J160 J170 reality.

[Ultralights]

I am researching my next aircraft purchase, and i have recently been looking at the J160/170 series aircraft, now looking at the Jabiru site and info, i have found a few anomalies, and would like the real world Honest numbers from owners...

 

for the J160

 

Cruise Speed @ 3050 rpm 100 knots

 

Engine Jabiru 2200cc 80 hp Propeller 2 Blade Fixed Pitch Wooden/Composite 60” dia x 42” pitch

 

Wing Span 8120 mm

 

now with the J170...

 

Cruise Speed @ 2850 rpm 100 knots

 

Engine Jabiru 2200cc 80 hp Propeller 2 Blade Fixed Pitch Wooden/Composite 60” dia x 42” pitch

 

Wing Span 9657 mm

 

 

 

now, as you can see, the J160 cruises at 100 kts at 3050 rpm, yet the J170 will cruise at 100 Kts at 2850 rpm, yet is has an identical prop and pitch, yet it has 1.6 mtrs more wingspan,

 

 

 

i would assume that 1.6 mtrs of extra wing, would add a bit more drag, and lower the cruise speed somewhat, yet it has equal speed, at lower RPM than its small winged counterpart...???

 

 

 

so what i am after is some real world cruise speed comparisons from J160 and J170 Owners and pilots....

 

 

 

 

 

[motzartmerv]

G'day ultralight's.. Ive only flown the 160.. I have flown 4 different 160's and have never got 100 kts out of any of them.. 90-95 is a more realsitic sort of cruise at about 2800-2900.. but our jabs redline at 3000 so we tend to bak off a bit in the cruise..At 2800 rpm we are burning about 22 l/hr..

 

Now.... Im sure a heap of guys are gunna jump on me here and say nah nah, i get 100 kts out of 15 l/hr... ive heard many guys say this on this forum but am yet to see it..in 4 different 160's..

 

I agree with you, those numbers don't make any sence.. I believe (please correct me if im wrong) that the 170 is the same fuselage and cockpit as the 160, with the 230 wing on it..

 

cheers

 

Ps..have you flown the 160 or 170 yet?

 

 

[BigPete]

OK - Here we go.

 

The Jabiru 4 cylinder redlines at 3300. (and can, just like the old VW, run at this redline all day (at around 28 liters an hour). :thumb_up:

 

My J160c without spats will easily do 100 knots at 3050 revs. (and it loves it :heart:)

 

(16 liters an hour)

 

The J170c does more or less the same (2 or 3 knots difference, maybe) at the SAME revs.

 

The J170c also has a wider (300mm) elevator as well. It is also (if factory built) LSA which means a max take off weight of 600kgs against the J160c's 540 kgs. :thumb_up:

 

The J170c also costs about $5000 more to buy. :confused:

 

Have a real good look at the J120c - it's a real blast.

 

:big_grin::big_grin::big_grin:

 

regards

 

 

[Guest Pioneer200]

Re J160c and 100 knots, yes our club plane will cruise at 100 knots at rpm of 2900 and burn approx 15 litres an hour

 

 

[Guest J430]

Some props are better than others..... a number of us have found the subtle variations!

 

Also check your TACHO v and optical tacho. Sometimes they need calibrating. Ours was 200 RPM out!

 

 

[Adrian Lewer]

i have flown both and find the J170 to be a pain in the bum for me. the J160 flies where you tell it and will land great for me, the J170 was designed to aid Novices to land a bit better which it does but this is the problem.... the J160 i can pick a point, hold the nose down, pull the power back whilst leveling off and she sits down nicely for me but the J170 will just keep going, going, going,going...... and going..... which i suppose is great for people who hold off to early like id did when i first started flying in an LSA, the J170 also slows the base leg down by 10Kts. i have found the J170 likes to cruise at full flap at 60KTS where as the J160 likes 70 Kts. i have had the J170 down to 50KTs (hope manny does not read this :) ) and it was as solid as a rock i thought i could even slow it down more but thought did not want to become another satistic. the J160 becomes very slugish at this speed for me.

 

i would buy a J160 if i bought one but if it was for a flying school a J170 is great, very forgiving.

 

just my observations having flown both..

 

 

[kevinfrost]

I'd say the 160 would be the novices a/c going by Adrians assesment of the 160 & 170. The skill of point and go with few inputs would be inferior compared with many imputs and in most cases quicker reaction times required for the later. The float situation is not unlike the difference betwee the 172 & 150 Cessnas.

 

We were considering a 160 then a 170, after taking into consideration the time we could allocate for building and economics of building and running the a/c the J120 won out. We've just got rid of our taildraggers:crying: and have flowen the 160 and found it to be a slug on climb out & in circuit. The 120, crisp and quick,:thumb_up: a kid could fly it. There goes the skills, every time you pin a crosswind landing and get it right in a taildragger you feel like you've achieved.

 

 

[Guest Bendorn]

I've only ever flown a J170 so I cannot compare it to anything else. BUT, it is a very easy plane to fly.. I was cruising about today doing a comfortable 100 knots at about 2900rpm.

 

As Adrian said, she's a very easy plane to land. I tend to hold a little early as I like that long gentle touch down just as the stall starts screaming at me.

 

I'm itching to fly the J120. I've heard nothing but praise for this machine. Can't afford one on my own, so I'll end up with a nice little 55LSA by the end of the year...

 

 

[Geoff]

You can try the J160 at the flyin Ben

 

 

[Adrian Lewer]

the LAS will fly the same as the J120, (virtualy the same airplane). i done 8 odd hours on the LSA's. will not handle the bad weather as well as the J160/J170 with the little rudder but the climb out is better.... much better.... i like the J160 because it does what you tell it to do, has the room for luggage ect and has all the mod cons (i like gadgets :) )

 

with regards to buying a LSA you will pay around $40K for one with 2000 odd hours on the clock. might be worth buying a J120 for $58K if you can save the rest. i know of someone who bought a 40K LSA and was unfortunately burnt and needs about 10K work to bring it up to a .......... much better state shall we say so worth the extra 18K in the end... as well as the fact you have a NEW aircraft, only downfll is you get the basics and you cant install a xponder so you cant go into controlled airspace if you had an endorsement...

 

kevin remember the J160 is much bigger this is why the J160 is more of of a slug but flies much better in my opinion (remember we all have different flying styles and wants ect i just like being in the air) J120 great training A/C but the J170 is 100% better for training... you can almost pancake it onto the runway..

 

was flying the J170 today with 25 Kts 360 degreese done my PFL's and flapless aproaches with it and was great but would still prefer the J160.

 

oh and donkey dont fly the 2.2 at any less than 3000 in the circuit or x country as you will glaze it up and reduce the life of the engine.

 

bendorn that is the best landing style IMO as the stress on the u/c is reduced and you have less skating if you touch down whilst greasing it on, and i like the sound of the stall warning :)

 

 

[Adrian Lewer]

oh ultralights as per your question the J160/J170 have about the same cruise speed at 3000RPM of around 105-110 KTS indicated..... the only real difference you will see is on the landing... J160 drives in at 70KTS the J170 floats in at 60KTS.... as for flying the two about the same...

 

 

[Guest brentc]

For a flying school environment I would DEFINITELY NOT buy a J160 if a J170 is available to you and within your price range.

 

The J160 is not 600 kg's like the 170 is and will limit your legal passenger / student carrying capabilities, it won't climb nearly as well, uses more runway when taking off and landing. The J160 will struggle on hot days to maintain a safe engine temperature that won't limit the life of the engine and you might get 300fpm out of it if you're lucky and you may end up with 500 ft circuits to keep it cool - this is a common problem Australia wide in the higher temps, even in Vic. The engines simply don't last at the higher operating temps.

 

Private ownership = J160 or J170.

 

Flying School = J170.

 

For those that think the longer takeoff and landing won't make a difference, I know of a school that spends over $5,000 per annum on Jabiru tires and it does make a difference to operating costs!

 

 

[motzartmerv]

For sure.. The 160's big downfall is its climb on a warm day.. Flew one up to rockhampton in qld at chrissy and had some real problems maintaining alt in places.. even at full power and climb attitude she was getting 500 ft/min in the wrong direction ie...DOWN...

 

 

[Geoff]

Onya Kev way to go

 

 

[slartibartfast]

Congrats Big Kev. You're excited!

 

 

[Yenn]

I don't care how fast they go, but a minimum safe speed of 50kts seems a bit slow. I would have thought that a 100kt plane should be controllable at less than 50% of cruise.

 

 

[Guest Carl Booth]

J 170 Aerodynamics

 

Got a chance to try the 170 at Maitland recently. During my first landing approach, the 170 floated endlessly in ground effect, until the frustrated instructor grabbed the controls and gunned the engine ! Very embarrasing for an old pilot like me with over 30 years experience. I'd really got used to "floating" with my low wing SV-2 Vampire. But this is a high wing plane ? That airfoil surface must be beautifullly smooth, and "sophisticated', as it takes ages for the flow/lift to bleed off. No wonder some of the hardened pilots there at Maitland were not all that anxious to take the 170 out for a spin ! Like all are saying, the 160 does what you tell it to do. And of course, the Gazelle is much more enjoyable to fly for the same "sohisticated " reason. Cheers Carl

 

 

[Ultralights]

so far all points to the 170, even though i keep hearing the stories of, it floats forever! then how about beginning flare at 5 kts less??

 

I also like to visit a few places where the strips arnt the smoothest,or the longest, so the slower landing speed of the 170 would be ideal, and put some big tyres on it, and it seams like it would be a very capable bush aircraft..... i know for a fact the jabs are solidly built... though it will be interesting to read Kevs reports on his new 170 when it arrives!!!!

 

 

[Steve Donald]

the 170 has a larger tail plane as well as wing, it fly's with less angle of attack , more nose down and due to this it is actually a little faster give Mick Chapman a call he operates both aircraft at his Flying Centre in Murray Bridge SA, he is VERY EXPERIENCED WITH JABIRU AIRCRAFT, and will be happy to assist with information in relation to performance and maintainence issues, this will help you to make a sound decision, good luck with your purchase cheers.

 

 

[Guest cbcyclist]

Hi,

 

I'm new to this forum, my first post actually. I flew a J170 in Tennesee last December for an hour. Found it had no problem cruising at 100kts no hands straight and level. It did like to float a little on landing but nothing to be bothered about. For me it was the most comfortable plane I've ever flown.

 

I'm in the process of working out financing to purchase it. For some reason in the USA folks don't seem to want the 170. The factory demonstrator has been on sale since last fall. Are they popular in AUS?

 

Chris

 

 

[Guest brentc]

Hi Chris, it would seem that in Australia that the J170 is the pick of the bunch for 2 seater Jabiru's. It has the best of everything that Jabiru has ever produced in 2 seater form, such as roomy interior, large dash, wet wings, adjustable pedals, latest engine, reasonable good looks, higher speed cruise, excellent climb, shorter takeoff and landing and a price that's not ridiculous.

 

Compared to other 2 seater Jabiru's the only down sides that I can think of are the slightly bumpier ride due to increased wing area, it's slightly larger in terms of wingspan which may make hangaring an issue, the float which is very easily overcome and I can't think of much else.

 

We'll probably see soon (if not already) that the J160 simply won't be offered for much longer and the J170 will probably become the minimum spec. With J160's climbing at as low as 200-300fpm in the Australian summer, I can't see them continuing with this model, or atleast not in a training environment anyway.

 

 

[Guest ROM]

I agree with brentc.

 

We are all shaped by our experiences so take that into account and make the necessary allowances for bias when you read my opinion.

 

As an old glider pilot I will just repeat the gliding adage; There is no substitute for span!

 

When the word got around that the J160 was to be certified, I had a couple of conversations with a RAA flying school proprietor who has an excellent rapport with Jabiru and was keen on getting a J160.

 

I expressed my strong opinion [ not unusual as my mates will tell you! ] that Jabiru were making a serious mistake in certifying the J160 instead of the longer span J170.

 

I was also told that the J170 would never be certified due to cost after certifying the J160 which would fullfill all the training requirements.

 

Well the J160 was duly purchased and although nothing was said I eventually heard on the gossip machine that there was some disappointment in the performance of the J160, primarily due to it's lack off climb performance during training and in hot weather.

 

Well, despite the original denials, the J170 was quietly certified and the RAA school acquired a J170 to replace the J160 which he is now very happy with.

 

We have a kit built J170 at Horsham.

 

The proud owner is very happy with his choice.

 

Big cab with lots of room for two big persons and some luggage.

 

Good cruise speed around the 100 knots but not quite as quick as our J120 due to the smaller cab cross section of the J120.

 

Long range.

 

Short take off compared to other Jabs and good short landings but not short field landings.

 

The long span J170 has a lighter wing loading at the same AUW which means it gets off shorter, lands slower and shorter, stalls slower, has a better glide giving more choices and time if the dreaded silence appears up in front.

 

If you make a mistake and get yourself in a sudden nasty stall type / spin situation, the high wing loading and shorter span of the J160 will really bite when it lets go and will cost a lot of height whereas the J170 with the lower wing loading and longer span will not be anywhere near as nasty in it's reaction.

 

Only disadvantage with the J170 would be a marginally rougher ride in turbulent conditions.

 

Of course if you could only put a 3300 6 cylinder 120 hp engine in a J170!!

 

Then you would really have an aeroplane which would leap off the ground, climb like a homesick angel and go like a cut cat and still out-range most stuff around.!!

 

Personally I would not even contemplate a J160 but as I said, I am shaped by my experiences with long spans and the need to always think ahead as you only get one go in a glider.

 

 

[Guest brentc]

To add to that, technically the J170 wasn't certified like the 160 was in 95.55 CASA registration, so technically true to their word Jabiru didn't actually certify this aircraft, however they did certify the J170 under LSA which cost near to nothing in comparison! The J120 is the same, self certified under LSA so no great cost there either. It's good to see LSA manufacturers taking advantage of the rules that were invented for them which was intended to level the playing field and make new aircraft more affordable. Affordibility was possibly the primary objective for LSA, however moreso for GA schools to lower the costs of their aircraft so as to compete with RA-Aus schools.

 

 

[blueline]

sick of J160 bashing!

 

What is it with normal people and the abnormal hate of the J160!

 

quote

 

"If you make a mistake and get yourself in a sudden nasty stall type / spin situation, the high wing loading and shorter span of the J160 will really bite when it lets go and will cost a lot of height whereas the J170 with the lower wing loading and longer span will not be anywhere near as nasty in it's reaction."

 

Oh please! - I have in the course of my work seen people try every kind of power on/ power off/ flaps down/ flaps up/ turning/ pitching/ rolling/ accelerated/ non-accelerated/ crossed up stall, with all kinds of inventive recovery techniques and I have NEVER seen one "bite".

 

AND, while I am having a rant, HOW DARE these up start J120 people compare themselves to the J160! The J120 is cheap and it climbs better. From there on it is down hill......

 

 

[Guest ROM]

Told you I was an old glider pilot so not to be trusted :thumb_up:

 

Nothing wrong with the J160.

 

I was merely expressing my opinion in that I believe from what I have experienced in gliders, tigers, austers, chipmunks, pawnees and etc, that there is a better choice in the Jab line for most pilots than the J160.

 

Modern aircraft are good in their lack of bite but they, as in all aircraft will bite and bite hard when you get the combination of flight characteristics just right and anybody who does not believe this may, if he / she are unlucky, find this out to their deep and possibly short lived regret.

 

Most pilots will never get near those limits but every now and then somebody does.

 

Usually they wipe the brow and fly on without knowing how close they really were to coming thoroughly unstuck.

 

At other times somebody has to come along to pick up the pieces when the aircraft that never bites, did!