Board index

Sport Pilot Talk

The discussion forum for Sport Pilots and Light Sport Aircraft
* * * CHECK Out the Sport Pilot Talk Flight School and Rental Finder Map! * * * It is currently Wed Jun 19, 2013 7:20 am

All times are UTC - 5 hours




Post new topic Reply to topic  [ 134 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 9  Next
Author Message
PostPosted: Fri Feb 04, 2011 1:01 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
eidolon45 wrote:
With full tanks, it only has about 350 # or less useful load.


Yes, weight and fuel load are concerns. To make this a more meaningful discussion, I suggest we standardize terminology. The difference between maximum gross weight and empty weight is useful load -- typically 500 to 550 pounds in most S-LSAs. The remaining weight with full fuel tanks is called payload -- and that 350# figure is pretty typical. So, we're talking two FAA-standard 170 pound adults, plus ten pounds of baggage. If the people or baggage weigh more, the only answer is to reduce the fuel carried.

In my SportStar (1268 pounds max gross; I haven't done the vortex generator mod yet), empty weight is 745 pounds. That leaves a useful load of 523 pounds. Full fuel (31.5 gallons) weighs 189 pounds, which leaves a 334 pound payload. For dual instruction, I only carry 16 to 20 gallons of fuel (still good for 3 to 4 hours, or 2-3 hour lessons with plenty of reserve).

When I do the mod to raise the max gross weight to the LSA limit, the resulting numbers become: useful load=575 pounds; payload=386 pounds. So, the 162 is certainly comparable to the other S-LSAs out there.

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 1:17 pm 
Offline

Joined: Sun Sep 10, 2006 8:30 pm
Posts: 593
I like how some of the new manufacturers have the weight for every option listed on their website. If you add up items they all come with a weight to see where the useful load ends up.

Anyone flying a 162 who has a real world weight and balance? It would be interesting to see the weights for a normal VFR equipped airplane.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 1:33 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
Cub flyer wrote:
I like how some of the new manufacturers have the weight for every option listed on their website.


Yes! Not only that, but many of them supply the station at which each option is installed. With that plus the empty weight center of gravity, you can easily find out what combination of options are likely to take you out of the loading envelope. Just compare this to the sloppy wt/balance info provided with Cubs, Ercoupes, and Luscombs ("weight under 800 pounds, with the CG near the front of the wing", to see how far the industry has come in the past 65 years.

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 2:49 pm 
Offline

Joined: Mon Nov 10, 2008 12:44 pm
Posts: 64
3Dreaming wrote:
LightSportFlyer wrote:
3Dreaming wrote:
The Continental o-200D weighs in at 176.5 dry from the TCDS. This would go along with the 40 pound weight penalty over the Rotax I had heard about. The Rotax weighs in around 120 plus add all the required item needed for the installation and it is between 140-145. Tom


According to Rotax's own website when you add the listed options onto it's base weight the total for the 912S comes out to 165.8 lbs. I'd be more than happy to leave out 2 gallons of fuel to make up the difference and gain the huge service network the O-200 has vs the Rotax's comparatively small number of qualified mechanics available. LSAs with Rotaxes have been out for 7 years now and getting service is still a problem in many areas.

http://www.rotax-aircraft-engines.com/p ... _S_ULS.pdf


LightSportFlyer, good to hear from you again. I know you don't like foreign made engines, but please try to be accurate in your compairisons. If you had looked at the list of items you were adding you would have seen that not all of them are needed. I mean who would put a propeller governor on an engine for a light sport airplane that can not use a variable pitch prop. The weight I posted came from the FAA TCDS for the O-200D, but from Continental's site the dry weight installed is 199 pounds. http://www.genuinecontinental.aero/o-200.html Lets make a fair comparison for the Rotax. From the web site you posted The engine base weight is 124.8. For the installation I am familiar with you have the oil radiator 1.2, Radiator 2.2, slipper clutch 3.7, Airguide hood 1.8, mounting frame 4.4, and 3/4 gallon of coolant to be fair 6.0. I don't think continental includes airbox or exhaust, but I will add them in anyway 11.6 for both. That gives a difference of 43.3 pounds, but take out the exahust and airbox and the difference is 54.9 pounds. If you want to add in the external generator you can add in 6.6 pounds, but you are still looking at about a fifty pound advantage in weight for the Rotax.
Also with the recent FAA ruling any A&P can work on the Rotax engine without training from Rotax. All they have to do is meet the CFR requirements of having training in the task being performed just like for the continental and Lycoming.


I know your opinions are bought and paid for by Rotax so I will trust my own figures. As to weight differences once again being able to get a traditional engine serviced at any airport is far more valuble to me than however many lbs heavier the Conti is.

And as for (as you put it), "any A & P can work on the Rotax without training from Rotax" - that is more foolish than having someone work on my complex Cadillac engine without training from the manufacturer. I also want him to have alot of experience working on the engine, which is even harder to find in a Rotax mechanic.

Cessna seems to be rapidly ramping up production of the 162 and releasing more of them than many other builders. The O-200 will soon become the most popular LSA engine out there. That's all the proof I need as to which engine is best for me, to each his own.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 3:16 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
Speaking as an aeronautical engineer, and aviation maintenance technician with 30 years' experience on Lycoming engines, I can tell you that coming up to speed on the Rotax was delightfully simple. I took two of the three Rotax courses (service and maintenance levels -- I'll leave the heavy maintenance course for later, because I have no need to do overhauls at this time). Each course runs just one weekend (16 classroom hours), and is well within the capabilities of any A&P who has ever worked on any engine. Cost of each course is modest (around $500 or so). The courses won't make you a mechanic (you already should be one before enrolling), but teach you what's different or special about the Rotax. I see no reason for any A&P or LSRM not to become Rotax factory certified, regardless of what the FAA says.

So, why are there so few Rotax mechanics out there? At one time, the answer was that there was little demand. But with LSA now the fastest growing segment of GA, and with Rotax powering 80% of the LSA fleet, that is no longer the case. I think many mechanics are just afraid of them -- anything new is outside their comfort zone. If they only realized how intuitive the design is, and how easy (and pleasurable) the Rotax 912 ULS is to work on, I think we'd see a lot more mechanics out there.

The Rotax 912 ULS now has a 2000 hour TBO (the same as an O-200) and costs $19,000 new. Both Continental and Lycoming websites say "call for price", so I can't give you a comparison -- but overhauled O-200s are going for around $14,000.. As for actual installed weights: my SportStar weighs in at 745 pounds empty. An Ercoupe 415C in which I instruct is 805 pounds, and is Continental 75-powered. The airframe weights are similar, so you can see that the Cont 75 is about 60 pounds heavier than the Rotax. The O-200 is heavier still. The Rotax seems to have about the best power to weight ratio in its class.

I have no commercial affiliation whatever with Rotax (or Continental, or Lycoming for that matter) and have flown and instructed in airplanes powered by all three engines, for decades -- thus, I think my opinions are relatively unbiased.

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 3:29 pm 
Offline

Joined: Sun Sep 10, 2006 8:30 pm
Posts: 593
I think the 162 production will probably switch over to the LSA Lycoming as soon as they get it ready. In house brand makes sense for Cessna.

I learned my lesson with the 912. I destroyed one early on due to a dumb mistake on my part. It's not hard to work on just different. I have no problem flying behind them. Actually the 2 strokes never gave me any trouble. As an opinion they are fine as long as you follow instructions exactly. The Lycoming and Continental seem more forgiving of dumb mechanic and pilot mistakes and lack of use.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 3:52 pm 
Offline

Joined: Mon Nov 10, 2008 12:44 pm
Posts: 64
Cub flyer wrote:
I think the 162 production will probably switch over to the LSA Lycoming as soon as they get it ready. In house brand makes sense for Cessna.


Even better, plus Lycomings IO-233 is fuel injected, offers continuous power ratings up to 115 horsepower, and has an industry-leading time between overhaul (TBO) of 2400 hours - Can the Rotax 912S do all that ?


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 4:00 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
LightSportFlyer wrote:
Can the Rotax 912S do all that ?


No, and it remains to be seen whether Lycoming can (at least in production quantities, at a reasonable weight and price). There are challenges, but I'm rooting for them. After all, I live in Lycoming County, and am retired from Lycoming College! :wink:

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 6:11 pm 
Offline

Joined: Sun Sep 10, 2006 8:30 pm
Posts: 593
The 400 hours more TBO is not really too important except to a flight school. Around here a lot of private owned airplanes suffer corrosion from lack of use and may not make TBO.

Overhaul cost at the end of the TBO is also something to consider. The standard O-200's in a Cessna 150 are getting pretty expensive.

I just spent 12,000 overhauling a C-85 continental. My cost on all the parts


Top
 Profile  
 
 Post subject:
PostPosted: Fri Feb 04, 2011 6:19 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
Cub flyer wrote:
Overhaul cost at the end of the TBO is also something to consider.


Given the comparative costs, and the specialized tooling involved, I'm leaning toward just buying a new-in-the-crate 912ULS when I hit TBO, instead of trying to do an overhaul. But here's another thought, from Brian Carpenter (Rainbow Aviation): maintenance needs on a Rotax are pretty low for the first 1000 hours, then rise sharply all the way to TBO. For a flight school (where downtime translates to lost revenue), he suggests pulling the engine at midtime, putting in a new one, and then selling the 1000 hour engine on eBay to a homebuilder, for whom it will then last ten years or more.

Quote:
I just spent 12,000 overhauling a C-85 continental. My cost on all the parts


Ouch!

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 05, 2011 8:41 am 
Offline

Joined: Mon Nov 10, 2008 12:44 pm
Posts: 64
drseti wrote:
LightSportFlyer wrote:
Can the Rotax 912S do all that ?


No, and it remains to be seen whether Lycoming can (at least in production quantities, at a reasonable weight and price). There are challenges, but I'm rooting for them. After all, I live in Lycoming County, and am retired from Lycoming College! :wink:


They already are, open your eyes and give your bias a rest for once.

http://www.renegadelightsport.com/

http://www.looptv.aero/LTVCategory16/23 ... 3-LSA.aspx


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 05, 2011 9:09 am 
Offline

Joined: Thu Mar 06, 2008 11:23 am
Posts: 361
Location: Allen, TX
One ANNOUNCED aircraft model with zero registered with the FAA neither constitutes a 'they' or indicates production volume. As drseti said we need to wait and see how Lycoming does.

Dry weight for the 233 is listed as 215lbs.

_________________
dave


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 05, 2011 9:44 am 
Offline

Joined: Wed Oct 06, 2010 9:55 pm
Posts: 11
Location: Marietta, Georgia
I have to agree with dstcair. One of our manufacturers has been waiting on an O-233 experimental/ test engine from Lycoming for a long while. I talked to the Lycoming guy at Sebring and asked we we could expect to get one. He said "Soon". Same thing they said at Airventure. Lycoming has not shipped a "production" O-233 yet and probably won't for at least a couple of months. Prices will be something above $21,000 depending on options.

I look forward to the day when Lycoming delivers and the engines actually enter widespread service. If the engine is what is promised, it will will give the 912 some healthy competition. Until then, the Rotax is still hard to beat for overall weight/power/economics. IMHO!

_________________
Mike is chief hangar sweeper at Hansen Air Group, dealers for Sky Arrow, FK, and Peregrine LSAs.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 05, 2011 10:42 am 
Offline

Joined: Sun Sep 10, 2006 8:30 pm
Posts: 593
I was thinking about the sight gauges. I have them in the PA-11 and I hate to admit but I really don't look at them much. It's a lot more than normal scan to look up behind you in the wing roots. Also I don't like having the fuel in clear tubes that could be vulnerable in a crash where a wing is pulled loose. I guess the fuel supply lines would also be a problem so it might not matter.

I'd rather electric gauges with wing tanks to have a clearly marked gauge on the panel. If they were accurate. I haven't owned a light airplane yet with good fuel gauges except the stock J-3. Wire and float is hard to mess up. Why do cars seem to have gauges that work great for years? Airplane tanks are too flat I guess.

Advantage of the sight gauge is you can lean in the cabin and see the fuel level without turning on the master.

Yes I stick my tanks before each flight.

_________________
"Perfection is finally attained not when there is no longer anything to add but when there is no longer anything to take away." Antoine de Saint Exupery


Top
 Profile  
 
 Post subject:
PostPosted: Sat Feb 05, 2011 12:13 pm 
Offline
User avatar

Joined: Sat Nov 28, 2009 6:42 pm
Posts: 2575
Location: Lock Haven PA
LightSportFlyer wrote:
open your eyes and give your bias a rest for once.


My bias, such as it is, comes from frequent discussions with Rick, an engineer at Lycoming who has far more knowledge about this engine than you or I. He tells me that they are still trying to reduce weight, and are not up to quantity production yet. I will see him Monday night at the Williamsport Regional Association of Pilots meeting, and will post an update here.

_________________
The opinions expressed in this post are those of one CFI, and do not necessarily represent the position of the FAA or its lawyers.
Prof. H. Paul Shuch, Ph.D., CFII, LSRM-A/GL/WS
AvSport of Lock Haven
http://AvSport.org fly@AvSport.org


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 134 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 9  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group

Archive