Auxiliary fuel tank (temporary installation)

[awarren.darwin]

Hello

 

Does anyone have any experience of installing a temporary auxiliary fuel tank to a Jabiru? I have a Jab J400 with a capacity of around 125 litres (wet wing). I'd like to extend the capacity by 20 litres or so for a journey over water. I can see how I can secure a jerry can in the cockpit. However, I'm not sure how best to safely plumb in a feed from the jerry can. Anyone have any ideas?

 

Thanks

 

Alan

 

 

[kaz3g]

Yes...Don't!

 

At the very least buy yourself a portable fuel tank for a boat properly fitted with a vent-able cap. Land the aeroplane and top up the tanks on the ground. If the weather is hot, vent the tank away from the aircraft before opening. Your bladder will have you down somewhere before you run out of fuel, anyway.

 

If you want something you can plumb into the system, then perhaps a Little Buddy flexible tank which comes at a price but is complete with electric pump and fittings?

 

Kaz

 

 

[Guest Andys@coffs]

HelloDoes anyone have any experience of installing a temporary auxiliary fuel tank to a Jabiru? I have a Jab J400 with a capacity of around 125 litres (wet wing). I'd like to extend the capacity by 20 litres or so for a journey over water. I can see how I can secure a jerry can in the cockpit. However, I'm not sure how best to safely plumb in a feed from the jerry can. Anyone have any ideas?

Thanks

 

Alan

so your looking for 5+hrs of over water operations? not under RAAus I take it cause our limitations don't let you get 10 mins from shore let alone hrs (Duh...stupid Q...its a J400 so not RAAus)

 

From where to where?

 

Andy

 

 

[planesmaker]

You could reduce cruise speed to 100 kts and reduce fuel consumption to about 17 l/hr giving almost 7.5 hrs which will extend your still air range with no reserves by about 150 nm. Tom

 

Much cheaper alternative and in the end less time is spent too.

 

 

[Alan]

I find that if I go below 20 l/hr in cruise my EGTs rise, the lower the flow the worse it gets. I generally set to a min of 21 l/hr unless turbulence requires a lower airspeed - then closely monitor the EGTs.

 

Alan

 

 

[planesmaker]

I find that if I go below 20 l/hr in cruise my EGTs rise, the lower the flow the worse it gets. I generally set to a min of 21 l/hr unless turbulence requires a lower airspeed - then closely monitor the EGTs.Alan

Mate I would get that fixed before any overwater flight. Check with Jabiru what jets you should have fitted. Sounds like running a bit lean. Tom

 

 

[Russ]

Observed a jab recently that owner plumbed into the line from header tank to engine via a T piece, a short line was installed with a marine quick release fitting attached, he then placed a bladder onto that rear luggage platform, and connected it to that available fitting, gave him an extra 30litres, said it worked a treat . In effect the engine drew from the bladder, that in turn was being kept full by the wing tanks.

 

Remembered this method for an option.

 

 

[Yenn]

When I had a Drifter I put a spare tank on the passenger seat. I had a fuel line from the bottom of this tank, into the fuel tank., this was sealed into the fuel tank lid. The line was sealed at the spare tank lid and I had a vent also sealed into the lid. That meant that the spare tank was used up as the main tank was used and when empty it became the main vent.

 

 

[Ultralights]

if your EGT's come up with throttling back, it means your running lean of peak at open throttle, no problem here. save fuel, engine runs smother and cleaner. This is where you want it for longest range. so if your closing the throttle, less air, mixture is getting richer and EGT is climbing, your are approach Peak EGT from the LEAN side. so throttle back until you get to peak, the add a little throttle and you should be about about 50degF lean of peak, getting the most power for the fuel burn.

 

 

BSFC is the Horsepower per fuel burn, the higher the better. high CHT and ICP (internal combustion pressures) are bad.

 

High EGT temps are a non event, remember PEAK egt is the PEAK, it cannot get any higher no matter the mixture.. it will either cool as you get leaner, or cool as you get richer from peak. and dont forget, the LOCATION of the EGT sensor will have a huge effect on the reading... nothing to worry about with high EGT's its the CHT you have to watch, a CHT runaway with preignition can kill an engine in no time. (minutes or less) EGT is only a measure of the fuel air ratio.

 

at above about 6500ft, running just lean, or peak EGT will be the most fuel efficient and wont hurt the engine. at lower levels, you either want full rich and a cool egt, or lean of peak. just rich of peak means highest cylinder pressures and highest CHT'!

 

 

[dlegg]

if your EGT's come up with throttling back, it means your running lean of peak at open throttle, no problem here. save fuel, engine runs smother and cleaner. This is where you want it for longest range. so if your closing the throttle, less air, mixture is getting richer and EGT is climbing, your are approach Peak EGT from the LEAN side. so throttle back until you get to peak, the add a little throttle and you should be about about 50degF lean of peak, getting the most power for the fuel burn.

 

BSFC is the Horsepower per fuel burn, the higher the better. high CHT and ICP (internal combustion pressures) are bad.

 

High EGT temps are a non event, remember PEAK egt is the PEAK, it cannot get any higher no matter the mixture.. it will either cool as you get leaner, or cool as you get richer from peak. and dont forget, the LOCATION of the EGT sensor will have a huge effect on the reading... nothing to worry about with high EGT's its the CHT you have to watch, a CHT runaway with preignition can kill an engine in no time. (minutes or less) EGT is only a measure of the fuel air ratio.

 

at above about 6500ft, running just lean, or peak EGT will be the most fuel efficient and wont hurt the engine. at lower levels, you either want full rich and a cool egt, or lean of peak. just rich of peak means highest cylinder pressures and highest CHT'!

Very informative, thanks, but sure that LOP only applies if you have manual mixture control. Rotax and Jab are at the mercy of bing.

 

 

[kaz3g]

kaz3g, Alan the poster said that he wants to do an over water fright (flight) so he will struggle to fill up on the ground!!!!

Best he stays away from the water for that very reason.

 

If Alan's Jabiru is registered VH and he wants to plumb an auxiliary in to his fuel system, then he will likely require an engineering order and any work will have to be done to aviation standards. A "plumbed in jerrycan" is not going to cut it.

 

Kaz

 

 

[Oscar]

Since it's a J400, then it is VH-reg. Turtle-Pak make certified ferry tanks (a bit larger than what is actually wanted, but the smallest is not very heavy) that are certified and quite often used - and you don't have to fill them right up, of course). It's not at all unlikely that buying one of these and getting an EO for fitting it would be cheaper than any alternative that will require testing etc. for an EO to be issued. My nephew did quite a bit of work with Laszlo on developing aircraft installs (even went to Oshkosh with him to demonstrate then over there a few years ago) and found the products and the company to be excellent quality.

 

http://www.turtlepac.com/products/collapsible-aircraft-ferry-tanks.html

 

 

[awarren.darwin]

Hi All

 

There's some interesting information in this forum - thanks for your replies. I'm in the early stages of planning to fly from NZ to Australia via Norfolk Island and Lord Howe Island. The TurtlePac sounds like a viable but expensive option, but even so, I'm still not convinced I want to risk this flight. If I were to go for the TurtlePac option I'd get a LAME to fit it and make it "legal".

 

Cheers - Alan

 

 

[Oscar]

Alan - I'm neither trying to be a smart-arse here nor sell you a Turtle-pak, but if I were thinking of this flight I'd be looking into making it 'legal' all right (and an EO will almost certainly demand LAME installation) - I think you may find that you'd be breaking all sorts of rules (some of them with not insignificant penalties) and almost certainly voiding your insurance cover otherwise. And, if you recall the Pel-Air crash background information that came out, Norfolk Island has a notoriously changeable weather situation, you do NOT want to be without adequate fuel for a diversion - and there aren't many options way out there. If I read my Google Earth properly, you need rather more than 20 litres extra to divert to Lord Howe if Norfolk socks in, or to Australia if Lord Howe exceeds max. crosswind!.