A passengers view

[Yenn]

I flew as a passenger today in a J160 and a J230.

 

First surprise was the poor climb rate of both. In the J160 we both weighed less than 80kg so it wasn't heavy and a good wind down the runway with cool conditions. We were at about 200ft after 700m.

 

The J230 with a lot more horses up front was not much better, although our weight was a lot higher. The pilot said nothing much happens below 90 knots.

 

Visibility in the J160 was poor except downwards and the J230 marginally better as the wing is further aft.

 

Approach in the J160 was normal but the J230 has a glide slope that is extremely flat. I found it interesting to be out 300m from the threshold looking sideways at the tree tops. If the approach had not been clear we would have been unable to land in the first 500m of strip.

 

The views downwards were great and that is something I have forgotten about, but I wouldn.t feel happy in a busy circuit area. Noise was the other area which surprised me, maybe both planes had poor headsets but a long trip would be deafening.

 

The big question is would you consider these criticisms valid for all Jabirus or are these two unusual, or maybe I am biased?

 

 

[Guest brentc]

I'll comment on that, you got my attention!

 

I'm surprised at your comments regarding the J230 and it's climb. The J230 will normally climb at over 900 fpm with 2 pob and reasonable fuel. My J400 with the shorter wings will climb at 700+ with 2 pob full fuel and a fair bit of luggage at around 650kg's.

 

If you had poor climb, without me being in the aircraft, it sounds like the pilot took off without one stage of flap? With no flap it will lift off at around (a high speed of) 65 knots, sit there, do nothing, slowly speed up, then climb. I achieve an altitude with flaps of around 300-400 feet with 2 pob at the 1,000 metre mark, however at that point in time I will have hit near 3,000 rpm, 700-800 fpm and rocketing towards my destination. Flaps I might let off at around 200-300 feet or perhaps a little more after which it accelerates quite rapidly.

 

Even at the quoted 90 knots in a J230 you should have been seeing figures of around 1,000fpm.

 

Climb in the J160 is the exact opposite. As per AusDarren's previous posts you might get around 300fpm at best with max weight on an average day, so that's one of the reasons why the J160 was built!

 

The way in which the pilot flies a Jabiru makes a huge difference. There are people that use no flap for takeoff, or only 1 stage for landing and pulling off prematurely, landing too slow, etc, etc, it's all a matter of a bit of fiddling to work out what gets you the best performance.

 

Interesting you mentioned the flat approach in the J230. I let someone fly my J400 on the weekend on Saturday and he approached at 60 knots and we were extremely flat in the approach. I usually approach for the most part at 70'ish knots or more, then reduce speed for the landing. This gets me quite a steep approach at low rpm, however the J230 does get harder to land in this configuration because it tends to float. Perhaps he was coming in a little slow if you were looking at the treetops! Not the best situation to be in if your engine failed!

 

Surprised about the noise too. What type of headsets did you have? I have a DC13.4 with ANR and an altronics without ANR. To be honest the altronics are probably better than the much more expensive DC's. Just as a matter of interest, what type of aircraft have you been in / flown that you'd say are quieter?

 

 

[Yenn]

brent-c

 

I thought I would catch someones attention.

 

Headsets I cannot remember what type they were and I didn't try to uncover my ears. The Savannah that I flew in as a passenger was quieter and my own Corby Starlet is also quieter. It was most probably a case of poor headsets.

 

The approach of the J230 certainly is a problem not only to me but others have commented on the same thing. I think I would like to have some time in the plane and explore the flight envelope at a safe height. I would expect a slower approach to give a steep glide even if it is getting on the back edge of the power curve would be an improvement. I also suspect that there may be a problem with the ASI reading and the pilot is not willing to reduce below 60kts indicated. We were showing a slower GS on the GPS than I expected. Of course comments by an inexperienced Jab pilot, who was only a passenger do not carry much weight.

 

 

[Guest brentc]

I find that a slow approach gives an unusually flat approach path.

 

I 'fly' mine down at 70 knots at a relatively steep angle. As I was saying, when I let someone else fly her on Sat at 60 knots it was very flat, bordering on tail low angle. The danger in the 230 though is if you come in at 70 knots like I do, it will just float for 300+ metres down the runway.

 

I wouldn't go slower than 60 knots on final. The tail would be hanging from the sky, especially with 3 or 4 people on board.

 

Like you say, a little bit of trial and error would help sort it out.

 

 

[blueline]

J160 performance????

 

This has really got my attention too!

 

I feel like I really MUST comment on your oberservations of the J160.

 

Remember that this aircraft is really a trainer plane and should be seen as a 152 replacement.

 

I have loads of time in both the C152 and J160.

 

The J160 outclimbs a 152 (by a significant margin!), is about 5-10 knots faster and does this on 14-15 lph verses 25 lph.

 

Sure a 152 can land in a shorter distance and at a slower speed, but try getting it off in the same distance!

 

Sure some other RAA aircraft might be faster, some might have more room (but not many), some climb better, some need less runway, some carry more load, some use less fuel, some are cheaper (but not many!) - BUT name an aircraft that is a better allround package?

 

As for the J230 I concur with previous comments - expect near 1000fpm at 100 knots.

 

I dearly wish I could demo to you how a Jabiru is meant to be flown - I suspect that you have witnessed someone flying not as per the flight manual.

 

 

[Guest brentc]

I dearly wish I could demo to you how a Jabiru is meant to be flown - I suspect that you have witnessed someone flying not as per the flight manual.

Actually Blueline, I suspect the problem is that the aircraft was flown AS per the flight manual. The problem is that they quote (for the J230) more in figures like 85 knots (can't recall exactly) as the best climb speed, however everyone knows that 95-100 knots is the magical figure.

 

 

[blueline]

Agree with your comments about the J230 - does seem to thrive on extra speed for the climb.

 

Book figures for the J160 are spot on though.

 

 

[Guest Roger]

After a few adjustments I now run our J230 in on final using similar figures to brentc - 70kts, relatively steep approach and wheeling on at about 55kts. It will float along the runway for sometime if you have any throttle whatsoever.

 

As for climb our machine will easily climb at +700fpm on any day with max load. With just me at a hefty 80kgs and full fuel you can climb out at around 90kts achieving around 1000fpm.

 

 

[Alan]

I agree with Brentc.

 

Our J230 likes 70kts over the fence, it give good authority. Get used to the long float it gives ample opportunity to put it down real gently on the back wheels at about 55kts followed by a controlled lowering of the nose wheel.

 

The climb at 90kts is good for 900+fpm and it enables the temperatures to be kept down ( I have not had the Brentc cowling mods done yet, but intend to).

 

Alan

 

 

[Guest jabgrl]

It's now the 'Jabiru Approved' cooling mods!

 

 

[Alan]

I thought the 'Jabiru Approved' Cooling mods had so far only been adopted as official recommendations for the J160 engine installations?

 

Does not matter much up here at the moment as it has been a real long wet season and it keeps going and going.

 

 

[Guest brentc]

True, I hadn't considered the J160 when I posted that. Hopefully they'll make the little lip for the J230's soon. I would think that cooling mod number 1 would still fit though.

 

 

[Yenn]

This has put the cat among the pigeons. Roger says he has a steep approach at 70 kts. That was the speed my pilot used and it was terribly flat.

 

I don' know if there was a little throttle still on and also it was a homebuilt plane so the rigging may be a bit out.

 

As for the J160 it certainly didn't climb like a C150.

 

One day I may get into another Jab and find it altogether different. I might ven see if I can do my flight review in a Jab.

 

 

[Guest Roger]

This has put the cat among the pigeons. Roger says he has a steep approach at 70 kts. That was the speed my pilot used and it was terribly flat.

I tend to fly a shorter downwind so I am able to glide down final at an angle which lets me maintain 70kts with only a trickle of throttle. I feel much more comfortable this way as I know I can make the runway from anywhere in the circuit. I have witnessed a lot of aircraft flying circuits that would have little hope of getting home if they had engine failure - I dont intend to be one of them

 

On the odd occassion I get too far downwind I do have to drag it home and it does come in relatively flat. I think it all comes back to how people fly their circuit and set themselves for the approach phase.

 

Tell me if I am doing the wrong thing here as I dont have the experience you guys do.......

 

Cheers

 

Roger

 

 

[Yenn]

Roger. You are doing it correctly. I have always understood that you should be able to glide in from downwind and that is my preferred method. If you shut off all power as you turn base and do a glide approach, turning final above 500' you should be able to handle any emergency. Keep a bit high and either slip in or use the flaps late in the approach and no nasty surprises will come your way.

 

 

[Guest J430]

J430 with a less than fresh engine, initial climb out with 50% flap is about500-800 FPM depending on load to 700kg, after that at 85kts I have seen 600-700 in hot conditions and full weight, and up to 1450 fpm with lighter loads and good conditions.

 

70 kts over the fence, or 75 if @ 700kg touching down at 60kts or a bit more if full weight.

 

Beats any C152/172 or chair 'o' key

 

J430