jabiru down brisbane

[turboplanner]

Well, don't fly any aircraft with bag tanks, then; (and yes, quite a lot of Cessna have them, as well as Beech 33, 35, 55, 58, or a Lancair 4 - or, in fact, about half the GA fleet.) The only practical way with any of these is to start with full tanks. The reality is that fuel contents gauging is a significant problem in a great many aircraft.

...but not necessarily in the market leaders most of us fly.

 

 

[Oscar]

Would I be considered a Jab Basher if I suggested that is the result of piss poor design or lack of proper testing ??.....

So, two reported/suspected cases out of many hundreds flying. Well less than 1% of all Jabs with wing tanks. The pernicious intent of the comment is obvious.

 

 

[Russ]

Did some flying on the weekend in the first kit built Jab completed in Australia (now VH-JBU) recently rebuilt and now with a 2200 replacing the original 1600. Did notice a tendency to turn to the RIGHT even with the ball well centrered. Owner said it used to go left prior to rebuild. I suggested he drop the right hand flap down very slightly. Other than that it seem to perform well..........Maj....

I know of a couple similar, fix was a washer under one engine mount to alter thrust line just a poofteenth.

 

 

[Russ]

Query.......220F ( 104 C ) , is that a good CHT at LHR head. At cruise. ( 2200 engine)

 

 

[Dafydd Llewellyn]

Query.......220F ( 104 C ) , is that a good CHT at LHR head. At cruise. ( 2200 engine)

If you can believe the instrument, cause for checking that it's over-rich. If both confirmed OK, cause for champagne . . .

However, I'd be very wary of an instrument that gave that kind of reading at cruise. Even more suspicious at full throttle.

 

 

[Russ]

Was about to switch the pewter off......read your reply,

 

J160C, factory instruments.

 

Temp is cruise temp, at 2800 revs, goes slightly higher at full power, recently fitted latest jab needle kit. ( richer, not much ) burns 15LPH.

 

But........added a bigger lower cowl lip, seems to be the answer.??

 

 

[turboplanner]

So, two reported/suspected cases out of many hundreds flying. Well less than 1% of all Jabs with wing tanks. The pernicious intent of the comment is obvious.

Two reports in a single thread Oscar doesn't make anything other than jelly.

 

 

[Oscar]

Absolutely correct, Turbs - a wobbly concoction with artificial colouring and flavoring, at best..

 

 

[gandalph]

Would I be considered a Jab Basher if I suggested that is the result of piss poor design or lack of proper testing ??.....

Hell no Maj, Your credentials in that field at least are already well known.

 

As if you needed to ask..... Really!

 

 

[Teckair]

Two reports in a single thread Oscar doesn't make anything other than jelly.

This is 2 prangs we are talking about.

 

 

[Dafydd Llewellyn]

No, remember that the report on the Brisbane prang that was the original subject of this thread, has not yet been issued - unless I've missed something. This question of fuel-still-in-tank-due-to-flying-crabwise is still conjecture. Teckair mentioned another, but did not identify it or give a link to the report that reached that conclusion. I asked whether anybody had knowledge of a verification of this rumour, and this whole debate took off without anybody answering that question.

 

 

[gandalph]

No, remember that the report on the Brisbane prang that was the original subject of this thread, has not yet been issued - unless I've missed something. This question of fuel-still-in-tank-due-to-flying-crabwise is still conjecture. Treckair mentioned another, but did not identify it or give a link to the report that reached that conclusion. I asked whether anybody had knowledge of a verification of this rumour, and this whole debate took off without anybody answering that question.

As threads are wont to do here. Not sure if many of our members are property developers but there sure are a lot of speculators here.

 

 

[frank marriott]

Fuel in the tanks was only stated by the operator ? butt protecting? Authorising an RAA certificate pilot to take a joy flight with Pax from CTA - I would be surprised if the operator is not in a damage control mode?

 

 

[Teckair]

No, remember that the report on the Brisbane prang that was the original subject of this thread, has not yet been issued - unless I've missed something. This question of fuel-still-in-tank-due-to-flying-crabwise is still conjecture. Teckair mentioned another, but did not identify it or give a link to the report that reached that conclusion. I asked whether anybody had knowledge of a verification of this rumour, and this whole debate took off without anybody answering that question.

I was talking to the pilot today the prang happened yesterday the details are as reported to me by the pilot. I did not get or ask for permission to make the identity of the pilot or owner of the aircraft public but it certainly happened. It has been stated in this thread the Brisbane prang did not run out of fuel and I am sure I remember someone saying one tank was empty. You guys are clutching at straws.

 

 

[Dafydd Llewellyn]

No, I'm not clutching at any straws; I'm not trying to prove anything. I just want real evidence, not hearsay. Let's get to the facts.

 

 

[Teckair]

I have asked for permission to give more details about the most recent crash, hopefully it will be today.

 

 

[turboplanner]

No, I'm not clutching at any straws; I'm not trying to prove anything. I just want real evidence, not hearsay. Let's get to the facts.

What facts do you want?

 

 

[Dafydd Llewellyn]

The real cause of the incident/accident; or failing that, sufficient confirmed information on which to base some analysis. I'm setting up to do some research on a Jabiru engine with some of Ian Bent's modifications - initially, to shake-down the test cell and run-in the motor (which is a "loaner") in the process; later, to run one of Ian Bent's fully-modified engines through the JAR 22H endurance test requirement. So I'm looking for things that will allow me to design useful research tests that can be done in this facility. I'm trying to get a real understanding of what to look for and how to look for it, in other words.

 

The first bit of research is to get the engine baffling right, for the "downflow" style of cooling system that is conventional on horizontally-opposed air-cooled engines.

 

The second bit is to see what I can discover about the mixture distribution - and depending on what that shows, what can be done to improve it. That comes in two parts - the effect of the engine itself; and the effect of the means of air supply to the carburettor.

 

Obviously, the scope of this does not extend to the aircraft fuel system; but I'm interested to know whether this Brisbane accident was an engine problem or a fuel system or pilot fuel management problem. So far that's not unequivocally clear.

 

 

[01rmb]

It was nothing to do with the engine. It was a fuel starvation issue - with an amount of fuel left in a wing tank when the aircraft is flown with that wing low.

 

Like Nat King Cole said - "Straighten up and fly right".

 

 

[geoffreywh]

Scary! at least 15 litres+ left ( 45 minute reserve ) and not knowing you are not gonna be able to use it. I'm so glad it wasn't me Well done the PIC.................right?

 

 

[dazza 38]

Scary! at least 15 litres+ left ( 45 minute reserve ) and not knowing you are not gonna be able to use it. I'm so glad it wasn't me Well done the PIC.................right?

So I take it that the left tank had it's fuel selector selected in the off position ? If not, and the selector was selected open and feeding fuel to the engine, why didn't the remaining 15 litres in the left tank feed the engine?

Ps- I don't know the Jabs fuel system. I only flew the LSA 55 and it only had one tank behind the seats.

 

 

[Dafydd Llewellyn]

Looking at the POH from the Jabiru website, the J 170D has an "all on" fuel system, using two long wing tanks plus a collector tank. The POH gives the usable fuel as 135 litres, and shows the unusable fuel as 5 litres.

 

The normal method of determining the unusable fuel is given in FAA AC 23.16A ; attached is an extract. These tests are normally used in my experience, regardless of the aircraft category. Therefore, it would follow that the normal expectation of a certificating authority is that uncoordinated flight will not normally be sustained for more than 30 seconds at a time.

 

 

 

[Jabiru Phil]

There are no fuel selecters in a j230 if someone can also repeat this for dazza asI am on his ignore list

If they ran out of fuel and there was some in the tank after crash Geoffrey is right on they did not cary enough fuel for the flight

 

nothing is wrong with the jabiru fuel system this would be a rare event

Kit built 230 had the two wing tank valves.

 

Earlier models had no header tank either.

 

 

[Guest Andys@coffs]

There are no fuel selecters in a j230 if someone can also repeat this for dazza asI am on his ignore list

If they ran out of fuel and there was some in the tank after crash Geoffrey is right on they did not cary enough fuel for the flight

 

nothing is wrong with the jabiru fuel system this would be a rare event

So that statement is almost correct.....There are no fuel selectors in current J230's....older ones like mine have a main tap on the center console and one on each pillar just below the fuel sight glasses.... If I want to fly on one wing or the other only I can do so, however as others have said...fly co-ordinated and there really isn't an issue....fly uncoordinated and it wont matter how many taps you have because when the unbalanced flight is making the last 15litres rest against the outboard tank bulkhead well away from the pickup point then you be in trouble......

 

If you are truly flying with only 15lt's remaining then unco-ordinated or not that represents a failure all of its own IMHO. 15Lts remaining or 0Lts its all the same to me especially for a local flight..... That saying. Useless things in aviation, runway behind and fuel on the ground...... I could accept 15lts remaining on a long flight where that was the planned fuel remaining and because it was a long flight fuel management was something that was done throughout the flight....on a local flight....not so much IMHO

 

Andy

 

 

[Old Koreelah]

Are Jabiru wing tanks of constant chord, or do they taper? In level flight the wing will slope down a little at the back, so if the aft edge of the tank tapers up towards the wingtip, it would take significant out-of-balance flight to prevent fuel from reaching the outlet.