TIF in a Jabiru J-160, controls, LSA impressions and designs

[marcwolf]

Hi everyone,

 

This is my first post :big_grin: and apologies for a big post!

 

I finally went on a trial instructional flight this weekend that I've been wanting to do for ages, it was in a Jabiru J-160C and was a lot of fun and quite an experience!

 

I've been reading and following aviation for quite a while, been on many flights as a passenger in commercial jets and the odd turboprop, plus some excellent times in the cockpit of 747's and 737's for cruise, landings and takeoffs (before 2001 of course).

 

But I'd never flown in any light aircraft at all, or tried flying one myself, though I'd thought about it for ages.

 

I'm an electronics and computer engineer and like to soak up lots of info, think about and know what's going on with whatever I do, I also ride sports motorbikes, trail bikes, some fun racetrack riding and driving. I've built and modified motorbikes and cars so it's been fun to look at and learn about all kinds of GA and LSA aircraft, the airframe, controls, engines and avionics.

 

Checking out all the light aircraft around I was first surprised at the low-ish cost of them, much lower than the $300K+ I just assumed 6 months ago they all were. It makes it really fun to realise that there's a bunch of light aircraft that I could dream about owning one of myself in a few years.

 

So trying out flying the J-160C was cool. I'm not sure it's the 'plane for me' or maybe it was just the feel of this one, some things were quite different than what I expected! I'd love to get your feedback and ideas about it.

 

For fun and inspiration I've been checking out heaps of LSA's, kit or built to narrow down what LSA I may get in the future, reading RA-Aus magazines and all that.

 

In flight, I thought the J-160's controls a bit like a 70's car with slop in the steering box and some friction and stiction too.

 

Reading many posts about other GA and LSA planes, especially ones with control rods, I was expecting this smooth, tight and progressive feel to the controls that wasn't there. It felt like I had to move the stick some to remove a bit of slop, then push through some friction to get an effect.

 

Is this normal, just a characteristic of simpler control cable rigging setups, or this aircraft type?

 

It's possible I wasn't used to it, being a new flyer and not doing really large control inputs yet, but I'm hoping there are a lot of other LSA models with smooth, tight controls out there. I'm going to fly some other types along the way and see.

 

Some other impressions were, whoa this thing is noisy! You definitely know that you're in a hollow fiberglass shell with a large boxer engine and prop beating at it a hundred plus times a second. My ears were ringing for a couple of hours after, I was wearing a headset of course but probably a cheap one.

 

Near the top of my wish list later is going to be the quietest LSA around.

 

My situational awareness was funny, I knew it was low at times but I was in information overload, focusing on flying, watching airspeed, altitude and direction, etc. There were times where I knew I didn't know where the airfield was, it's great to have an instructor with you keeping an eye on your location, radio and traffic as you learn.

 

Other notes:

 

On this J-160 I noticed the door locking pin at the top of the door is difficult to grip and stiff to pull, wouldn't want to be in a hurry to get the door open and get out.

 

"Composite" for this plane means it's a thin fiberglass fuselage and not much else, not much in the way of internal bracing or frames either but obviously it seems strong enough. I previously thought composite was strong carbon fibre and metal combinations, but I see in this area it can be any mix of materials that's not an 'all-metal' plane, even wood and fiberglass or metal combinations.

 

I was surprised at the roll and pitch movements of the plane with some small wind currents, it felt like you had to 'fly' it a lot to keep it fairly level. I heard later these J-160's are like that, but it does make them a good trainer since they're not totally straight line or 'hands-off' trimmed cruise fliers.

 

Well that's about all for now, I'd love to hear any ideas and feedback from the above rambling questions ;)

 

Cheers,

 

Marc

 

P.S. for later dream aircraft, so far I like the look of the Morgan Aeroworks Sierra 100/200, Sonex, Pioneer 300, Zodiac XL, and CZAW Sportcruiser or whatever it's currently called! Any others? I like the idea of all-metal, low wing, quiet, strong, fast, low stall speed and a BRS. I hope to see BRS available in more LSA's, used appropriately of course. Subjects for another post I think.

 

 

[Ultralights]

gday,,

 

Is this normal, just a characteristic of simpler control cable rigging setups, or this aircraft type?

sadly that is normal for that aircraft type, as you are pushing a cable through curved guides, some aircraft like my Savannah, and many others, are very responsive compared to a Jabiru as their control systems are made of direct rod connections, other types of aircraft can be described as over responsive, or literally needing just fingertip control. The Jabiru series aircraft are best described as , Easy to fly, but difficult to fly well. which makes them good stick and rudder hands on trainers.

Aircraft like the Tecnam series are very easy to fly, and some say create lazy pilots as the aircraft design overcomes the things you have to do to fly a Jabiru, things like adverse aileron yaw. using a rudder etc. eg, in a Jabiru you need to use the rudder to balance your turns, whereas a Tecnam, or similar type, very little rudder, if any is needed.

 

As for noise attenuation, its all about the headset quality, headsets can range from $150 to $1500 for a good Active noise reduction headset which almost totally removes any background noise.

 

Dont worry too much about the situational awareness, in the first say 10 to 20 hours of training, you will find yourself overwhelmed with info sometimes, but once the skills involved in actually flying the aircraft become second nature, then your mind is free to worry about traffic, monitor the aircraft, and keep good situational awareness with regards to Radio traffic, navigating etc etc.

 

 

[sseeker]

On this J-160 I noticed the door locking pin at the top of the door is difficult to grip and stiff to pull' date=' wouldn't want to be in a hurry to get the door open and get out.[/quote']You'll probably have loads of strength to get out after you've landed in a field. I've learned that the pin is there to prevent flex in the door, it also keep it flush with the fuselage (if you ever leave the pin out accidentally you can hear wind coming in through the top).

 

In flight' date=' I thought the J-160's controls a bit like a 70's car with slop in the steering box and some friction and stiction too.[/quote']I think you'll find this with the older Jabirus. My school has two Jabirus (both 160s) however the older one has slack as you describe it, the new one is just stiff to move. However I'm unsure if slack will develop over time (I wouldn't think so).

 

I was surprised at the roll and pitch movements of the plane with some small wind currents' date=' it felt like you had to 'fly' it a lot to keep it fairly level.[/quote']With the Jabiru it's pretty important that you don't overfly it, try and let it recover from the "bump" itself, or just use very small inputs.

 

Best of all, welcome to light flying and I'm sure you'll enjoy every moment of it. The Gazelle and SportStar are also nice trainers and the controls are much more sensitive and you'll probably find them nicer.

 

Safe flying,

 

Andrew

[dazza 38]

Welcome Marc, I enjoyed your first post.

 

 

[fly_tornado]

hi Marc

 

sounds like you had a good flight!

 

 

[Thirsty]

Hi Marc,

 

I'm learning to fly in a much older LSA55 Jabiru and I too had some concerns with the controls exactly as you mentioned. I've done 7 hours now and find I'm not really worried about the control response (or lack of it!) and the effort required to move the controls. It's all starting to become second nature now so if you persevere with the Jab I'm sure you'll get comfortable with it.

 

All aircraft have their strong and weak points. I gave up GA flying in the early 90's 'cause it got boring - those Cessna's are way too easy to fly! I'm finding the Jab is keeping my interest levels way up 'cause you really have to fly the little beastie :)

 

 

[facthunter]

It's information overload on a TIF. Everything is new.

 

Your awareness is good and brings to mind what is desireable in a personal plane. ALL aircraft are massive compromises. The Jab does stand up to a training environment pretty well and has proven to be pretty strong in a prang. It's lively in gusty conditions and you have to fly it "all the way", but not overcontrol it or get very slow. If you learn in it and cope you will be able to handle most aircraft. Keep the weight off the nosewheel.

 

NOISE.. Most propeller driven piston engined planes are noisy. ( I don't regard the Jab as particularly noisy).

 

CONTROL FEEL & RESPONSE. In my view, one of the most important things in an aircraft IF YOU ARE GOING TO OWN IT. If it is a school plane , don't worry about it, as long as it isn't going to fail.

 

Sheet metal construction -- Maybe. The stronger aircraft have a tubular steel frame often or even Aluminium tube (Truss.)

 

You could write a book on this subject , IF you are really interested, have a fly in a PIPER CUB (or similar) and see what you think of that. Nev

 

 

[marcwolf]

Hey thanks so much everyone for the great replies and information!

 

I see what you mean about the cables and curved guides on the J-160, I checked out the kit build manual and they're like oversized, much longer motorbike clutch cables, always going to have some stiction and friction. It's good to hear that the control feel is this mostly just this type.

 

I wonder about lubing, I use a pressure cable lube gadget with this excellent TEF-LUBE oil-and-grease-free spray with excellent results on bikes.

 

Though I do like the idea of control rods better, I think it comes from sports bike riding, I'm used to the really direct and sensitive feel of sports bikes, even at high speed.

 

I'm going to go out and get some more flying time, get used to it, and try some other types too :)

 

Thanks for the tip to not overfly it, I'll really keep that in mind too as I practice. I think soon along the way will be my own active noise reduction headset, I like my good hearing ;) I always wear good earplugs on any motorbike as even there the noise will catch up with you.

 

It's good to hear about the Jabiru's strength and characteristics as a trainer, I'll remember too about the nosewheel when I make progress to landing, cheers.

 

It is some fun to check out the excellent range of aircraft and kits out there while still learning, there's some excellent Australian ones, so nice to see real manufacturers right here in Oz.

 

 

[facthunter]

Controls using rods and self aligning bearings make a plane with the best control feel. The DHC-1 Chipmunk is a good example. Cables on the rudder are OK because it is a straight pull and the cables are unsheathed. The push pull type on the Jab are a market item and do a job. (That is all). The outter cable restraint/clamp has been known to be incorrectly installed and therefore unsafe in that condition. All planes are only as good as the maintenance. (Like M/Cycles). Nev

 

 

[jetjr]

Jabirus are great value for the money - very few say they are the best at everything. They are a very tough aircraft and by far the most popular type here.

 

Yes they are composite, glass fibre and resin, other things can be used like carbon fibre but much more expensive.

 

Regarding controls, a few things here, most have jumped into one aircraft vs another, but Id say the sloppyness you felt is maybe just the way aircraft are, theres no solid link with earth so instant, direct control isnt possible. The faster you go the more effect the control surfaces have. Its also a trade off in design, sensitive controls at slow speed equals difficult to fly steadily at higher speeds. In a TIF you'd be going moderate speed so yeah things would be a bit sloppy especially when it comes time to land and you slow up even more.

 

 

[Gnarly Gnu]

If I can jump in with a related question.... what is the practical effect of full length ailerons or flapperons versus the more conventional aileron + flap like Jabs have? Can I assume that the former would be more responsive, or not necessarily?

 

 

[djpacro]

.... what is the practical effect of full length ailerons or flapperons versus the more conventional aileron + flap ...?

Adding aileron inboard is less effective than one may wish for at increasing the roll rate due to the reduced moment arm. Can be useful at very low airspeed with the inboard end of the aileron in the propeller slipstream.

Drooping ailerons certainly helps with extra flap effect.

 

The implementation of flapperons on the Airtourer was ineffective - for both aileron and flap movement the deflections are very small. Having to reduce the deflections to allow adequate movement of the control as both a flap and an aileron is self-defeating. Seems to me that the Airtourer could've used much more deflection - I don't know why it was limited as it is. In my opinion, the somewhat similar wing on the CT-4 with its conventional ailerons and flaps work much better.

 

..... flying time, must go ...

 

 

[facthunter]

was going to respond last night but no time. The suggested use of aileron and flap in the one function, is NOT a good idea generally in U/L's ,as good aileron response/control is more important than trying to get a more effective flap effect at the same time, particularly at low speed.

 

Adverse yaw with aileron application will be worse, as normally ailerons operate differentially with the "UP" aileron travelling more than the down one. With "flapperons" you don't really get any UP aileron, once you have extended flap. You get the situation where you have drag and More drag. Another feature of the normal set-up. (inboard flaps) is that the extra drag AND LIFT inboard unloads, the wing outboard and therefore less likely to stall first. ( The flapped section of the wing carries a LARGER proportion of the wing total lift.)

 

At first glance the idea seems good and is used in some bigger.aircraft. (The Caribou, I believe), but adverse yaw can be engineered out of larger complex aircraft. ( using coupled differential spoilers for instance) . Some U/L designs that initially used flapperons, had them removed in later models. The mechanism although not rocket science, does introduce added complexity and the possibility of a failure of one side would be the same as with normal flaps but worse in effect as you could not correct with the full aileron capability. I'm not a fan. Nev

 

 

[Ultralights]

the only time i have seen flap and aileron used as one is with "junkers" style flaperons, as there is a substantial gap between the control surface and the wing, effectively a full span slotted flap/aileron. such as fitted to the savannah, 701, Gazelle etc. yet with full flap, there is quite a bit of adverse yaw, as mentioned above, thee is no scope for the up going aileron/flap to create more drag to counter the yaw.