Big tyres on Jabiru

[biggles5128]

Problem- Have J230 and would like to keep the A/C at the farm. I have a strip of about 550 mtrs, the ground not so suitable for a Jabiru. (Ideal for something STOL)

 

Question???? - Would it be feasable to put big balloon tyres and change the prop to a finer pitch in order to handle the terrain and the strip length at 3500ft.

 

 

[Guest Andys@coffs]

Problem- Have J230 and would like to keep the A/C at the farm. I have a strip of about 550 mtrs, the ground not so suitable for a Jabiru. (Ideal for something STOL)Question???? - Would it be feasable to put big balloon tyres and change the prop to a finer pitch in order to handle the terrain and the strip length at 3500ft.

So that question, like all these slight modification questions depends very much on the rego you have. If it starts with 24 then no, and most do .

 

Andy

 

 

[Guest Andys@coffs]

So that question, like all these slight modification questions depends very much on the rego you have. If it starts with 24 then no, and most do .Andy

Actually thats not entirely correct, A finer pitch prop is probably available from Jabiru as a std fit, but it will be only be marginally more fine. The fact that J support it means you can fit it.

Balloon tyres they dont support and are unlikely to ever given that the 230 is a slippery machine (for the type), the J230, and worse J200 wing profile and the word STOL shouldnt ever be used in the same sentance. To take the analogy to an extreme itys the same as putting 4wheel drive mud tyres on a sports car and calling it a bush basher...

 

 

[biggles5128]

Thanks Andy, I hope you didn't think that I was proposing to turn the J230 into something STOL . If it were possible to overcome the red tape legaly, I would be happy to sacrafice some speed for the shorter take off distance.

 

 

[frank marriott]

Problem- Have J230 and would like to keep the A/C at the farm. I have a strip of about 550 mtrs, the ground not so suitable for a Jabiru. (Ideal for something STOL)Question???? - Would it be feasable to put big balloon tyres and change the prop to a finer pitch in order to handle the terrain and the strip length at 3500ft.

Biggles

 

At 550mtrs [i use feet so say 1650ft] is plenty for a J230 at MTOW.

 

I guess you're talking more about surface conditions not length?

 

the strip length at 3500ft. - ? I guess this is strip elevation not length?

 

I operate out of a 2000ft strip and only use less then half but the elevation is only 300ft - I guess the temp. and thus the DA would be the consideration here.

 

Hope this is of interest to you

 

Frank M

 

 

[biggles5128]

Correct Frank, I should have worded that a bit better. Elevation 3500'. I think that the length would be fine even at this altitude however the surface would degrade the performance on take off.

 

 

[frank marriott]

DH and surface is certainly where the answer is.

 

 

[biggles5128]

A couple of things, a 35 deg day in Glen Innes is a rarity....Unfortunatly P charts for the Jabiru are a bit of a non event. Having flown both, the J230 does not need the strip length of a C172 either........Thanks for the replys. I supose I could spend a fair bit on the strip surface to achieve better performance.

 

 

[frank marriott]

Before I spent any money of the strip surface (which is always a good idea), I would be checking how much strip length you really require at MTOW on an average summer day in Glenn Innes. There must be some information available from Jabiru to do that calculation, and if not how did the aircraft gain certification. Maybe a J230 is not all that suitable for that 550M strip, but you wont know if you don't do the calcs.David

David

 

The length on its own is not a problem - the DH is the consideration - My flight manual is in my aircraft and not with me at home so I cannot coment until I get the chance to refer to it [it does have P charts].

 

At MTOW a J230 will outperform a C172 - 120hp at 600kg V 160hp at [about double] the TOW - I forget the actual weight and my notes are not at home with me but I seem to recall about 2800 lbs [round figures that would be 1200lg]

 

I am not aware of the DH problems that may be relevant to Glenn Innes, but at ISA the J230 will eat a C172 - all be it with 2 POB as against 4 POB with limited fuel.

 

Horses for courses - I gather "biggles" is only after opinions - and he has achieved that.

 

I hope my comments are informative and not critical as I fly both [and others] and although I own a J230 I am not promoting it as the greatest - it seems to fit performance with my limited budget.

 

Frank M

 

 

[frank marriott]

Agreed Frank that is why I mentioned the summer temps. I don't know the answer, I am just trying to warn of the dangers of short strips at high DAs. Glad to hear ther are P charts, I was worried for a moment.David

OOOPs

 

Went out to my plane today and looked up the flight manual - what I remembered as P charts in the back of the flight manual was in fact W & B charts. Sorry.

 

Only ref. to take off performance is - 350mtrs on paved surface at seal level in ISA conditions.

 

I obviouly haven't been on a strip short enough to give concern to the J230 or I would have remembered.

 

Frank M

 

 

[Guest Andys@coffs]

I reckon if you search this site for fabiru performanc charts there was a buch of South African data which while not formal and not released by J did provide what you are looking for........really a question of having found them, what can you do with them given where they come from and who supports them.....

 

 

[frank marriott]

Frank, then I would suggest a 550 metre grass strip at 3,500 ft on a warm day would be problematic for a J230.David

No arguement from me there - I just thought my flight manual had P charts, obviously not. For that matter I thought ALL manuals had P charts.

 

Frank M

 

 

[bushpilot]

My private strip is 600+ m grass at 2,900' elev. I land and T/O Jab 160 and 230s there - with no problems - and it is a one-way strip with no go-around option (high ridge behind). I land in the last half of it, so dont have to taxi too far on uneven ground; T/O uses about 2/3rd in nil wind and MTOW. So the Jabs are pretty versatile. (And, no, we dont do instruction out of that strip! - just the occasional demo with students..)

 

 

[bushpilot]

So Chris, if it is a one way strip, I guess your insurance won't cover you in an accident because it does not comply withe requirements of an ALA (airplane landing area). To be legal you must be able to go around. The only people exempt that requirement are appropriately qualified AG pilots.I hope you are not endorsing that RAA pilots should use one way strips. I take it you are a fairly experienced instructor and therefore more skilled than the average RAA pilot.

 

When quoting your above performance on your strip were they at MTOW and what was the air temperature or density height.

 

David

Hi David,

 

No, not endorsing use of one way strips. As mentioned in my post - MTOW; variable air temps, but typically between 10C and 20C. Measurements of 'half' or '2/3rd' are deliberately imprecise, to take account of a range of conditions.

 

In general terms a strip of this configuration is not difficult for a/c like Jabs. - for experienced pilots. I've had C172 and other 'heavies' in here as well..

 

Cheers

 

Chris

 

 

[ianboag]

One takes the points about big tyres on sports cars and all that .... but

 

I like my J160. It has excellent viz , plenty of room and is pleasant to fly. It's a bit slow off the ground though. So I have changed the 60x42 prop for a 60x40. Takeoff feels better (nothing scientific). I didn't really lose anything at the top end because I always used to cruise 95-odd knots at 2800 or so. Now I do it at 3000 which the folklore all says is better for a Jab engine anyway.

 

Now I'm wondering about a 62x36 - same engine load as the 60x40 but more takeoff thrust and 5-10 knots off the top end. I don't mind the top end loss. I used to have a C172A which was working hard to get over 95 knots.

 

I am wondering about some fatter wheels so I can use it easily in places where the surface is not so flash. It will never be a 701 but it will be happier on rough ground. So if some big wheels turn up for a 230 I'd be interested to know the source and the cost .....

 

Horses for courses. Nothing venture nothing win. Old men's toys and all that. So what if I have a sports car with Desert Duellers on ...

 

IB

 

 

[Guest Andys@coffs]

In which case we go back to the rego number. 19= go for it, 24 = only if J will support it and that requires them to issue paperwork to that effect....

 

 

[ianboag]

In which case we go back to the rego number. 19= go for it, 24 = only if J will support it and that requires them to issue paperwork to that effect....

True. Less of an issue here in NZ. It's just a mod that I submit to the equiv of RAA which they will be quite reasonable about. The prop change was a non-issue. Even though ZK-BGY started life as an Adelaide Soaring Club 24-xxxx :-)

 

 

[Guest Andys@coffs]

I flew from the ASC strip at Gawler for many years prior to moving to the the east coast, which XXXX was it?

 

 

[ianboag]

I flew from the ASC strip at Gawler for many years prior to moving to the the east coast, which XXXX was it?

4925

 

 

[Guest Andys@coffs]

That'd be the one I got my 3 axis endorsment on, a J160 that was replaced by a 170 as I recall....A 160 can struggle 2 up in summer at Gawler....

 

Andy

 

 

[nong]

So Chris, if it is a one way strip, I guess your insurance won't cover you in an accident because it does not comply withe requirements of an ALA (airplane landing area). To be legal you must be able to go around. The only people exempt that requirement are appropriately qualified AG pilots.I hope you are not endorsing that RAA pilots should use one way strips. I take it you are a fairly experienced instructor and therefore more skilled than the average RAA pilot.

 

When quoting your above performance on your strip were they at MTOW and what was the air temperature or density height.

 

David

AIRPLANE LANDING AREA Huh? What is this. American spelling. Are you trying to quote FAA regs? LOL

Are you reminiscing about the previously defined DCA AUTHORISED LANDING AREA? Are we time warping to 1968?

 

What are you talking about? What requirement are you referring to? I would be interested to read the legislation if you can quote it.

 

 

[nong]

This CAAP serves to support my point.

 

The second sentence states "There is no legal requirement to observe the details set out in this publication.".

 

CAR 92 (1) is deliberately non-prescriptive, so, if no-one out there can point me to a rule against a light aircraft pilot using a one-way strip, then we must surely be agreed that there is, indeed, no problem.

 

It is up to those in charge of the operation to decide what is a suitable place from which to operate. Simple! So, if a one way strip is judged by those conducting an operation as being suitable, thats it. They are good to go.

 

On a practical note, there is no reason a moderately switched on pilot can't use one way strips with reasonable safety and repeatability. It is just a matter of being shown the specific disciplines and techniqes applicable to such ops and getting a little dual practice.

 

 

[flie43]

A chart I found earlier off this forum.

 

Terry

 

J430 TO dist chart estimator.pdf

 

J430 TO dist chart estimator.pdf

 

J430 TO dist chart estimator.pdf

[flie43]

I am not sure, but do not think it is a POH document

 

Terry

 

 

[Guest Andys@coffs]

No it isnt a J document rather was done by a group in South Africa that firmly believed J was negligent in not providing this type of info in their POH. So not formal, but I dont see any reason to ignore it. If it says you wont make it for your location altitude, winds and DA then to me youd be a fool to ignore. I have a loose leaf copy of the diagram in my POH.

 

Andy