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difference between J160 and LSA


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J160 Longer tail, bigger rudder,(less aileron/rudder co-ordination required) wider body , greater payload slower climb, fits us fat buggers better...:thumb_up:


LSA narrower body short tail, small rudder must co-ordinate turns with rudder and aileron, less fuel, twitchier, lower weight and climbs like a homesick angel. Not as comfortable for us fat buggers thumb_down


Both will cruise at 95 knots. Both can handle a bit of baggage.


LSA is more sporty, J160 is a better x country plane...


LSA 65L of fuel and J160 130L? of fuel....anyway a lot...in the J160


My 2 bobs worth...







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136 litres useable in J160.


Phil gives a very good "Readers Digest" version of the differences.


LSA only has a useful load of about 185kg, making 2 people and fuel a problem, especially if they are two heavy people (if you want to stay legal!)


J160 carries a useful load of about 240kg.



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Probably it would be best if you read up on the following LSA [ Light Sport Aircraft ] requirements taken from the RAAus web site; http://www.auf.asn.au/operations/LSA_explained.html


Perhaps to clarify, I assume you are not referring to the original small fuselage 55 series Jabirus which are often referred to as LSA's but to the new international LSA category aircraft that are now appearing in increasing numbers of makes and types.


If you intend to kit build then that aircraft will not conform to an LSA category aircraft.


LSA aircraft must be factory built, conform to strict testing and quality controls which under LSA rules, can be carried out by the manufacturer who can then certify that aircraft as meeting all the necessary requirements for registration in the LSA category.


Unlike any kit built or non certified aircraft, this certified LSA aircraft can then be used for hire and reward.


As the aircraft is certified by the manufacturer who is responsible for the design and integrity of the aircraft, alterations to any part of the aircraft can NOT be made without the manufacturer's or certifier's express permission.


Even the fitting of a VSI to our J120's sparse panel needed Jabiru's approval which in this case was readily granted.


A factory built J160 is approved as an LSA aircraft but it's MTOW is only certified [from Jabiru's web site ] as 540 kgs and useable load including fuel as 245kgs.


The lower MTOW is to meet the LSA requirements on maximum stall speeds at MTOW.


The situation was created by a high wing loading at MTOW due to the short span and therefore small wing area.


The near identical factory built J170 with another 1.5 metres span and a greater wing area, a slower stall speed as a result of more span and slower approach speeds and a shorter T/O run is a certified LSA with a MTOW of 600kgs and a useable load of 290 kgs.


[ The MTOW for any LSA certified aircraft is 600 kgs unless the manufacturer specifies a lower figure.]


The only difference in these aircraft other than the MTOW is the J170's extra 1.5 metres span.


Both aircraft have identical, comfortable and very roomy fuselages with considerable storage capacity behind the two seats.


Both aircraft have wing tanks with a maximum useable fuel capacity of 130 / 135 liters.


Both aircraft use the 4 cylinder Jabiru 2200 85 hp engine which at 2950 to 3000 rpm will cruise at very close to 100 knots.


The new $58,000 LSA certified factory built J120 has a smaller cockpit which is an almost identical cockpit to the older Jabiru 55 series but has a much longer fuselage than the 55 series to give much better and easier and more pleasant handling in the pitch and yaw.


The span is 8.16 metres or almost identical with the J160.


The MTOW is 500 kgs.


The useable load is 235 kgs and there is a small amount of storage space behind the seats which is mostly occupied by a 65 litre fuel tank.


The engine is again the same 4 cylinder 2200 series 85 hp engine which due to the smaller fuselage cross section enables a cruise speed at 2950 to 3000 rpm of very close to 105 knots.


Fuel consumption for the 2200 engines at 3000 rpm is close to 15 ltrs / hr.


Depending on your financial circumstances, if finance is limited and whose isn't, and luggage capacity is not a requirement nor over 3 hour duration legs and personal size ie; fat buggers like me! is not an issue then the J120 is a must look at.


If range, luggage capacity and personal comfort is needed then the J170 would be my first choice, not the J160 and I will confess here that I am heavily influenced by my gliding experience when it comes to comparing short span perfomance to long span performance.


Long span comes out on top every time in just about every catergory except aerobatics.


We also have two beautifully and locally kit built J170 and a J230 in our hangar and new Club owned certified J120 and a certified J230 glider tug/ trainer / xcountry aircraft.


I have based my comments on our experiences with these aircraft.


Have fun and may your choice give you great pleasure for many years ahead.



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Thanks Fellas,


Apprieciate your 2 bobs worth Phil, Blueline and Rom. The J120 sounds good but i'm 6"2 and take up a bit of room. I'm a stock agent in the NT and am looking for something that I can do a bit of crosscountry in with a passenger and a little bit of gear. Speed is not as important as range. I've had a Drifter in the past and it was a great machine for station work but not much good for traveling.


Being a bit isolated I don't know much about other types that might suit what I'm looking for so any suggestions are greatefully recieved.


Cheers Rick



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G'd evening Ricke.


Can you lay down a few criteria that you would like or have to have in your ideal aircraft.


1 / A large cockpit is needed as you are tall. You need to accommodate another person for quite some time in between stops as you say that range is important.


You will no doubt as is the case with all stock agents, need to carry a bit of luggage and a lot of essential items that only stock agents know the mystery that lies within plus what items your clients can talk you into delivering to them.


2/ I would assume that you sometimes land in some pretty rough strips and areas which will need a high wing aircraft for clearance plus the high wing has a good shade effect in strong sun conditions while flying and on the ground!


3 / You need very good short strip abilities plus slow flying on occasions to inspect or find stock and you also need an excellent all round view if you can get it for the same reasons.


4 / Very good range is needed.


I would seriously suggest that you look at the "Foxbat" from Silverwing Aviation ;http://silverwing.com.au/2007/


A station owner from central NSW brought their Foxbat down to Horsham for a couple of days early this year.


A couple of our guys flew it and were very impressed with the handling and flying qualities.


The build quality is really excellent. The amount of room in the cockpit is huge.


The view out is really superb.


The station owner told us it was a superb aircraft for his purposes with it's slow flying, excellent lookout and it's short and rough field characteristics but still with enough range and speed to go places.


Two strikes against would be it's imported status and I don't know the quality of the agent and the light wing loading that gives it the short field, slow flight characteristics but will also give a rough ride in the strong thermal conditions of the north.


If price and local serviceability and price are a serious problems, I would suggest that the next best option will probably be the J170 but you will sacrifice very slow speed handling, good all round view and will need a longer T/O and landing areas but the simplicity of the maintenance of the J170 will also be an advantage.



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I tend to agree with you Motza. 15l/h at 3000rpm is a bit light, more around the 18-19lph.


Yours should rev to 3000 though unless the prop is overpitched or tacho is under reading....


I normally see about 2900 on climb at 70knots IAS and it'll rev way past 3000 when I level off...







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To make sure that I aren't wrong, I'll check with our guys who flew the J120 [ 2200 hydraulic engine ] back from Bunda-ru a couple of weeks ago but I am fairly certain that their fuel record came out at very close to 15 ltrs / hr and they cruised at the 3000 rpm setting as instructed by Jabiru which gave them very close to a 102 to 105 kt cruise.


I will also check with the J170 owner [ 2200 hydraulic ] engine just to make sure of my facts and get back here whether I am right or wrong as fuel consumption info like this can be important for nav purposes or even maybe for picking up an unsuspected problem in an engine.


The fuel consumptions of 22 L /h that you are talking about sounds more like it is getting close to the 3300 6 cylinder's consumption figures.


We are having problems with low power output from our hydraulic lifter 3300 engine in our J230 but that is being looked at.


The kit built J230 with the older push rod engine and standard prop kills it in the climb even though the Club J230 has a climb prop for glider towing.


Using the same prop from the kit J230 on the Club J230 merely increased the performance gap between the two aircraft.


The J170 had an engine pushrod failure in the first 13 hours and was replaced.



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Mozartmerv, we are hearing quite a few reports like yours and as you have read above in my post, we are experiencing some similar engine difficulties.


There appears to be some very large differences in performance between what should be identical model engines.


Our own experience with the propellers supplied by Jabiru as towing props were not very confidence building in their propeller quality control.


Apparently the wrong configuration of the towing prop was supplied to us.


I won't go into details but a new prop has been supplied after much moaning and bitching on our part.


One item should be very carefully checked and that is to measure the chord width at various identical stations along each of the blades to ensure they are identical.


Our original props weren't.


The chord widths were up to 4mms difference between blades and you can imagine what that did to engine vibration and prop performance.


The new prop performs a lot better and further developments and improvements are in the pipeline.


We are coming across some examples of supposedly identically pitched props which seem to show large differences in actual performance.


We are starting to suspect that very small but very significant differences in the props may be the reasons for the differences in prop and therefore apparent differences in engine performance.


In WA, a Jab owner found that as little as a millimetre off the trailing edge of the prop blades made a substantial difference to the revs and power output of the engine and he eventually added to and then removed very small widths at the trailing edge of the blades to achieve the performance that he was looking for from both engine and propeller.


So as a suggestion, why not do a small trade as in a few beers for a swap with another prop from a well established good performing aircraft to do a performance trial on your own aircraft.


You would eliminate or confirm a potential engine performance problem and get closer to the reasons why your engine is not performing the way you would expect.


If, after this test you know that it is the engine at fault then that is where you have to look to solve your problem.


The Jab engines are remarkably simple but tracking down a problem in any engine that appears to run OK can still be very frustrating.


A quick edit; Your revs and fuel consumption sound similar to the local J170 when it was fitted with a 44" pitch prop instead of the standard 42" pitch.


The owner hoped for a higher cruise speed but it was hardly any better in cruise, gave a frightening lack of climb in the owner's words and the engine never got above about 2850 rpm. The 44" pitch was just too much for that 85 hp to drive.



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Thanx guys..i'll have a chat to the engineer about all that.. You guys that get 15 l/hr at 3000 rpm, did you do the recent fuel jet mods??..I noticed an increase in fuel burn after the mods were done..Another thing is the engine isn't rated past 3000, that is it redlines 3 grand, and the static rpm we check during take-off roll is 2850 +- 150 rpm..And thats what is in the checklist book as well...so mabye there's something going on im not aware of ...


cheers fellas:thumb_up:



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motzartmerv; I checked this arvo on the fuel consumption in the J120 and the J170.


The J120 averaged around 14.86 ltrs/ hr at a cruise of 2950 to 3000 rpm and an indicated A/S of 103 to 105 kts for the trip down from Bundaberg and this is with a brand new and tight motor.


The J170 is averaging a similar figure.


Both engines would be only a few weeks since being built so will have the latest jets in them.


I have given some thought to your high fuel consumption.


You obviously cannot get max revs as your engine is running far too rich a mixture so possible problems are carby related.


Try to lay hands on another carby and install and run a few trials to see if the carby is the problem.


Starting from the simple fixes first;


Check engine tuning bulletin JSB 018-1 on the Jabiru web site.Tthis shows a detailed cross section of the Bing carby on page 4.


1 / Choke is partially closed due to misadjustment or a carby component not installed correctly.


2 / Float level is not correct which can allow very rich mixtures.


3 / The Bing is a diaphragm carby that automatically adjusts the mixture through the means of a spring loaded diaphragm moving the main needle up or down to vary the fuel flow to match the outside air density.


If the spring is distorted then an incorrect mixture will be fed to the engine.


If the diaphragm is distorted or punctured, like wise.


4 / Is the air density sense port blocked?


5 / Is the idle jet correctly seated as it may be allowing a large fuel flow past a loose or unseated jet.


I would suggest that you isolate this problem sooner than later as excessive fuel useage has the effect of the unburnt fuel washing the oil film from off the walls of the cylinders as well as leading to crankshaft oil dilution which leads to rapid wear, a short engine life and lots of unnecessary expense plus the possibility of some nasty, loud and unwanted and non harmonious noises emanating from the vicinity of the engine at some time in the future.


It is doubtful that you will find the reason for the excessive fuel useage in any other engine component as something like a cam shaft being a tooth out in the timing would have a very serious effect on the overall engine performance.


Edit for a further thought; Has the air inlet to the carby been checked from start to finish for blockages particularly when the engine is running as I have seen collapsing intake pipes choke an engine right down but appear ok when the engine is stopped?



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My 160 revs to 2900 on climb out at 65, 70 or 75 knots. :thumb_up:


Motzartmerv, I'm pretty sure that Jabiru quotes the 2200 - 85hp @ 3300rpm. ;)


I have changed the jets as per the latest Jabiru instruction. :big_grin:


I know of a 160 that has the 44in prop and still revs out OK. :)





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Rom, thankyou for your detailed replies.. I am flying on tuesday for my instructor endorsement test so i will take all this up with the chieff and the engineer.


I guess my main question is pehaps the engine is derated somehow, i know that 3000 rpm is full throttle and burns in exess of 25 l/hour and goes over 1:1 on the tacho/airswitch..It may be the prop as you said ealier, i have noticed on warmish days and heavy loads that the climb performance is quite poor, to the point where i have been in thermals at full throttle and at max rate attitude and still descending at 300-400 fpm.. So im starting to think its the prop.


I will pin the chieff down to some answers on tuesday..


We have 2 jabiru 160 c's at the school and both have pretty much ident performance and burn rates.Typical figures would be, 2700 rpm, burn rate 16 l/hr, and IAS of 90 kts..


Bigpete, yep ive seen the documents quoting 3300 rpm as max rev's, but jab 4785 could never get over 3000 rpm...But the thing is the EMS shows the red line at 3000, and the flight manual states 2850 +- 150 rpm as max static rpm...Me confused now as to what the differance is between our engines and the ones you guys are running..


Thanks again for your input , its greatly appreciated..





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ROM .. re 3300 power. I recall seeing mention of lower power output on hydraulic 3300 engines on a US Jab web site. They reported that it had been fixed by Jabiru changing the cam.


Hope this helps.


... Vince



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Maximum STATIC RPM. Important point as that is the max revs that the engine should be able to achieve when running up on the ground with the correct propeller for the engine. [Generally needs to have the aircraft tethered to do this without dragging the wheels. ]


A Jab 2200 with a static RPM of 2850 should give you around 3250 to 3300 when flat chat in level flight.



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VME, Yep, we have been aware for some time that the cam profile was being changed in the later production hydraulic lifter engines.


The power increase in the 2200 engines with the new cam on the dyno is only about a reported 1.5 KWs or thereabouts so nothing spectacular but useful.


The 3300 engine was just going on the dyno about 3 weeks ago for testing so some of those overseas reports were a bit premature.


The last of the pushrod engines are probably still above this power rating although I don't have comparative figures.


Poor or limited servicing of the valve clearances on the pushrod engines would negate any power advantage very quickly.



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Interesting ROM.. Perhaps our engines would rev out to 3300 but that would be way over the red line...So that brings me back to the fuel flow difference..I don't know what 3000 rpm would burn because i never get it up that high in the cruise..And as i said 2700 gives us about 16 l/hr..Looks like im gunna be on the phone tommorow...ill ring Jabiru and aslo the owner of the aircraft..He owns a heaps of jabs in sydney, has a business called leaseair..Hes a nice guy to, i spent some time chatting about a few things the other day, he's a qantas heavy captain...and very knowlagable on the jab's..


cheers again for the tips lads..



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Your aircraft is not a certified VH registered by any chance?


If so, maybe a derated engine for the GA registration to guarantee the service life.


Just asking!



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Guest brentc

2700 at 16 lph is acceptable given that your aircraft would have had the needle changed to the higher fuel flow. You may also have a slightly in-accurate tacho.


Some if not all of the Leaseair aircraft have been modified for increased cooling because of some issues that they experienced when operating out of Bankstown (engine failures if you recall), so without a doubt, your aircraft is running a little richer than some others, but this is no doubt a good thing because it will guarantee your valve life. Realistically, the more fuel burn the better when it comes to prolonging the life of your engine (within reason of course).


I've not heard of Jab engines being de-tuned before so unlikely to be the case. The GA LSA Jabs and RA LSA ones are one in the same.



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