Additional sight gauges
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bob turner
Registered User
Most of the gauges I have seen are clearly calibrated and labeled for three point and level flight.
Steve Pierce
BENEFACTOR
Graham, TX
This is why I loved my FP5L fuel flow/totalizer in my Pacer and last Super Cub and my CGR30P in the present Cub. I drian the fuel from time to time and it is always within 1/2 a gallon of what the instrument is telling me. Peace of mind.
Steve Pierce
BENEFACTOR
Graham, TX
I never had any problem reading my sight tubes with Atlee’s tanks. I remember the day Mike and I marked them 5 gallons at a time in 3-point and lifted to level flight. Lifting the tail got very difficult as those tanks got over half full. A good lesson in fuel CG! My Back Country’s tanks have the sight tubes angled incorrectly. The indications at 3-point and level flight are wildly different. They’re fine in flight, though. A dip stick is a better tool on the ground.
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mvivion
FOUNDER
Bozeman,MT
Bingo! After a crankshaft failure resulted in the need for a replacement airplane, I was asked what specific equipment I needed in the replacement. First on that list was a fuel flow and totalizer computer. They weigh practically nothing, but are pure magic.
MTV
frequent_flyer
Registered User
Arizona, USA
They are only as good as the K factor calibration and the consistency of K factor with varying fuel flows. Consistency with flow rate may vary between sensor manufacturers but, after putting nearly 1,600 gallons through mine and logging every drop, I still need to tweak my K factor again to try to eliminate a 2% error.
I would not get rid of the sight gauges and rely only on a flow meter. Too many failures of "cube" sensors have been reported.
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A dip stick and a watch continue to be my most trusted fuel gauge. I have fuel monitors in both planes and both serve to validate what the dip stick established.
I do know of a fuel exhaustion accident where a 185 pilot relied on a totalizer, wasn’t aware of a leak upstream of his transducer, and wasn’t cross-checking his fuel quantity gauges along the way. When it comes to fuel, I don’t rely on a single instrument.
I do know of a fuel exhaustion accident where a 185 pilot relied on a totalizer, wasn’t aware of a leak upstream of his transducer, and wasn’t cross-checking his fuel quantity gauges along the way. When it comes to fuel, I don’t rely on a single instrument.
Steve Pierce
BENEFACTOR
Graham, TX
The totalizer is never a substitute for an actual gauge but it sure does help. I do a lot of short hops and I find the totalizer very handy.
I left my gas cap off and headed off on a trip with my wife. We were talking etc and I wasn't doing my usual cross checking of site gauges like I do when I am by myself flying long distances. Got exciting when the engine quit and I had to put it down. All worked out but another case of "use all the tools in the box".
I left my gas cap off and headed off on a trip with my wife. We were talking etc and I wasn't doing my usual cross checking of site gauges like I do when I am by myself flying long distances. Got exciting when the engine quit and I had to put it down. All worked out but another case of "use all the tools in the box".
frequent_flyer
Registered User
Arizona, USA
The acceptable error in a fuel totalizer may depend on how often it is reset to a known fuel quantity.
Steve seemed happy that his error was about 0.5 gallons per tank. Don't know his total fuel capacity but guessing at 40 gallons that's a 2.5% error. That's not a problem if each refuel is to full and the totalizer is reset each time. I run my totalizer over multiple partial fills which have no reference to reset the totalizer.
I wish my tanks had an accurate partial fill reference that I could see while fueling (like the tabs on a PA-28). It may be possible to improvise one but the FX-3 filler necks are small and mostly filled by a standard 100LL nozzle.
Steve seemed happy that his error was about 0.5 gallons per tank. Don't know his total fuel capacity but guessing at 40 gallons that's a 2.5% error. That's not a problem if each refuel is to full and the totalizer is reset each time. I run my totalizer over multiple partial fills which have no reference to reset the totalizer.
I wish my tanks had an accurate partial fill reference that I could see while fueling (like the tabs on a PA-28). It may be possible to improvise one but the FX-3 filler necks are small and mostly filled by a standard 100LL nozzle.
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mvivion
FOUNDER
Bozeman,MT
First, I never suggested getting rid of fuel gauges, and I never would suggest that. There are obvious situations, as noted by others, where one needs to pay attention to ALL fuel indicators. That said, particularly with very large tanks, like the Atlee 60 gallon tanks, and the big Cessna 84 gallon tanks, a fuel computer is an invaluable tool, which, combined with accurate metering of fuel INTO the tank, permits one to operate at relatively light weights, or carry larger loads internally.
I put ~ 3500 plus hours on a C-185, carrying loads on nearly every flight…..and only rarely topping those big tanks. On the rare occasion when I needed max fuel, I was always amazed at the accuracy of the totalizer….there were instances where I hadn’t topped off for fifty plus hours, and a fill up came out within one to two gallons. I’ll take that every day.
On that plane, I never reset the K Factor from factory settings. On my 170 with O-360, it took two runs at tweaking the K Factor to get it below 1%. Three other 185s, three Huskys and two Cubs with Atlee tanks, and my current 175 all ran within 1 to 2 % accurate. Two percent of 60 gallons comes out to just over a gallon.
If you’re cutting fuel that close, wear a helmet. 8) :roll:
But, yes, the totalizer is simply one of the tools, use them all. That said, every plane I’ve owned for forty years plus has had a fuel computer installed.
MTV
skywagon8a
MEMBER
SE Mass MA6
A thought. Install a T at the rear fuel outlet. Get a longer piece of that plastic tubing and connect the lower end at the new T. Cap off the current lower gage fitting in the tank. This will give you a bigger picture of what is inside the tank.My Back Country’s tanks have the sight tubes angled incorrectly. The indications at 3-point and level flight are wildly different. They’re fine in flight, though. A dip stick is a better tool on the ground.
bob turner
Registered User
On a slightly different subject - a buddy has a Taylorcraft L2, and while I won’t be signing his annual, I have been insisting that he get a gauge like the above. He wants a formed glass tube, to preserve the original look.
If that Back Country deal is adjustable in length, and available, that might be what he needs.
I am only involved to the extent that I covered the thing, and I have a signed document that says it will not be Olive drab or otherwise camouflaged while I am still able to fly.
If that Back Country deal is adjustable in length, and available, that might be what he needs.
I am only involved to the extent that I covered the thing, and I have a signed document that says it will not be Olive drab or otherwise camouflaged while I am still able to fly.
They are awesome and typically accurate within about 1/10 gallon on my 75g Skywagon tanks. However, I never depart remote area strips without dipping the tanks.
skywagon8a
MEMBER
SE Mass MA6
Any length you wish.
Steve Pierce
BENEFACTOR
Graham, TX
I have stock 18 gallon tanks and I almost never fill them up unless I am going on a trip. I fly with 8-15 gallons normally and every now and again when I come back and my tanks are real low I will drain them and check. It is never off more than 1/2 a gallon out of the whole system. I refuel out of my fuel tank mounted on a trailer with a mechanical gauge.
Any length you wish.
Atlee’s have 90° bends and restrictors in the ends. Like airplane parts should.
I do a lot of long distance trips up here and it is sure nice to know how long the stove will run when you are getting into some weather and headwinds on the way home. It allows you to make better decisions knowing exactly what you have on fuel. Yes use a calibrated dip stick for the input each fill up.
When the cube fails you will see numbers that do not make sense on the fuel totalizer. I never had a problem knowing that is is slowing down.
If you spray it with a lubricant inside it will work again for a day or 2 then you know for sure you have a bad cube.
When the cube fails you will see numbers that do not make sense on the fuel totalizer. I never had a problem knowing that is is slowing down.
If you spray it with a lubricant inside it will work again for a day or 2 then you know for sure you have a bad cube.
I usually always leave with full tanks because I always try to fill them when I am done for the day. If I am going to a STOL comp I try to cough the right tank on the trip and arrive with only 5-10 in the left. Drain the left tank with gascolator and put back only 5 gal for the event. The biggest problem I have with fuel is I have other pilots that fly the plane all Dam ATP pilots. It seems they can't fly more than 30 min before they have to start playing with the fuel valve!! Even a 1 hour flight they will have used fuel from both tanks!! Not a huge deal but now I get to fuel both tanks instead of just one. It just makes the grumpy old man in me start to bitch and moan. It is hell to have 1st world problems.
DENNY
DENNY
mvivion
FOUNDER
Bozeman,MT
In a Cub with stock type fuel selector, I ALWAYS take off on left tank, then when at altitude, switch to right tank for ~ 15 minutes or so to verify fuel will flow from both tanks. I generally run right tank down first so I have left for landing approach.
Depending on your airplanes mods, none of that may matter. Just be certain you fully understand the fuel system on the airplane you’re flying.
MTV
Depending on your airplanes mods, none of that may matter. Just be certain you fully understand the fuel system on the airplane you’re flying.
MTV
skywagon8a
MEMBER
SE Mass MA6
CubCruiser
SPONSOR
Ormond Beach, Florida
Steve Pierce
BENEFACTOR
Graham, TX
Yea but somewhere in there ya have to pee.
frequent_flyer
Registered User
Arizona, USA
What is the purpose of the red lines? They will seldom be parallel to the fuel maniscus and when they are you will probably have more to think about than fuel quantity.
