Fuel Consumption for S300CB

[Super Petey-O]

Aside from seeing one listing on their brochure (I think it was for the CBi), I can not find any literature on the the fuel consumption rates for the schweizer. It is not even listed in the Pilot's flight manual / HIM. If any one has any good sources or rules of thumb for fuel consumption rates in the S300CB (269C-1) I'd love to hear them.

 

Thanks

[lelebebbel]

For some reason you won't find these numbers in flight manuals for most piston machines. Probably a liability thing or something.

We have the CBi listed at 45 liters/hour (thats just under 12gal for all you imperialists) in our ops manual, realistically its a bit less than that depending on load, weather, altitude etc.

 

Edit: sorry, you were looking for the CB. That's in there, too, but I can't remember the figure.

 

Edit2 : 300CB and CBI are both listed at 45ltr/hr in there.

Edited December 22, 2010 by lelebebbel

[Super Petey-O]

For some reason you won't find these numbers in flight manuals for most piston machines. Probably a liability thing or something.

We have the CBi listed at 45 liters/hour (thats just under 12gal for all you imperialists) in our ops manual, realistically its a bit less than that depending on load, weather, altitude etc.

 

Edit: sorry, you were looking for the CB. That's in there, too, but I can't remember the figure.

 

Edit2 : 300CB and CBI are both listed at 45ltr/hr in there.

 

Yep that's about what I use for planning. Not really an exact science though. Thanks for the reply

[Shaun]

For some reason you won't find these numbers in flight manuals for most piston machines.

 

I think it's a helicopter thing, every piston airplane I've seen has detailed fuel consumption tables for multiple power settings.

 

I don't understand why they don't put a fuel flow gauge in all aircraft.

[ADRidge]

I don't understand why they don't put a fuel flow gauge in all aircraft.

 

Thank you. I've been saying the same thing for two years.

[adam32]

 

I don't understand why they don't put a fuel flow gauge in all aircraft.

 

Weight and cost...

[Shaun]

Weight and cost...

 

A sensor, LED gauge, and wires would weigh a few ounces.

 

The cost might be offset by decreased fuel planning mistakes, extended range by requiring less of a buffer during planing, and better fuel economy since the pilot can find the actual best range speed.

 

Aviation has this weird liability paradigm where safer components and designs are scrapped in favor of 40 year old technology that you can't be sued for.

 

But in the end isn't the cost of all the carb heat accidents and training less than the cost of just putting a small heating element in the throttle?

[adam32]

 

 

Aviation has this weird liability paradigm where safer components and designs are scrapped in favor of 40 year old technology that you can't be sued for.

 

 

 

Yeah I haven't figured that one out yet...I mean, some planes and helicopters still have points in them! What was the last car with points, the 70's?

[apiaguy]

ahhh... thread hijack...

 

I used to feel the same way about aviation technology when I was a youngling in A&P school.... I now feel very different about what you consider 40 year old tech...

 

Aviation equipment is based on reliability... I would contend that if we had a fleet of airplanes and helicopters with electronic ignition and computer fuel injection we would experience as many if not more accidents. The performance gains would be minimal and the fuel savings minimal as well. Bring on your data to support your new technology. Remember when anyone could fix their car... you didn't need a computer to tell you what it "thought" was the problem. Many computer based diagnostic programs don't really tell you what's wrong in a complex system... merely tells you what sensor is out of parameter in the program.

[r22butters]

Aviation has this weird liability paradigm where safer components and designs are scrapped in favor of 40 year old technology that you can't be sued for.

 

Is that why the 'CB' doesn't have a low-rpm warning system?

[iChris]

Is that why the 'CB' doesn't have a low-rpm warning system?

 

The CB is not a Part 27 aircraft, low rpm warning was not required at the time of certification under CAR Part 6.

 

The 300 (269) series were not certificated via Part 27. The 300C, CB, CBi were type certificated by amendment to type certificate 4H12 under airworthiness requirements of the historical Civil Aeronautics Regulations (CAR part 6).

Under the privileges of "Delegation Option Authorization" the amendment was approved (1970). This provision allowed Production Certificate Holders to obtain an aircraft airworthiness certificate without further showing and authorization to sign and issue airworthiness certificates.

However, as of November 2009 no person may perform any function contained in a prior Delegation Option Authorization (21.235 (d]).

Ref.

 

FAR 21.163, 21.231, 21.235, and AC21-1B.

 

Under current FAR 27.33

 

(e) (1) The warning must be furnished to the pilot in all flight conditions, including power-on and power-off flight, when the speed of a main rotor

approaches a value that can jeopardize safe flight

 

(e) (3) The warning must be clear and distinct under all conditions, and must be clearly distinguishable from all other warnings. A visual device that requires the attention of the crew within the cockpit is not acceptable by itself.

Edited December 23, 2010 by iChris

[Shaun]

ahhh... thread hijack...

 

Bring on your data to support your new technology. Remember when anyone could fix their car... you didn't need a computer to tell you what it "thought" was the problem. Many computer based diagnostic programs don't really tell you what's wrong in a complex system... merely tells you what sensor is out of parameter in the program.

 

Uh modern cars are infinitely safer and more reliable than old ones. Cars made after 2000 don't even need a tune up, in addition they have much better fuel economy, air bags, traction control, driver sleep warning systems, radar braking, ABS, a slew of indicators such as tire pressure. Yes you have more spurious warnings but on-board computers have revolutionized maintenance.

 

You get so much and cars are cheaper than ever. You can drive a modern Honda from 0-150,000 miles without a single problem and at a fuel economy and level of safety never seen before.

 

Maybe you want to drive a car from the 70's but I don't. I really can't see the argument that technology should be frozen, by your logic a plane form the 30's would be even better.

 

Burt Rutan designed a composite multi engine airplane that suffers no adverse aerodynamic swings after engine failure, this would save hundreds of lives, replacing the infamous doctor killers, what is the logical argument against that?

[apiaguy]

Don't get me wrong... I'm not against technology... it is changing aviation too. All the things you listed as advances in automobiles are not necessarily good things for aviation.. at least when it comes to operating costs... complexity adds cost (I don't mean purchase price)

I will forever argue that cars after 2000 don't need tune-ups

I don't believe they get any better fuel economy than cars made before 2000.. unless you consider hybrids.. which are not comparable and I don't think have a place in aviation yet.

Instead of continuing on I'll summarize that my point is I believe we have the ability to have any useful technology in aviation...just because there are more stringent rules in place before a manufacturer can use something isn't necessarily a bad thing. We aren't still using magnetos because of the rules. Old technology isn't necessarily bad technology. The "new" technology items are really not providing significant benefit and I believe that is why we are slow to change. If there really was an automotive engine that made a good aircraft engine it would be out there and in use... the truth is the benefits are NOT revolutionary.. merely evolutionary.

[iChris]

Aside from seeing one listing on their brochure (I think it was for the CBi), I can not find any literature on the the fuel consumption rates for the schweizer. It is not even listed in the Pilot's flight manual / HIM. If any one has any good sources or rules of thumb for fuel consumption rates in the S300CB (269C-1) I'd love to hear them.

 

Thanks

 

Schweizer’s DOC documents quotes the fuel flows for the 300C @ 11.8gph and the 300CBi @ 10.5. So that would place the 300CB some were in between, likely nearer to the CBi.

 

Lycoming charts fuel flow for the HO-360-C1A (CB engine) as shown:

 

 

[Shaun]

complexity adds cost

 

Yes but many things are more than worth the small chance of a part failure or maintenance costs, like a fuel flow gauge, airbags, GPS, ABS, etc.

 

 

I don't believe they get any better fuel economy than cars made before 2000..

 

http://www.sightline.org/images/blog-2008/Mileage-horsepower-EPA-600.gif

 

http://daily.sightline.org/daily_score/archive/2008/02/26/horsepower-vs-mpg

 

 

 

more stringent rules in place before a manufacturer can use something isn't necessarily a bad thing.

 

If the rules are to stringent as to stifle innovation, than safety and performance suffer.

 

This combined with the GARA lawsuit immunity set at 18 years, and the propensity of people to sue propeller manufacturers when their loved one dies after overloading a Cessna at 8000 feet, incentivizes companies to stick with older designs. Not, in my opinion, to make the aircraft safer, but to save money.

[apiaguy]

The story and graphs only illustrate a change in design by the auto mfg

 

from the article:

" The fuel savings were the result of two simultaneous trends: the average car got lighter, and engineers tuned new car engines for efficiency rather than power and acceleration. In short, the auto industry -- from boardroom to design shop to factory floor -- focused its efforts on squeezing more miles out of less gasoline. "

 

There is always a trade off... aviation mfg's have done similar shifts... and currently the shift is not to save fuel... it is to go fast.. carry more... and have more power.

[Shaun]

The story and graphs only illustrate a change in design

 

Yes initially there was no technology advancement just a movement of resources. But look at the graph, after the 80's the lost HP was regained and soared, the cars put back on the weight (SUV's), but the engines themselves are much better.

 

Take the dot on 2006 and compare it to the one form 1975, it has 8 more MPG and 80 more HP. That's a massive increase, so to the original point of using aircraft who's technology is mired in the 70's VS. something new, I'll take the latter.

[apiaguy]

I agree that the technology boost would be great and is marred in gov't regs... I also believe there isn't a simple answer out there that would show a marked improvement in aviation compared to the auto info you've illustrated.

Edited December 23, 2010 by apiaguy

[Tarantula]

I will say that I believe that the costs of certifying a new engine, combined with the increased liability for the company by not using a "proven" engine, is the main reason companies don't want to make the change. The certification itself is prohibitive in cost, and with the chance of lawsuits on top of it, it makes no sense for the company to do so.

[adam32]

I will say that I believe that the costs of certifying a new engine, combined with the increased liability for the company by not using a "proven" engine, is the main reason companies don't want to make the change. The certification itself is prohibitive in cost, and with the chance of lawsuits on top of it, it makes no sense for the company to do so.

 

Winner winner!!

[apiaguy]

I'd still have to disagree somewhat... yes the cost of certification doesn't make sense to many small engine designs.. but those designs are no major milestones...

Look at the experimental market.. many auto engines used and still few are a substantial departure from the "proven"... yes some may have better fuel burn... but it comes at a cost somewhere else.. say reliability. If you go build an experimental helicopter or airplane what engine are you going to put in it??? (not including turbine)

Since there are no regs to impede your creativity lets hear the solution? And will anybody decide that the new engine is worth the trade-off? I say this because in 20 year of certified and experimental maintenance I haven't seen anything that I'd rather go with besides a lycoming or continental... except a turbine.

[r22butters]

The CB is not a Part 27 aircraft, low rpm warning was not required at the time of certification under CAR Part 6....

 

That explains why it didn't originally have one, but does cost over safety explain why they never installed them later?

 

Still,...it would have been nice to have one. Especially on a helicopter with no governor, that reaches full throttle while still barely chugging about!

[lelebebbel]

I'd still have to disagree somewhat... yes the cost of certification doesn't make sense to many small engine designs.. but those designs are no major milestones...

Look at the experimental market.. many auto engines used and still few are a substantial departure from the "proven"... yes some may have better fuel burn... but it comes at a cost somewhere else.. say reliability. If you go build an experimental helicopter or airplane what engine are you going to put in it??? (not including turbine)

Since there are no regs to impede your creativity lets hear the solution? And will anybody decide that the new engine is worth the trade-off? I say this because in 20 year of certified and experimental maintenance I haven't seen anything that I'd rather go with besides a lycoming or continental... except a turbine.

 

I agree, there aren't any better aircraft engines around. But, not because it would be too hard to design and make them. The technology has long since been available. The problem is that none of the "serious" engine makers will risk spending the money on development and certification for a comparatively tiny market. Experimentals? That market is even tinier, and even without certification costs, I think the big companies like Cummins, Ford or Daimler etc. won't risk liability lawsuits for that.

 

So we are stuck with a hopelessly outdated but proven design from the 40s, and the experimental world is stuck with their often ill-adapted or otherwise questionable lawnmower engines...

I don't expect any major changes to that situation until they stop making 100LL. Then we'll hopefully see some good Diesel/JetA piston engines.

Edited December 24, 2010 by lelebebbel