than this kit. Kit and layout looks nicely done.
Due to Van's rep in the market, I expect a lot more RV12s will be sold than S-19s. Another metal design choice is nice to have however..
grantcarruthers
Well Known Member
As I am just finishing the emp on my 8 I gotta say that stabilator looks yummy and easy as pie to build vs a horz stab, 2 elevators and the blessed trim tab.
Whats on the 12 tail, elevators or stabilator??
Whats on the 12 tail, elevators or stabilator??
otterhunter2
Active Member
The things that make you go Hmmmmm!!! A Lycoming in a S-19, well, well.
Quote "The S-19 is powered by a ROTAX 912 ULS engine producing 100 HP. The engine has proven itself reliable in years of operation. Other engine options will be explored, from Jabiru to Lycoming. The aircraft seats two in side by side in a 43.5? wide cockpit. Headroom is ample for even 6?4? pilots, and even larger with slight modifications" Unquote
Quote "The S-19 is powered by a ROTAX 912 ULS engine producing 100 HP. The engine has proven itself reliable in years of operation. Other engine options will be explored, from Jabiru to Lycoming. The aircraft seats two in side by side in a 43.5? wide cockpit. Headroom is ample for even 6?4? pilots, and even larger with slight modifications" Unquote
grantcarruthers
Well Known Member
Never mind, just found a pic, same thing. Stabilator and trim tabs for both -12 and -19
It appears that Vans is taking a more hands on approach to the LSA plane. Easier to build, i.e. , flaperons, hand brakes etc. Actually I find the hand brake on the stick interesting. What I don't like is the fuel tank in the cockpit area ... much rather have it in the wing. The build would be easier somewhat with the single tank. The S19 looks very nice, but will most likely be heavier than the Vans.
sprucemoose
Well Known Member
RV-12/ S-19 observations
Am I missing something? Looking at the drawing of the S-19 and the pictures of the 12, they sure look an awful lot alike. I'd wager most people couldn't tell them apart at 50 feet.
Chase, I'm curious why you consider the sliding canopy and wing tanks to be advantages? The tip-up canopy makes ingress and out-gress easier, and the fuse-mounted tank makes the folding wings possible. Since LSAs tend to be aimed at older, medical-less pilots who are less dexterous, I think the advantage is to the tipper. If you're young and spry, then the bigger, wing tanks might be an advantage, but then again, the young and spry are not the target market for the RV-12.
And Mike, I wouldn't hold your breath. If you had only one prototype to display, would you put it at the LSA mall, or right in front of your tent?
Am I missing something? Looking at the drawing of the S-19 and the pictures of the 12, they sure look an awful lot alike. I'd wager most people couldn't tell them apart at 50 feet.
Chase, I'm curious why you consider the sliding canopy and wing tanks to be advantages? The tip-up canopy makes ingress and out-gress easier, and the fuse-mounted tank makes the folding wings possible. Since LSAs tend to be aimed at older, medical-less pilots who are less dexterous, I think the advantage is to the tipper. If you're young and spry, then the bigger, wing tanks might be an advantage, but then again, the young and spry are not the target market for the RV-12.
And Mike, I wouldn't hold your breath. If you had only one prototype to display, would you put it at the LSA mall, or right in front of your tent?
westexflyboy
Active Member
Fuse tanks, canopies
Fuselage tanks bother me in terms of crash suvivability. Not enough to stop me from buying the RV-12, but still, I don't want to be soaked in gasoline from a busted fuel tank if I have to land in rough country. RV-12 wings are removable, not foldable. Neither option really appeals to me, because I have removed wings from an airplane before. It's not something I would want to do very often.
Both slider and tip-up canopy options have their advantages or appeal. There is an entire thread dedicated to that endless debate elsewhere on this site. There does not appear to be an option for either the RV-12 or S-19. So... If you want a tip-up, you have to go with Vans. If you want a slider, you have to go with Rans.
While older pilots are certainly a segment of the LSA market, I don't think they're the only target. Sport Pilot is also about increasing new pilot starts. I pitch Sport Pilot to all new pilots.
The market will decide all these topics in time.
Chase Snodgrass
Presidio, Texas
http://flybigbend.com
Fuselage tanks bother me in terms of crash suvivability. Not enough to stop me from buying the RV-12, but still, I don't want to be soaked in gasoline from a busted fuel tank if I have to land in rough country. RV-12 wings are removable, not foldable. Neither option really appeals to me, because I have removed wings from an airplane before. It's not something I would want to do very often.
Both slider and tip-up canopy options have their advantages or appeal. There is an entire thread dedicated to that endless debate elsewhere on this site. There does not appear to be an option for either the RV-12 or S-19. So... If you want a tip-up, you have to go with Vans. If you want a slider, you have to go with Rans.
While older pilots are certainly a segment of the LSA market, I don't think they're the only target. Sport Pilot is also about increasing new pilot starts. I pitch Sport Pilot to all new pilots.
The market will decide all these topics in time.
Chase Snodgrass
Presidio, Texas
http://flybigbend.com
sprucemoose said:
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Mike Armstrong
Well Known Member
Hi Jeff,
"Am I missing something? Looking at the drawing of the S-19 and the pictures of the 12, they sure look an awful lot alike. I'd wager most people couldn't tell them apart at 50 feet."
Its definitely hard to tell what the S-19 is going to look like until one is actually built, but I'm betting you will indeed be able to tell them apart at even a '100ft' or more.
"Chase, I'm curious why you consider the sliding canopy and wing tanks to be advantages? The tip-up canopy makes ingress and out-gress easier, and the fuse-mounted tank makes the folding wings possible. Since LSAs tend to be aimed at older, medical-less pilots who are less dexterous, I think the advantage is to the tipper. If you're young and spry, then the bigger, wing tanks might be an advantage, but then again, the young and spry are not the target market for the RV-12."
I like the slider because I like the availability of an open cockpit whether going sightseeing low and slow or on a hot tarmac while taxiing. Also the wings on the -12 do not fold (that is, until they start getting built they are removable as is the wings on the -19, though more difficult to do. I like the idea of the fuel tank out of the cockpit area in case of a crash, nah, make that 'way' out of the cockpit area.
"And Mike, I wouldn't hold your breath. If you had only one prototype to display, would you put it at the LSA mall, or right in front of your tent?"
Yup, I agree with you on that one. That first shiny prototype is gonna be in the same place as the -12 was, showing off next to the company tent.
Mike
"Am I missing something? Looking at the drawing of the S-19 and the pictures of the 12, they sure look an awful lot alike. I'd wager most people couldn't tell them apart at 50 feet."
Its definitely hard to tell what the S-19 is going to look like until one is actually built, but I'm betting you will indeed be able to tell them apart at even a '100ft' or more.
"Chase, I'm curious why you consider the sliding canopy and wing tanks to be advantages? The tip-up canopy makes ingress and out-gress easier, and the fuse-mounted tank makes the folding wings possible. Since LSAs tend to be aimed at older, medical-less pilots who are less dexterous, I think the advantage is to the tipper. If you're young and spry, then the bigger, wing tanks might be an advantage, but then again, the young and spry are not the target market for the RV-12."
I like the slider because I like the availability of an open cockpit whether going sightseeing low and slow or on a hot tarmac while taxiing. Also the wings on the -12 do not fold (that is, until they start getting built
they are removable as is the wings on the -19, though more difficult to do. I like the idea of the fuel tank out of the cockpit area in case of a crash, nah, make that 'way' out of the cockpit area. "And Mike, I wouldn't hold your breath. If you had only one prototype to display, would you put it at the LSA mall, or right in front of your tent?"
Yup, I agree with you on that one. That first shiny prototype is gonna be in the same place as the -12 was, showing off next to the company tent.
Mike
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I've been patiently waiting for the RV-12 but, now I'm not so sure. The S-19 just looks so much more like a real airplane as compared to the '12.
1. I'll never be comfortable twisting any aircraft engine to 5000+ rpm- ever. Continental and Lycoming make nice little engines(around 100 hp) that will live almost forever without the silly gearcase. The S-19 was originally designed around a O-235 ( I called and asked).
2. No differential braking and a bicycle handle to boot? Talk about a step backward.........
3. What happens when you crash land? A. everything in front of you gets squished. B. Everything behind you squishes you. Do you really want it to be a gas tank???
4. Removable wings sounds like a good idea until you've done it a few times- 'nuff said.
Yea, the S-19 is going to cost more to build but, so far it looks like a much better deal in the long run. But maybe I'm wrong
1. I'll never be comfortable twisting any aircraft engine to 5000+ rpm- ever. Continental and Lycoming make nice little engines(around 100 hp) that will live almost forever without the silly gearcase. The S-19 was originally designed around a O-235 ( I called and asked).
2. No differential braking and a bicycle handle to boot? Talk about a step backward.........
3. What happens when you crash land? A. everything in front of you gets squished. B. Everything behind you squishes you. Do you really want it to be a gas tank???
4. Removable wings sounds like a good idea until you've done it a few times- 'nuff said.
Yea, the S-19 is going to cost more to build but, so far it looks like a much better deal in the long run. But maybe I'm wrong
the_other_dougreeves
Well Known Member
Don't worry and just let the Rotax run. It is a proven engine with a good (although not perfect) service record. It makes a happy song about 5200 RPM and will make 75% power there all day, sipping 5 gal/hr or MoGas or 100LL. Yes, the gearbox is new and different and not in use on the average Lyc / TCM motor. However, the same was once true of things like fuel injection and electronic ignition.elfiero said:
Two questions immeadiately come to mind.
1. Can anyone name another application where an internal combustion engine buzzes along at or above 5000rpm for hours on end every time you use it for 20+ years? any small displacement conventional aircraft engine lasts that long at 2500 rpm with relatively little maintanence.
2. Can you pick up used jugs or ignition components at just about anyplace you can land for a Rotex?
1. Can anyone name another application where an internal combustion engine buzzes along at or above 5000rpm for hours on end every time you use it for 20+ years? any small displacement conventional aircraft engine lasts that long at 2500 rpm with relatively little maintanence.
2. Can you pick up used jugs or ignition components at just about anyplace you can land for a Rotex?
westexflyboy
Active Member
Engine weight and S-19
I once read the statement of an aeronautical engineer that listed the three most important aspects of aircraft design are:
1. Weight
2. Weight
3. Weight
The Rotax 912 is the principle reason we are able to enjoy excellent performance from the new breed of Light Sport Aircraft. I agree there's a lot to be said for tried and true, but if you install a Lycoming or Continental, most of that performance margin will be lost. In my opinion, if you want a Lycoming, you should forget Sport Pilot rules and go straight to the standard RV's. You're going to bust the LSA weight restriction if you fly with two average American men behind a Lycoming or Continental. On the other hand, I have owned two 912's, and trust them even over very harsh terrain. Wonderful engine that is already well proven, whether you have personal experience or not.
Also, I just received a reply from Rans concerning matched hole construction for the S-19. Almost the entire airframe is matched hole, so build time should be near identical to RV-12. Seems it's mostly a matter of picking the features you require when choosing between the two.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
I once read the statement of an aeronautical engineer that listed the three most important aspects of aircraft design are:
1. Weight
2. Weight
3. Weight
The Rotax 912 is the principle reason we are able to enjoy excellent performance from the new breed of Light Sport Aircraft. I agree there's a lot to be said for tried and true, but if you install a Lycoming or Continental, most of that performance margin will be lost. In my opinion, if you want a Lycoming, you should forget Sport Pilot rules and go straight to the standard RV's. You're going to bust the LSA weight restriction if you fly with two average American men behind a Lycoming or Continental. On the other hand, I have owned two 912's, and trust them even over very harsh terrain. Wonderful engine that is already well proven, whether you have personal experience or not.
Also, I just received a reply from Rans concerning matched hole construction for the S-19. Almost the entire airframe is matched hole, so build time should be near identical to RV-12. Seems it's mostly a matter of picking the features you require when choosing between the two.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
the_other_dougreeves
Well Known Member
Yes! Motorcycles, boats, snowmobiles, spec racecars (e.g., Formula Mazda, where the engines are sealed and often go several years before rebuilds), etc. The issue isn't the RPM - witness F1 cars, who get 20,000 RPM out of their 2.4l V8s - but how the engine is designed. Rotax seems to have done their engineering correctly.elfiero said:
No. This is somewhat of a problem, but not a huge one. Let me try and explain:elfiero said:
When parts fail, they are usually small ones. As you suggest, the (dual) ignition boxes and voltage regulators used on the 912 sometimes fail. They are made by Ducati and can be FedExed from many, many locations overnight (might even find one at your local Ducati dealer - I did this with a CT guy last month).
If you have a failure of a large part - cylinder, gearbox - it's not going to be in stock at Podunk Muni's local A&P. However, if I blow a cylinder in a O-320, am I likely to get the engine fixed that day or the next? Chances are that the repair is going to take a while. IMHO, the availability of such big ticket parts isn't such a deal.
What is the bigger problem is to find A&Ps who will work on the Rotax and learning about the engine yourself. Syncing the carbs is a PITA, but once you learn how to do it, it's not that hard.
The Rotax is not perfect. It is a viable engine for LSA and, as others have noted, very light. However, it is more complex than the O-200. Nothing is perfect, but we (some of us anyway) live in America, and we have a choice
The 5000 rpm thing always scares people used to traditional aircraft engines but this is relatively meaningless when an engine is designed to run there. The stroke on the 912 is only 61mm so the piston speed is well within reasonable, conservative limits. Similar small displacement fours are run in Europe on the Autobahn and Autostrada at 5000+ rpm continuously with excellent life and reliability.
These engines are very light as has been stated. I can easily lift one myself.
Van's and other designers chose this engine because they are proven, fairly available and reliable. The small Lycos and Contis are way heavier.
While Rotax is behind on deliveries because of the recent demand, most parts can be obtained from many dealers in North America by overnight Fedex. Rotax is making a big effort to train more people in repair and servicing of their powerplants.
These engines are very light as has been stated. I can easily lift one myself.
Van's and other designers chose this engine because they are proven, fairly available and reliable. The small Lycos and Contis are way heavier.
While Rotax is behind on deliveries because of the recent demand, most parts can be obtained from many dealers in North America by overnight Fedex. Rotax is making a big effort to train more people in repair and servicing of their powerplants.
hevansrv7a
Well Known Member
performance
OK, I, too, am getting old and may someday need to go LSA to keep flying, so I read this stuff avidly. That said, 128 mph on 5 gph is no biggie. I'll bet my -7A can do better (I know I can do 115 on 4.3).
OK, I, too, am getting old and may someday need to go LSA to keep flying, so I read this stuff avidly. That said, 128 mph on 5 gph is no biggie. I'll bet my -7A can do better (I know I can do 115 on 4.3).
Geico266
Well Known Member
Not only is the small piston size a factor, the length of stroke is short and conducive to high RPM's. Trust me, the Rotax 912 & 912s are bred for high RPM and long service life. The sweet spot is 5,200 is any 912 I've owned. I know of several 912's with over 2,000 hours on them and the compressions are like new. In fact taking a compression check on the 912 I had was useless, it was 80/80 after 450 hours.
How do they do it? One reason the clyinder walls are "ceramic" coated. Wear is minimal when the correct oil is used, and the engine is serviced properly. The tolorances are very close. This is a tight, well engineered engine, with a long history of dependable service.
The gear boxes do require period shimming to maintain "tightness". This is a non-event and can be done with basic hand tools and a hand gear press. Slop in a gear box is a bad thing with a prop on the other end.
Don't be afraid of the Rotax engine. Study them, learn about them, take a Rotax repair or maintenance course and see first hand, and up close the quality that goes into these engines. You will not be disapointed.
They are the right choice for LSA. Van's himself picked the Rotax 912 series for the RV-12.
Ran's has always used Rotax engines in all of their other kit built planes. Frankly, I am very surprized they even looked at a Lycoming or Continential power plant for their S19. If I remember right there is over an 70 pound penalty for wanting an 0200.
How do they do it? One reason the clyinder walls are "ceramic" coated. Wear is minimal when the correct oil is used, and the engine is serviced properly. The tolorances are very close. This is a tight, well engineered engine, with a long history of dependable service.
The gear boxes do require period shimming to maintain "tightness". This is a non-event and can be done with basic hand tools and a hand gear press. Slop in a gear box is a bad thing with a prop on the other end.
Don't be afraid of the Rotax engine. Study them, learn about them, take a Rotax repair or maintenance course and see first hand, and up close the quality that goes into these engines. You will not be disapointed.
They are the right choice for LSA. Van's himself picked the Rotax 912 series for the RV-12.
Ran's has always used Rotax engines in all of their other kit built planes. Frankly, I am very surprized they even looked at a Lycoming or Continential power plant for their S19. If I remember right there is over an 70 pound penalty for wanting an 0200.
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Geico266 said:
Actually the cylinders are "Gilnisil" nee Nikasil plated . Porsche and many bike engines have used this for years. The rings wear rather than the cylinders. A lot cheaper to replace rings. The aluminum cylinders reject heat much faster than a steel cylinder and are much lighter, plus they are properly attached to the block via tension studs, not base bolted. If you burn mogas, you can use Mobil 1 and it would be doubtful to measure any wear on most sliding surfaces in 1500 hours.
Keeping the idle up over 1750 rpm makes the redrive gears last a lot longer. Many people not used to these engines idle them way too low and beat the gears to death.
I don't really like the dry sump system. Why, why would they do this? Heavier, bulkier and their suction system is potentially scary for cold weather ops- no scavenge stage either. Jabiru did this better with a wet sump. Pre-heat is recommended. And of course the twin carbs. They work but are dated.
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gmcjetpilot
Well Known Member
The RV community rules
Has the Rans S-19 flown? What is the specs. My guess is it may be nice but my money is on the RV12 flying: a little faster, carry a little more, a little further, off of shorter runways. Could be wrong, but if you want a RV12 or S-19 than by golly build it. You do know the company support and community you get with the RV product. I am sure Rans is a good company, but unless they have one flying than I would wait. It looks heavier and draggier. Regardless of spec, until they build it and fly it than its a guess.
Has the Rans S-19 flown? What is the specs. My guess is it may be nice but my money is on the RV12 flying: a little faster, carry a little more, a little further, off of shorter runways. Could be wrong, but if you want a RV12 or S-19 than by golly build it. You do know the company support and community you get with the RV product. I am sure Rans is a good company, but unless they have one flying than I would wait. It looks heavier and draggier. Regardless of spec, until they build it and fly it than its a guess.
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Yes, I fully understand the Rotex is a "completely engineered powerplant system" and when it has been around as long as the continental "c" series, I'll have a great respect for it. But just like todays cars, the average joe might as well not even open the hood 'cause there's nothing for you to do under there anyways. The "real aircraft engines" can be modified for more HP relatively easily and cheaply as compared to the rotex which is basiclly impossible to change and is producing the maximum HP it can ever produce when you take it out of the box. Also, is it even possible to hang an electriclly operated prop on a rotex? I don't think that silly gearbox would like that very much. What if the all important "factory" exhaust won't fit your particular setup? I've heard that if you mess with the pipes the "little engine that could" don't like it much. I guess I'm just one of those A&Ps that won't accept the french/canadian motor until it gets rammed down my throat. If you really want to understand it, take a vacation in quebec and see how you're treated as an American- it'll give you a whole new outlook on this little engine.
otterhunter2
Active Member
Welcome to the world of the Canadian split personality!! Enjoy the diversity and take the flak as most Anglo-Canadians do or for that matter all non-Franco cultured individuals do! LOL
elfiero said:Yes, I fully understand the Rotex is a "completely engineered powerplant system" and when it has been around as long as the continental "c" series, I'll have a great respect for it. But just like todays cars, the average joe might as well not even open the hood 'cause there's nothing for you to do under there anyways. The "real aircraft engines" can be modified for more HP relatively easily and cheaply as compared to the rotex which is basiclly impossible to change and is producing the maximum HP it can ever produce when you take it out of the box. Also, is it even possible to hang an electriclly operated prop on a rotex? I don't think that silly gearbox would like that very much. What if the all important "factory" exhaust won't fit your particular setup? I've heard that if you mess with the pipes the "little engine that could" don't like it much. I guess I'm just one of those A&Ps that won't accept the french/canadian motor until it gets rammed down my throat. If you really want to understand it, take a vacation in quebec and see how you're treated as an American- it'll give you a whole new outlook on this little engine.
Any engine can be modded for more power. The Rotax is no exception. More stuff coming down the pipeline already. The 912 has capability for manual, electric and hydraulic props already. It has provision to drive a vacuum pump off the rear of the redrive housing also. Rotax has a pipe kit which includes all parts to fit the exhaust to your airframe. Ahhh this engine is designed and built in Austria, you know that right? Bombardier just owns them.
If you really want to understand the engine, Rotech Research in beautiful Vernon, BC offers all types of training courses. Some coming up in March and April.
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Mike Armstrong
Well Known Member
gmcjetpilot said:
Good points, agreed.
But, in final configuration and ready to sell, side by side at the Osh LSA Mall, most folks will give into looks, not specs, as their final decision maker on which of these two aircraft to buy. In that respect, I'm gonna say the S-19 will have the edge. I honestly hope not, but thats my prediction.
the_other_dougreeves
Well Known Member
I urge you spend a few hours looking at and getting to know the engine. It is uncomplicated and easy to work on. There are few maintenance requirements, and the most complicated system is the dual carbs - they need to have the throttle travel adjusted periodically. This is checked using a pair of vacuum gauges.elfiero said:
Electric and hydraulic (oil) CS props are in use in many applications (e.g.,, 80Hp DA20-A1 Katana, T-51 Mustang). USA LSA regs require FP props, so we don't see them here as much.
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I think Rotax was addressing the maintenance issues in the design of these engines. They wanted to avoid opening up the engine between majors so used hydraulic lifters, Nimonic exhaust valves, Nikasil coated cylinders, water cooled heads to keep the hot spots well below any temperatures (300F max) which would cause long term cracking.
Anything that might have to be checked like oil, filter, fuel pump, coolant, spark plugs, ignition components are right at hand. Valve covers can be removed by taking off one central socket head cap screw per head. Rubber parts like hoses are renewed every 5 years. Not too bad.
Anything that might have to be checked like oil, filter, fuel pump, coolant, spark plugs, ignition components are right at hand. Valve covers can be removed by taking off one central socket head cap screw per head. Rubber parts like hoses are renewed every 5 years. Not too bad.
gmcjetpilot
Well Known Member
Don't get me started
Yes you can make more power but its already turning 6 or 7 grand. THERE AIN'T NO REPLACEMENT FOR DISPLACEMENT. Thankfully we have the O200, IO240 TCM and O235 Lyc. Sadly LSA has a stupid, NOT thought out or politically set weight limit. And what is with a top speed limit? What the pilot can handle 130 mph but not 140 mph or 150 mph top speed? No HP limit?
Unfortunately due to the idiotic artificial Euro induced random (yes random) max gross limit for the LSA, the extra 50 lbs for the American power plants is hard to swallow, with the very limited max gross weight allowed.
Frankly I almost guarantee in the real world LSA's with two people even with a Rotax will be OVER max legal gross. LSA regulations are almost like ROTAX wrote them. Where did ROTAX come from, originally Europe and now part of Bombardier (French/Canada), WeeeeeeWeeeee. Now they have LSA approved two strokes! TWO STORKES!
Unlike our RV's or experimental, we can stuff a O235 to a IO540 in and ignore weight (which is a bad idea but we can and people do). The LSA has a hard weight limit. There for the O200 or IO240 is barely in the ball park. The O235 is a tad more than the TCM.
The LSA limit should be 1500 lbs, not what 1350 lbs. I don't think 150 lbs more gross is a big deal and it would open the door to the TCM and Lyc, which in my opinion would be a slam dunk choice over the Rotax, not withstanding the lighter weight advantage. It would also open the door to more certified planes covered under the LSA banner. Hummm the LSA category really seems more political than practical to me. It bad enough we have to use the the WX abbreviation of "FU" for smoke, from the French word fum?e (foo-may). Notice: English is the official international and aviation language.
Other strikes against the Rotax in no particular order:
With all due respect it's only 74 cubic-inch engine. It is, as was said, maxed out. There is only so much you can do with so few CUBES.rv6ejguy said:
Yes you can make more power but its already turning 6 or 7 grand. THERE AIN'T NO REPLACEMENT FOR DISPLACEMENT. Thankfully we have the O200, IO240 TCM and O235 Lyc. Sadly LSA has a stupid, NOT thought out or politically set weight limit. And what is with a top speed limit? What the pilot can handle 130 mph but not 140 mph or 150 mph top speed? No HP limit?
Unfortunately due to the idiotic artificial Euro induced random (yes random) max gross limit for the LSA, the extra 50 lbs for the American power plants is hard to swallow, with the very limited max gross weight allowed.
Frankly I almost guarantee in the real world LSA's with two people even with a Rotax will be OVER max legal gross. LSA regulations are almost like ROTAX wrote them. Where did ROTAX come from, originally Europe and now part of Bombardier (French/Canada), WeeeeeeWeeeee. Now they have LSA approved two strokes! TWO STORKES!
Unlike our RV's or experimental, we can stuff a O235 to a IO540 in and ignore weight (which is a bad idea but we can and people do). The LSA has a hard weight limit. There for the O200 or IO240 is barely in the ball park. The O235 is a tad more than the TCM.
The LSA limit should be 1500 lbs, not what 1350 lbs. I don't think 150 lbs more gross is a big deal and it would open the door to the TCM and Lyc, which in my opinion would be a slam dunk choice over the Rotax, not withstanding the lighter weight advantage. It would also open the door to more certified planes covered under the LSA banner. Hummm the LSA category really seems more political than practical to me. It bad enough we have to use the the WX abbreviation of "FU" for smoke, from the French word fum?e (foo-may). Notice: English is the official international and aviation language.
Other strikes against the Rotax in no particular order:
Single ignition?
It has a gear box
It is not made in America
It sounds like a lawn mower
Cost to overhaul is very high (ie no bargain)
Cost to purchase is as much or more then a TCM or Lyc
Service, parts & maintenance is few-N-far between (comparatively)
It has a gear box
It is not made in America
It sounds like a lawn mower
Cost to overhaul is very high (ie no bargain)
Cost to purchase is as much or more then a TCM or Lyc
Service, parts & maintenance is few-N-far between (comparatively)
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JimLogajan
Active Member
gmcjetpilot said:
Strictly speaking, "Single ignition" is a strike against you since the Rotax 912 is a dual ignition engine.
gmcjetpilot
Well Known Member
YOU
Thanks for the correction, but not sure what a STRIKE is. Does that mean my opinion or other points are not correct? If I get two more?
To repeat myself, I think in the 100-115 hp engine range, the O200 is a far better engine than the Rotax. I am going to guess that the tiny Rotax turns you on. To each his own.
I put a question mark after it, and "a strike against YOU" is kind of personal and not really productive. What does that mean? I make mistakes and I'm wrong all the time. I guess I was thinking of the Subaru. Oh-oops, my mistake, never mind.JimLogajan said:
Thanks for the correction, but not sure what a STRIKE is. Does that mean my opinion or other points are not correct? If I get two more?
To repeat myself, I think in the 100-115 hp engine range, the O200 is a far better engine than the Rotax. I am going to guess that the tiny Rotax turns you on. To each his own.
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the_other_dougreeves
Well Known Member
As noted elsewhere, the 912S uses dual electronic ignition with dual lighting coils built into the alternator (no battery necessary). Also, max continuous RPM is 5500.gmcjetpilot said:
More displacement does not guarantee reliability. Witness the number of Nextel Cup "stock" car engines that blow vs F1 engines. Both are naturally aspirated V8s that make about 800Hp. F1 cars are 2.4L - "cup" cars are 5.9L.
Yes, there is not much growth potential in the 912S to go beyond 100Hp without turbocharging (in which case it becomes a 914). Not a big deal, IMHO.
Geico266
Well Known Member
rv6ejguy said:
Sorry, I could not remember the cylinder coating name and called it "ceramic" as a general term. You are correct, wear is VERY minimal.
The dry oil sump is alittle different, but a benifit is to lower the coweling profile by placing the oil tank on the firewall. Less profile, less drag. Changing oil is a snap. Hand prop until the oil is pushed into the oil container (it gurgles air when all the oil is in the tank) and take the container off & dump it, clean it, reinstall.
Balancing the carbs is really a non issue. Most of the time any inbalance is hard to detect and caused by component wear and breakin. A simple motor cycle carb balancer makes short work of it. Another benifit of the carbs is the are self adjusting to altitude. No more leaning!
Another benifit for cold country pilots is HOT CAB HEAT! You can block off the radiator and send the hot water to a heater core & 12V fan in the cab that will roast you! Toasty warm to 0F!
Cost of overhaul? after 2,500 hours alot of Rotax 912s are still running fine, but since a new one costs $15K you just replace it with a new one and sell the core for $5K or more. Over haul a 0-200 costs?
Fuel savings? 2,000 hours of mogas burning 5 GPH = 10,000 gallons of fuel, average savings per gallon over 100LL approx $1.5 = $15,000. You just paid for your new engine. With the proposed $.75 tax coming on 100LL you might want to put a calculator to that too.
I owned a Sting with a 912s with an electric prop.
Talk to pilots who fly Rotax 912's, study them, learn about them, make a decision and build.
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gmcjetpilot
Well Known Member
Good points, but the weight limit is a bummer
As far as car racing I don't know how we can compare. I watch NASCAR and IRL and they all blow engines. The age old debate about more RPM being harder on the engine is not a debate in mind. A big displacement engine running at lower RPM well below its max potential is going to be more reliable and longer lived, at least in my opinion. However "more reliable" is a broad term. Also if the engine is designed to run at 6,000 rpm than its not an issue. The Rotax is designed for high RPM and has the water cooling, which is nice in a light weight package. No argument. However the air cooled engine is simpler.
I use to ride and watch Tail and Motocross, but not for some time. However I just caught some pro races on TV. They are ALL four strokes! I knew it was going that way. I owned a XL250 Honda (4 stroke) trail bike 20 years ago, but the pros still road 2-stroke at that time. The day of those high RPM two stokes are gone. I saw some very first early Super Cross races in the LA coliseum in the early 70's. I remember the blue two stroke smoke filled the place. Now with the LSA and the low weight we almost need to go to two strokes? Some two strokes are getting LSA approval. TWO STROKES ARE NOT AS RELIABLE AS 4 STROKES IN PLANES. Ask any ultra light guy. Why is Rotax top of the line four stroke. I would not fly two stroke powered plane on a bet.
A Lycoming at 6,000 rpm would basically blow up. Score one for the Rotax. However the Rotax has baby food jar sized pistons verses the Lyc has Large Coffee can pistons. They are different concepts, designed and guided by unique sets of rules. Neither is better but different. Each with its own advantages. The Rotax clearly is making more power per pound (but not by much, and in fact the IO240 is very close to equal HP/Lb ratio).
Could the TCM O200 or IO240 do better. Sure. The O200 in race planes makes at least +150 HP (some 170 hp I have been told) and with light weight exotic parts could be lighter, composite sump and oil tank, titanium parts replace steel and so on.
Again another 50, 100 or 150 lbs to the LSA weight limit would cut into Rotax's business. I think the weight was made to cut out certified planes. WHY? Politics?
My frustration is not with ROTAX, they make a product and it's fine. However LSA is a purposefully limited class of planes in both Weight and Speed. I think a little more weight (to include traditional engines) and a HP limit instead of a SPEED limit makes more sense. That would have been better for the category but not better for Rotax. You can only go so fast on 100 hp, right? The LSA class is about making it MORE draggy, not less. One company makes a clean airframe and leaves wheel pants off to make it go slower? WHAT! That is not progress. I know LSA's will be FAT and FAST past their FAR limits. How are they going to regulate that?
If limit HP you limit speed. This drives better airframes. Who cares if the plane can go 130 mph or 150 mph. I can see a max stall speed, that is a safety issue. However there is a limit to how low HP can go. You can reduce drag and add lift, but you still need HP to climb. A two place plane needs some pony's to lift the payload.
I think this class will languish for years. I laugh at the +30 manufactures of LSA planes, most from Eastern Europe with American front companies. It is like LSA was written just for their planes. The nicest LSA to me is the American Cub (made in Washington State), but cost the better part of $100,000 and it's not fast. So much for cheap flying. The idea of going cross country in a LSA is kind of marginal in the western US or mountainous states (max 10,000 msl for LSA). In America we have a big country that needs more range and pay load than in Europe.
As far as Miles Per Gallon, I doubt many LSA's can hold a candle or beat a (I)O235/O320, RV-9. Why? Because you takea RV9 and fly at 130 mph you will almost make fuel. I think van played around with max endurance speed and he was down to 2 or 3 gal an hour.
I am for progress, but this LSA class is not progress to me, just different. You still need to be fully healthy to fly a LSA, and what disqualifies you to fly as a Private is the same for a LSA pilot. Self certifying allows you to "cheat" I guess, since all you need is a drivers licence. My state just went to 8 year auto licenses and you only need a pulse to get one. Not a real indicator of health. If you can get a LSA certificate you can get a Private in my opinion.
Why would you build a RV12 when you can build a RV8/7/9, which have more performance and can be build for less (used O235, O290, O320). The less desirable Conical mount narrow deck 150 hp O320 can be had for WAY LESS than a ROTAX, way less. Now you have a 150hp RV-9 that can GO fast and if you want, fly at 130 mph and use fuel like moped.
Look ALL good points and not bashing Rotax. My only point, which I do think is valid, the LSA weight limit is restrictive to the point it limits the useful engines you can use to basically the smaller (lighter) Rotax. That is frustrating. Also low powered planes are not safer. On "press day" at AOPA a Press official pilot, flying a new LSA solo crashed because it did not get out of ground effect. I think the engine was down on power. You need all those cylinders.the_other_dougreeves said:
As far as car racing I don't know how we can compare. I watch NASCAR and IRL and they all blow engines. The age old debate about more RPM being harder on the engine is not a debate in mind. A big displacement engine running at lower RPM well below its max potential is going to be more reliable and longer lived, at least in my opinion. However "more reliable" is a broad term. Also if the engine is designed to run at 6,000 rpm than its not an issue. The Rotax is designed for high RPM and has the water cooling, which is nice in a light weight package. No argument. However the air cooled engine is simpler.
I use to ride and watch Tail and Motocross, but not for some time. However I just caught some pro races on TV. They are ALL four strokes! I knew it was going that way. I owned a XL250 Honda (4 stroke) trail bike 20 years ago, but the pros still road 2-stroke at that time. The day of those high RPM two stokes are gone. I saw some very first early Super Cross races in the LA coliseum in the early 70's. I remember the blue two stroke smoke filled the place. Now with the LSA and the low weight we almost need to go to two strokes? Some two strokes are getting LSA approval. TWO STROKES ARE NOT AS RELIABLE AS 4 STROKES IN PLANES. Ask any ultra light guy. Why is Rotax top of the line four stroke. I would not fly two stroke powered plane on a bet.
A Lycoming at 6,000 rpm would basically blow up. Score one for the Rotax. However the Rotax has baby food jar sized pistons verses the Lyc has Large Coffee can pistons. They are different concepts, designed and guided by unique sets of rules. Neither is better but different. Each with its own advantages. The Rotax clearly is making more power per pound (but not by much, and in fact the IO240 is very close to equal HP/Lb ratio).
Could the TCM O200 or IO240 do better. Sure. The O200 in race planes makes at least +150 HP (some 170 hp I have been told) and with light weight exotic parts could be lighter, composite sump and oil tank, titanium parts replace steel and so on.
Again another 50, 100 or 150 lbs to the LSA weight limit would cut into Rotax's business. I think the weight was made to cut out certified planes. WHY? Politics?
My frustration is not with ROTAX, they make a product and it's fine. However LSA is a purposefully limited class of planes in both Weight and Speed. I think a little more weight (to include traditional engines) and a HP limit instead of a SPEED limit makes more sense. That would have been better for the category but not better for Rotax. You can only go so fast on 100 hp, right? The LSA class is about making it MORE draggy, not less. One company makes a clean airframe and leaves wheel pants off to make it go slower? WHAT! That is not progress. I know LSA's will be FAT and FAST past their FAR limits. How are they going to regulate that?
If limit HP you limit speed. This drives better airframes. Who cares if the plane can go 130 mph or 150 mph. I can see a max stall speed, that is a safety issue. However there is a limit to how low HP can go. You can reduce drag and add lift, but you still need HP to climb. A two place plane needs some pony's to lift the payload.
I think this class will languish for years. I laugh at the +30 manufactures of LSA planes, most from Eastern Europe with American front companies. It is like LSA was written just for their planes. The nicest LSA to me is the American Cub (made in Washington State), but cost the better part of $100,000 and it's not fast. So much for cheap flying. The idea of going cross country in a LSA is kind of marginal in the western US or mountainous states (max 10,000 msl for LSA). In America we have a big country that needs more range and pay load than in Europe.
As far as Miles Per Gallon, I doubt many LSA's can hold a candle or beat a (I)O235/O320, RV-9. Why? Because you takea RV9 and fly at 130 mph you will almost make fuel. I think van played around with max endurance speed and he was down to 2 or 3 gal an hour.
I am for progress, but this LSA class is not progress to me, just different. You still need to be fully healthy to fly a LSA, and what disqualifies you to fly as a Private is the same for a LSA pilot. Self certifying allows you to "cheat" I guess, since all you need is a drivers licence. My state just went to 8 year auto licenses and you only need a pulse to get one. Not a real indicator of health. If you can get a LSA certificate you can get a Private in my opinion.
Why would you build a RV12 when you can build a RV8/7/9, which have more performance and can be build for less (used O235, O290, O320). The less desirable Conical mount narrow deck 150 hp O320 can be had for WAY LESS than a ROTAX, way less. Now you have a 150hp RV-9 that can GO fast and if you want, fly at 130 mph and use fuel like moped.
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JimLogajan
Active Member
gmcjetpilot said:
The only engine in that HP range that I like is the Jabiru 3300.
the_other_dougreeves
Well Known Member
I agree - the 600kg / 1,320 lb LSA limit effectives limits you to the Rotax and maybe Jabiru engines.gmcjetpilot said:
Actually, one of the neat things about the 912 is the combination of water and air cooling. Heads are water cooled, cylinders air cooled. If you loose the coolant loop, you can still use partial power for some time without overheating. You can still shock cool a 912, but it's harder to do with the water cooling.gmcjetpilot said:
Most LSA aren't that aerodynamic, I agree - there's just not a huge need for make the airframe slippery if you're limited to 120kt. However, if you use the 2-blade prop adjusted to 5500 RPM in cruise (or use a adjustable pitch prop), the CT makes 130kt on 5 to 5.5gph. Shame we can't do that in the US - guess we might hurt our little fingies.gmcjetpilot said:
Two words: No medical. If you don't have one (or don't want to renew because you think you'll get denied), then all the performance in the world doesn't matter.gmcjetpilot said:
westexflyboy
Active Member
RV EZ-build
From the performance perspective, I absolutely agree. From the builder perspective, my intuition says the RV-12 will have a much higher completion rate. In other words RV-12 will be a heck of a lot easier to build and, for many builders, will be flying months to years sooner with acceptable performance concessions.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
gmcjetpilot said:
From the performance perspective, I absolutely agree. From the builder perspective, my intuition says the RV-12 will have a much higher completion rate. In other words RV-12 will be a heck of a lot easier to build and, for many builders, will be flying months to years sooner with acceptable performance concessions.
Chase Snodgrass
Presidio, TX
http://flybigbend.com
Phyrcooler
Well Known Member
Dittowestexflyboy said:
Which is why I am considering an RV-12 as apposed to an RV-9. I don't want to start a 5 year RV project at this point in my life - but hope to be able to crank out an RV-12 or something comparable in about 18 months.
I agree that for the same money a 7, 8 or 9 with a low hp lyc is the ticket versus the 12. The amount of work is a lot more than a LSA however, and that is the snag.
If Vans could make the quick build 7,8 or 9 a bit "quicker" it may well become very viable to go the above route. Surely there must be some meat in the 51% rule to allow more work done by the factory.
Lets be honest, apart from the few out there ,the majority wants a quicker build .
Maybe all in favour could sign a petition begging Vans to push the 51% rule to its limits. I would gladly pay extra to get me in the air faster. O yes , my 7 is flying but it sure would be nice to quickly build a 8.
EJ
If Vans could make the quick build 7,8 or 9 a bit "quicker" it may well become very viable to go the above route. Surely there must be some meat in the 51% rule to allow more work done by the factory.
Lets be honest, apart from the few out there ,the majority wants a quicker build .
Maybe all in favour could sign a petition begging Vans to push the 51% rule to its limits. I would gladly pay extra to get me in the air faster. O yes , my 7 is flying but it sure would be nice to quickly build a 8.
Phyrcooler
Well Known Member
ABSOLUTELYrv72004 said:If Vans could make the quick build 7,8 or 9 a bit "quicker" it may well become very viable to go the above route. Surely there must be some meat in the 51% rule to allow more work done by the factory.
Lets be honest, apart from the few out there ,the majority wants a quicker build .
Maybe all in favour could sign a petition begging Vans to push the 51% rule to its limits. I would gladly pay extra to get me in the air faster. O yes , my 7 is flying but it sure would be nice to quickly build a 8.EJ
This whole situtation is so complicated! I agree that some group or company had their hand in the rediculously low gross weight limit. I think we should all harass the FAA until they raise the weight limit to 1600. There is no reason a RV9 without wheel pants, VGs, and a O-235 shouldn't be legal!! I guess this is the reason I haven't pulled the trigger and bought anything yet- maybe things will change...............
Oh good, a flame thread
Interesting debates:
Lycoming/Continental vs. Rotax
1320 pounds vs 1500 pounds
120 kts vs 123 kts
The one thing that most of you are overlooking is that Sport Pilot wasn't designed for YOU. The intent of the Sport Pilot rating and LSA is to get more people - people without prior knowledge of aviation - into aviation.
Joe/Jane Average doesn't have an alliance to a particular engine manufacturer (chances are they've heard of Rotax, not Lycoming), doesn't care about the 10 kts because 120 already sounds real fast, and really doesn't care about how things have always been done - because for them it's ALL new.
They just want to do a little flying without having to get a second mortgage. And 30 hours of flying to get a license sounds a lot easier than 50 to 80 hours. Sport Pilot is the path of least resistance. And that's a good thing.
If you are participating in this conversation, consider yourself part of the lunatic-fringe of aviation. We care about everything - even the things that we shouldn't.
Most people that buy an LSA will use the same criteria that they use to buy a car; looks, value, economy, performance and a strong recommendation from a friend.
If they ever see this thread, or ones like it - they will be sure to stay clear of aviation. Because according to us, there is something wrong with everything.
Interesting debates:
Lycoming/Continental vs. Rotax
1320 pounds vs 1500 pounds
120 kts vs 123 kts
The one thing that most of you are overlooking is that Sport Pilot wasn't designed for YOU. The intent of the Sport Pilot rating and LSA is to get more people - people without prior knowledge of aviation - into aviation.
Joe/Jane Average doesn't have an alliance to a particular engine manufacturer (chances are they've heard of Rotax, not Lycoming), doesn't care about the 10 kts because 120 already sounds real fast, and really doesn't care about how things have always been done - because for them it's ALL new.
They just want to do a little flying without having to get a second mortgage. And 30 hours of flying to get a license sounds a lot easier than 50 to 80 hours. Sport Pilot is the path of least resistance. And that's a good thing.
If you are participating in this conversation, consider yourself part of the lunatic-fringe of aviation. We care about everything - even the things that we shouldn't.
Most people that buy an LSA will use the same criteria that they use to buy a car; looks, value, economy, performance and a strong recommendation from a friend.
If they ever see this thread, or ones like it - they will be sure to stay clear of aviation. Because according to us, there is something wrong with everything.
Geico266
Well Known Member
gmcjetpilot said:
If I remember right the proposed weight limit was going to be 1270#'s and EAA lobbied the FAA hard to get the weight to 1320. This was (in part) to include existing aircraft such as the mighty Cub, Aeronca, Luscombe all featuring "conventional" engines (for about $30K BTW). So there is choice of which engine you want to use, and a wide variety of pricing. The S-19 is built around an 0-200 and the Rotax 912s so you have a choice as a builder also.
Several of the planes coming in from Europe are "certified" in their countries, just not here due to "politics".
Why do the planes coming into this country cost so much? One word; Liability. When a woman can spill a cup of McD's coffee on herself and get $3 million in damages how can an airplane manufacturer compete after a pilot makes a smokin hole in the ground. The planes that cost $100K should only cost $45K. But that is a whole other story.
I see the LSA rule as a huge boost to general aviation, and a place where (God willing) we will all be someday. Medicals are taken away everyday from pilots that are competent to fly. Are there going to be people who break the rules, of course, that is human nature. Some pilots fly right now with no license. Are there going to be pilots who can continue to fly legally for decades to come, by the thousands.
I look at Sport Pilot kinda like the Souix City plane crash a few years ago, it wasn't pretty, many fatalities, but though hard work & guts they got it on the ground (passed) and we can deal with changing the rules as they become apparent. The fact that the FAA has now allowed increased weight over the 1320 limit for floats, boat hulls, repositioning gears, BRS's (safety equipment) and others leads me to believe the glass is half full. Changes can and will be made as we, collectively, unitedly, ask for them in a reasonable, educated, and ORGANIZED manner. The EAA has been doing this for over 12 years now.
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RV6junkie said:
You just might be right about this. I have a co-worker who is starting ground school to get a sport pilot ticket and just the other day he told me he was ready to quit after only 4 classes, so I asked him why and he said: "between the fact the FAA has so many rules the that no human could ever comprehend them all and that fact that no one seems to be having much fun, it just doesn't seem worth the huge investment of time and money"
the_other_dougreeves
Well Known Member
Interesting that you suggest that on a LSA thread. Remember that there is the E-LSA, which is not subject to the 51% rule - the factory can provide the kit in just about any stage of completion. There are downsides, i.e., little deviation allowed from the kit, but build times can be WAY reduced with the e-LSA. If you could reduce completion times in the 200 hour range with standardized FWF assemblies and pre-fab wiring harnesses, you'd get a lot more interest. Rans has done this with the S-12XL, and it wouldn't surprise me to see Randy go the e-LSA route with the S-6, S-7 and/or S-12 designs.rv72004 said:
I agree with others here on the -12 about build time. Many more will get completed due to the layout and pulled rivet assembly. When you can see rapid progress, you stay motivated. It becomes a grind on my -10 working on it and seeing little progress it seems. So many parts...
On the engine front, well an IO-240 weighs 116 lbs. more than a 912S. It is completely non-viable in in an LSA if you plan to carry 2 people and fuel.
You don't need bigger engines, more weight or super slippery airframes to do the LSA mission and that is not what this class is about.
Sound wise, hmmm. with the Rotax supplied muffler you hear almost no exhaust note, it is mostly prop noise at full song. I was running up a 912 on the test stand and several people commented on how good it sounded. Sound is in the ear of the beholder.
The O-200 race engines are making their power at 4000 rpm, no different than modding a 912S to do duty at 7000. New rods, valve springs, cam, head porting and Voila, 150hp. No different than race prepping any engine for road racing. Been done millions of times successfully.
Engine reliability at high outputs has a lot more to do with design and the proper selection of parts. Big engines do not necessarily equate into reliability. I've said this before. Perhaps a few people remember what the AAR Toyota GTP cars did back in the the '90s. They obliterated all competition race after race including the 24 hour IMSA races. Powerplant? 2.1L turbocharged four. Competition? Porsche 3.2 L turbos, 3.5L F1 engines and 6L V8s- the best in the world. None could match the speed and reliability of these tiny motors. Nobody ever matched the win record in GTP of these engines.
I'll say the same applies in Unlimited racing where it takes a 3350 cubic inch engine with nitrous to beat a higher revving Merlin with about half the displacement. Neither are particularly reliable at these outputs but the 4 valve, smaller, liquid cooled engines are lighter and produce far higher specific outputs.
The liquid cooled heads on the 912 are a good idea and allows this engine to have high power density. The same lesson was learned by Porsche ultimately when hp levels finally rose above what could be accomplished by air cooling. From what I have seen, now a member of the Rotax world, the Rotax is probably cheaper to overhaul than a comparable O-235 or IO-240.
Lay people always sprout off this nonsense about small engines wearing out, blowing up with no facts to support this view and conveniently forget about thermal stresses on air cooled aircraft engines- the leading cause of premature parts replacements. Cracked heads. When you operate an aluminum alloy head at a temperature where almost half the material strength is gone- well the result is often predictable. Liquid cooling eliminates this cause almost entirely plus reduces the chances of exhaust valve problems as well.
As usual, we have people with no first hand experience or knowledge about Rotax engines making erroneous statements and stirring the pot. There is plenty of accurate information available to anyone willing to take a few minutes to educate themselves. Remember too, there are certified versions of the 9 series engines available. Believe me, it was not the simple stroke of a pen to get this approval. Every category was evaluated and tested.
The 912 series is really the best choice of engines for LSA compliant airframes. While Van is no engine expert, he is pretty savvy about all this and made the engine choice based on the facts. Just like the Lycomings make good sense on the 4 through 10 airframes, the Rotax does on the 12.
On the engine front, well an IO-240 weighs 116 lbs. more than a 912S. It is completely non-viable in in an LSA if you plan to carry 2 people and fuel.
You don't need bigger engines, more weight or super slippery airframes to do the LSA mission and that is not what this class is about.
Sound wise, hmmm. with the Rotax supplied muffler you hear almost no exhaust note, it is mostly prop noise at full song. I was running up a 912 on the test stand and several people commented on how good it sounded. Sound is in the ear of the beholder.
The O-200 race engines are making their power at 4000 rpm, no different than modding a 912S to do duty at 7000. New rods, valve springs, cam, head porting and Voila, 150hp. No different than race prepping any engine for road racing. Been done millions of times successfully.
Engine reliability at high outputs has a lot more to do with design and the proper selection of parts. Big engines do not necessarily equate into reliability. I've said this before. Perhaps a few people remember what the AAR Toyota GTP cars did back in the the '90s. They obliterated all competition race after race including the 24 hour IMSA races. Powerplant? 2.1L turbocharged four. Competition? Porsche 3.2 L turbos, 3.5L F1 engines and 6L V8s- the best in the world. None could match the speed and reliability of these tiny motors. Nobody ever matched the win record in GTP of these engines.
I'll say the same applies in Unlimited racing where it takes a 3350 cubic inch engine with nitrous to beat a higher revving Merlin with about half the displacement. Neither are particularly reliable at these outputs but the 4 valve, smaller, liquid cooled engines are lighter and produce far higher specific outputs.
The liquid cooled heads on the 912 are a good idea and allows this engine to have high power density. The same lesson was learned by Porsche ultimately when hp levels finally rose above what could be accomplished by air cooling. From what I have seen, now a member of the Rotax world, the Rotax is probably cheaper to overhaul than a comparable O-235 or IO-240.
Lay people always sprout off this nonsense about small engines wearing out, blowing up with no facts to support this view and conveniently forget about thermal stresses on air cooled aircraft engines- the leading cause of premature parts replacements. Cracked heads. When you operate an aluminum alloy head at a temperature where almost half the material strength is gone- well the result is often predictable. Liquid cooling eliminates this cause almost entirely plus reduces the chances of exhaust valve problems as well.
As usual, we have people with no first hand experience or knowledge about Rotax engines making erroneous statements and stirring the pot. There is plenty of accurate information available to anyone willing to take a few minutes to educate themselves. Remember too, there are certified versions of the 9 series engines available. Believe me, it was not the simple stroke of a pen to get this approval. Every category was evaluated and tested.
The 912 series is really the best choice of engines for LSA compliant airframes. While Van is no engine expert, he is pretty savvy about all this and made the engine choice based on the facts. Just like the Lycomings make good sense on the 4 through 10 airframes, the Rotax does on the 12.
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JimLogajan
Active Member
Speed of build
I too would like a quick build plus a speedy plane without spending too much. So I would suggest you consider adding the Arion Lightning (http://www.arionaircraft.com/index.html) to your list of candidates. The prototype's first flight was on March 6, 2006 and as of February 28, 2007 I believe there are at least 5 customer-built Lightnings now flying, confirming that build time may be accomplished in weeks and months, not years.
Here's a cost comparison of airframe + engine for a quick-build RV-9A and a Lightning:
Basic Cost:
Lightning: Airframe $33,900 + Engine $14,900 = $48,800
RV-9A QB: Airframe $27,415 + Engine $22,450 = $49,865
Some basic speed comparisons:
Lightning: Cruise: 175 mph; Max: 190 mph; Stall, full flap: 45 mph
RV-9A: Cruise: 187 mph; Max: 195 mph; Stall, full flap: 50 mph
And some weight comparisons (non-LSA):
Lightning: Available payload: 650 lbs; Full fuel (23 gal) payload: 512 lbs
RV-9A: Available payload: 675 lbs; Full fuel (36 gal) payload: 459 lbs
Ranges at the listed cruise speeds and full fuel are both claimed to be 700 sm, though Arion indicates a reserve is included and Vans does not. At comparable speeds the Lightning appears to be at least 50% more energy efficient.
I should note that I bought the preview plans for the RV-9A but obviously I am not yet committed to that plane.
If low cost were a higher priority and I was willing to sacrifice some aircraft speed and take a bit longer time to build, neither the RV-12 or Rans S-19 would be considered for the simple fact that they aren't yet being sold! The only comparable contender on my list with that revised set of priorities is the Zenith Zodiac XL. Whether you prefer it be powered by Lycoming, Rotax, Jabiru, Corvair, or rats running on a treadmill, you're likely to find someone has already built one with an engine you like.
Phyrcooler said:
I too would like a quick build plus a speedy plane without spending too much. So I would suggest you consider adding the Arion Lightning (http://www.arionaircraft.com/index.html) to your list of candidates. The prototype's first flight was on March 6, 2006 and as of February 28, 2007 I believe there are at least 5 customer-built Lightnings now flying, confirming that build time may be accomplished in weeks and months, not years.
Here's a cost comparison of airframe + engine for a quick-build RV-9A and a Lightning:
Basic Cost:
Lightning: Airframe $33,900 + Engine $14,900 = $48,800
RV-9A QB: Airframe $27,415 + Engine $22,450 = $49,865
Some basic speed comparisons:
Lightning: Cruise: 175 mph; Max: 190 mph; Stall, full flap: 45 mph
RV-9A: Cruise: 187 mph; Max: 195 mph; Stall, full flap: 50 mph
And some weight comparisons (non-LSA):
Lightning: Available payload: 650 lbs; Full fuel (23 gal) payload: 512 lbs
RV-9A: Available payload: 675 lbs; Full fuel (36 gal) payload: 459 lbs
Ranges at the listed cruise speeds and full fuel are both claimed to be 700 sm, though Arion indicates a reserve is included and Vans does not. At comparable speeds the Lightning appears to be at least 50% more energy efficient.
I should note that I bought the preview plans for the RV-9A but obviously I am not yet committed to that plane.
If low cost were a higher priority and I was willing to sacrifice some aircraft speed and take a bit longer time to build, neither the RV-12 or Rans S-19 would be considered for the simple fact that they aren't yet being sold! The only comparable contender on my list with that revised set of priorities is the Zenith Zodiac XL. Whether you prefer it be powered by Lycoming, Rotax, Jabiru, Corvair, or rats running on a treadmill, you're likely to find someone has already built one with an engine you like.
Mike Armstrong
Well Known Member
Rv6ejguy, your on a roll, seriously, your making alot of sence here and folks should go back and re-read your posts in this thread.
It is indeed very easy to for 'us' to forget the true intent of Sport Pilot other than a means of continuing to legally fly when we think/know our medical might/will fail. However, to the general public, those that it is intended for, its simply a means to finally be able to fly 'real' airplanes (sorry ultralighters, but I think most of the general public sees ultralights as neat/cute but scary as ****). The flight parameters ('restrictions' as we see it) of Sport Pilot are more than adequate for Joe Public to realize their flying dreams and enable them to move on to a PP later if they want to, thats what it was intended for. Its those of us that want to go faster, higher and carry more weight for longer periods of time that are having issues with it, not Joe Public. He/she justs wants to enjoy the fun of flying, not a bad idea. You know, the uncomplicated, low and slow, around the patch basic kind of fun flying that alot of people have forgotten about. Sport Pilot and LSA's will fit this bill perfectly.
Sport Pilot and LSA's are here to stay. The rules and regs have already been hashed out for years and what you see is what was finally decided on. If your one of the folks that find it unacceptable, ie you dont like the flight 'limitations' or performance 'restrictions' it carries then it is clearly not for you and your clearly not for whom it was intended for. But keep in mind that those new pilots that are enthusiastically entering Sport aviation are happy to be able to do so and do so willingly, as opposed to perhaps many veteran pilots that are used to flying GA aircraft and/or are now 'forced' (as opposed to being grateful to be able to continue to legally fly) into the Sport Pilot catagory because of their health.
We can argue/debate all we want, which dont get me wrong, is fun to do, but there are folks alot smarter than me (and probably most on this Forum) like Van or the the designers of the S-19 that know what their doing and have done so successfully for many years that have come up with their own LSA design. I'm sure they have very good reasons for what they have decided on. Who am I to say their wrong in which engine they have chosen or what feature they've decided is best? I may find one ugly, hard to get into or not understand the removable wing option but there will be others that will love it. Oh well, if its an LSA I want then theres many more aircraft ,kits and otherwise, out there that meet the Sport Pilot parameters that I can choose from.
I'll be curious to see what these two designers settle on as their 'final' design and then see them side by side. In the end I may not be interested in either one of them, who knows .
It is indeed very easy to for 'us' to forget the true intent of Sport Pilot other than a means of continuing to legally fly when we think/know our medical might/will fail. However, to the general public, those that it is intended for, its simply a means to finally be able to fly 'real' airplanes (sorry ultralighters, but I think most of the general public sees ultralights as neat/cute but scary as ****). The flight parameters ('restrictions' as we see it) of Sport Pilot are more than adequate for Joe Public to realize their flying dreams and enable them to move on to a PP later if they want to, thats what it was intended for. Its those of us that want to go faster, higher and carry more weight for longer periods of time that are having issues with it, not Joe Public. He/she justs wants to enjoy the fun of flying, not a bad idea. You know, the uncomplicated, low and slow, around the patch basic kind of fun flying that alot of people have forgotten about. Sport Pilot and LSA's will fit this bill perfectly.
Sport Pilot and LSA's are here to stay. The rules and regs have already been hashed out for years and what you see is what was finally decided on. If your one of the folks that find it unacceptable, ie you dont like the flight 'limitations' or performance 'restrictions' it carries then it is clearly not for you and your clearly not for whom it was intended for. But keep in mind that those new pilots that are enthusiastically entering Sport aviation are happy to be able to do so and do so willingly, as opposed to perhaps many veteran pilots that are used to flying GA aircraft and/or are now 'forced' (as opposed to being grateful to be able to continue to legally fly) into the Sport Pilot catagory because of their health.
We can argue/debate all we want, which dont get me wrong, is fun to do, but there are folks alot smarter than me (and probably most on this Forum) like Van or the the designers of the S-19 that know what their doing and have done so successfully for many years that have come up with their own LSA design. I'm sure they have very good reasons for what they have decided on. Who am I to say their wrong in which engine they have chosen or what feature they've decided is best? I may find one ugly, hard to get into or not understand the removable wing option but there will be others that will love it. Oh well, if its an LSA I want then theres many more aircraft ,kits and otherwise, out there that meet the Sport Pilot parameters that I can choose from.
I'll be curious to see what these two designers settle on as their 'final' design and then see them side by side. In the end I may not be interested in either one of them, who knows
.
