Fuel Flow Meter Options

[Alan]

What has been peoples experiences with Fuel Flow Meters. Are they worth it? What options are available? Who supplies etc.

 

My Jabiru is LSA so I'm probably not allowed to fit a fuel flow meter anyway. Have to investigate whether this constitutes an Aircraft mod outside the rules.

 

 

[PaulN]

Alan,

 

The CT has only plastic tube "sight glasses" at each wing root (on the end of the fuel tanks) that may be viewed in the cab. Personally I hate them. Never have I been able to read the one above my head and when I do look at the RH one it's usually moving up and down all the time with the movement of the a/c.

 

I have fitted JP Instruments FS-450 and am delighted with it. We do a bit of touring, and frankly I don't know how anyone can confidently travel distances without a fuel readout of some kind.

 

The FS-450 monitors Fuel Used since last refuel, Fuel Remaining, and importantly, Endurance at current fuel burn rate. It also constantly displays current fuel burn rate, which obviously varies with throttle setting. In fact, I often find myself setting the cruise throttle at my preferred fuel burn rate rather than IAS.

 

The instrument can be tweeked over time to set it to reflect the exact numbers of actual fuel usage and remaining. Mine is set so that I can tell to the litre how much fuel is on board.

 

Although I haven't done so, it can be interlinked with the GPS to read out leg quanities also.

 

I wouldn't be without it now.

 

Paul

 

 

[Admin]

Paul

 

The Dynon EMS has all the fuel management in it as well. I was playing around with it in Mudgee the other day and now I have a fuel tank No4 gauge showing on it - dam thing is always empty though - darn computers ;)

 

 

[Yenn]

Do these instruments show actual fuel in the tank or do they deduct fuel as used from what the tank should hold. If they don't show actual tank fuel they will show fuel remaining when you could be out of fuel due to a leak. It does happen occasionally!

 

 

[Admin]

Do these instruments show actual fuel in the tank or do they deduct fuel as used from what the tank should hold. If they don't show actual tank fuel they will show fuel remaining when you could be out of fuel due to a leak. It does happen occasionally!

Ian

It happened to me coming back from Port on Monday and at 7,000ft over very dense tiger country - I ended up using over 35 litres an hour not to mention the potential of an in-flight fire there as well!

 

 

[Guest brentc]

On one occasion I would have run out of fuel if I had a fuel-flow meter fitted. I had a 'leak' as you put it, out my fuel vent. Had I trusted the fuel flow I would have definitely had an engine out.

 

Ian and others, there is a new software version for the Dynon that gives you more info and a HSI plus instant wind figures.

 

eg. Wind 230/15knots and it's all automatic! (if hooked up to your gps)

 

It also displays a digital VOR and lots of other good stuff apparently.

 

 

[PaulN]

Do these instruments show actual fuel in the tank or do they deduct fuel as used from what the tank should hold. If they don't show actual tank fuel they will show fuel remaining when you could be out of fuel due to a leak. It does happen occasionally!

Quite right Ian. If you do experience a fuel leak between the tank and the transducer (flow sensor) it won't register. However, any leak issue that appears beyond the transducer (as in Ian's case) will register as an unexpected high burn rate. So I guess it's in the interest of the owner to install the sensor as close to the tank as possible.

 

For me, it's still a much better option than the inaccuracy of the sight glass. I speak only from my own experience here but the CT sight glass is fitted in such a way that it can't read any fuel in the tank below about 10 litres. Added to that, with its dual feed system (no left or right options, just both simultaneously) it's not unusual for one wing tank to drain sooner than the other, so knowing how much fuel is remaining is pure guess work without the FS-450 (or similar).

 

I read in a US publication somewhere that "aircraft fuel gauges are notoriously inaccurate. In fact the FAA requires only that they read accurately when displaying empty". Hmmm :confused:.

 

Paul

 

 

[Dieselten]

I've had the Mizer fuel-flow meter on the microlight for several years and it has been a very good unit. Needs to be cailbrated for the fuel you are using, but once set it is quite reliable.

 

Shows quantity remaining, total used for trip, total used since last reset, has a low-level alarm threshhold that can be customised by the user and shows flow as well. Can be set for US gallons, Imperial gallons or Litres but not pounds or Kg.

 

Is approved for 95-32 aircraft but the installation must be done/signed off by a Level 2.

 

 

[eastmeg2]

We also have a Fuel-Mizer flow meter on an Edge-X 582 trike and have found that it always indicates about 10% greater fuel flow than reality. This is probably a good thing as the low fuel alarm goes off earlier and gives you more warning. Other than that it's been a great gadget to have on board.

 

We've also recently taken delivery of an XT-912 which has a fuel flow meter built into the glass dash, though it does not appear to be nearly as accurate as the Fuel Mizer. I've read a report from another XT-912 Cruze pilot that a reading of 5.5 L/hr is really 9 L/hr and in my XT-912 with the Streak-III wing I get 6.5 L/hr reading is really 11L/hr.

 

I've already mentioned to the co-owner that I would not go planning any flights to East Timor based on the XT's flow meter readings.

 

Rgds,

 

Glen

 

 

[Yenn]

Seems to me that there are a lot of high tech gauges out there that can't compete for accuracy with a piece of cork and a bicycle spoke.

 

 

[Mc Guyver]

We also have a Fuel-Mizer flow meter on an Edge-X 582 trike and have found that it always indicates about 10% greater fuel flow than reality. This is probably a good thing as the low fuel alarm goes off earlier and gives you more warning. Other than that it's been a great gadget to have on board.We've also recently taken delivery of an XT-912 which has a fuel flow meter built into the glass dash, though it does not appear to be nearly as accurate as the Fuel Mizer. I've read a report from another XT-912 Cruze pilot that a reading of 5.5 L/hr is really 9 L/hr and in my XT-912 with the Streak-III wing I get 6.5 L/hr reading is really 11L/hr.

I've already mentioned to the co-owner that I would not go planning any flights to East Timor based on the XT's flow meter readings.

 

Rgds,

 

Glen

Hi Glen,

 

I have the same problem on my XT912

 

I posted the problem on the microlighters.co.za egroup and the reply was : check that the jet on the inlet side of the fuel flow meter is all the way home.

 

To do this disconect the inlet pipe to the meter and use the back of a drill bit to press the jet in.

 

I tried this today, did not feel any movement in the jet,but it could have moved fractionally.

 

Will try checking accumulated fuel used tomorrow or Saturday to see if there is an improvement:blush:

 

 

[vk3auu]

I believe in the KISS principle. Use a dip stick. After you have flown cross country for a few hours you should know how much fuel your engine will use at various revs.

 

Incidentally, don't fall into the trap that Jabiru did of tuning the carby to run very lean to save a bit of fuel. Nasty things can happen, particularly to air cooled engines when treated that way. Better to run a little cooler with the mixture a bit richer, it is cheaper in the long run.

 

 

[Guest Jacc]

Hello Glen

 

I have a Fuel Mizer fitted to my Edge Outback. It works some of the time but freezes quite a bit. So much so that I do not turn it on very much now. It's a shame because I really would like to use it. I used to run it on an aircraft called an Aerochute, which is basically a 2 seat trike frame with a 503 Rotax motor all dangling from a parachute. Works very well but is slow and thirsty. The fuel mizer worked great on that setup. Accurate to within a litre.

 

I have checked the turbine and it spins freely but maybe the laser light is dirty or something. I notice in one of the replies to your post someone mentioned a "jet" on the inlet pipe to the meter, I don't recall any jet on mine. I will have to have another look. My trike is hangared about a 2.5 hour drive from where I live so I cannot nip outside to check things. Oh well!!

 

Have you heard of anything else that can cause a problem with the meter. It works OK for maybe 10 mins or so, then does not show any flow at all for quite a while then, maybe will read a flow of 2 or 3 (even though I know it is using much more) then will stop again etc.

 

Regards

 

John

 

 

[eastmeg2]

Hi John,

 

From your other post in the "Just Landed" section I'd say we met at the Wang trike gathering at the end of April, I was the one handing over my trike to it's new owner from Tassie. That's a great setup you have with your trike in the caravan.

 

The mention of the jet on the inlet side of the measurement unit was refering to the fuel flow meter on the XT, not the Mizer we have on our Edge X, so I'm not sure if that advice would apply to the fuel mizer or not.

 

It's also nearly 3 hours drive for me to get to our trikes as well, so I have not had the chance to take Mc Guyvers advice yet on the XT.

 

The problem you're having certainly does sound like a problem with your measurement unit though. I sometimes wonder if the units being used are meant for much bigger & thirstier machines, ie, need a greater flow to keep the impellor turning properly.

 

Rgds,

 

Glen

 

 

[Guest Jacc]

Hello Glen,

 

Yes I remember you now. How are you going. Did you get any flying in over the Queen's birthday weekend in that 912?

 

A group of us went away (not trikes, but Aerochute's) and had a great flying weekend. The SMC were holding a fly-in at West Sale airstrip that weekend but I had already promised I would take the trike away with the Aerochute boys, plus as I hangar at Benalla now I would have had to drive to Benalla, then to West Sale. It was just too far.

 

About the Mizer. I used it in the Aerochute which ran a 503, and when I first put it in the trike it worked OK. Something's screwed up somewhere. It's no big deal but it would be handy to have it working.

 

OK Glen hope to catch up with you down the track mate. Safe flying and enjoy that 912

 

Cheers

 

John

 

 

[eastmeg2]

Hi John,

 

We did manage to get in a few hours flying in the 912 on the Sunday 10th June. Popped over to a friends place 20Nm east of us, then North past Neriga (On Nowra-Braidwood Rd) to overfly the Endrich Falls. They were in full flood flow and unfortunately the camera batteries couldn't handle the cold or went flat so we didn't get any shots of it. From there we flew west a bit to check for our mate that the Oallen Ford was not flooded and then followed the High Tension powerlines 25Nm SW back to base.

 

There was some mild bumps on the way back which I guess would have been more unsettling with the older Streak wing but which I've become comfortable with after a few Megafauna's. Like walking on the deck of a yacht I suppose.

 

I'm going through my ASIC application at the moment.

 

Previously when I was only flying 582 trikes I didn't have any real need for an ASIC, but now, having the 912 I can see that I'm going to want to fly this trike much farther a-field and that there will be RPT airports along the way I'll want or need to land at. In the past with the 582/Streak-1 I've flown to Moruya a few times. Now I need an ASIC to land there and with the 912 I can go further down the coast or get in some coastal flying to Albion Park/Wollongong before returning inland to complete the triangle.

 

I'm hoping that some day, given enough time off work, alone or with a group, I'll be able to fly the 912 coastal to Barwon Heads or to Hervey Bay and perhaps further. The 2008 Megafauna to Broken Hill should be a good trip. Maybe I'll have better luck with the weather to be able to fly all the way next year, rather than having to start with a 3 hour tow on the road like I did this year although at least I was able to return in the 912.

 

Maybe next years Wang Trike Gathering will provide some better weather and I'll be able to fly there and back 200Nm each way. See you there either way.

 

Cheers,

 

Glen