How do you check the fuel on preflight

[DontCallMeShirley]

How does everyone visually check their fuel on preflight? I've been noticing the gauges have been slightly erratic, with them bouncing around maybe +/- 1/6th of a tank. The checklist calls for you to visually look in, but normally it is too dark to really see anything but a slight shine of liquid (unless it is topped off). The school also doesn't want students jamming sticks down in the tanks as well.

 

So are there any other methods that can give you a good indication of if you are at say 10 gallons on the main? (R22)

[pilot#476398]

It doesn't help you, but my school had dip sticks. I've seen guys tap the side of the tanks, but I was never any good at that. You could use a flashlight to look inside, or possibly ask the fuel guy how much gas he put in last time, then check the hobbs sheet to see what the last guy flew, to get an idea?

[Guest pokey]

The school also doesn't want students jamming sticks down in the tanks as well.

 

So are there any other methods that can give you a good indication of if you are at say 10 gallons on the main? (R22)

 

i worked part time for an airplane flight school early in my A&P career,,,, you don't know how many hours i spent "fishing" out those damn dipsticks ! Altho they are the best way to tell how much fuel you have, i do not recomend them for flight schools for that reason, i know,, then use a longer one,, seen plenty of long ones in there too. Gages are unreliable and never trust them ! Best thing to do is "sweat it out" get to your destination and then realize that you made it with 6 ounces to spare====NOT !

 

the only sure thing you can tell about a fuel tank, is that it is empty. If it doubt, put more in. 10 gallons won't get you very far anyhow.---well maybe to the crash site

[avbug]

Fuel gauges are supposed to tell you when the tank is empty but don't rely on that. They also won't tell you about fuel starvation with low fuel while maneuvering.

 

Aside from flying, I turn wrenches, and have done all my teenage and adult life. I work on fixed wing, and recently had an aircraft that experienced two fuel gauge malfunctions at the same time; one gauge wouldn't go below 1/2 tank because of a mechanical failure in the gauge. The other gauge stayed on full all the time because of an electrical issue between the indicator and the fuel tank sending unit. In that aircraft, the gauges are used more for balancing the fuel load between the wings, and it uses a simple transfer method of flying uncoordinated or flying with one wing low, to transfer fuel. Imbalance is common, and with 300 gallons of fuel, that's a considerable potential imbalance. Aside from that, the gauges should be reading correctly, and are required legally to read zero when the aircraft is out of useable fuel. Those gauges did neither. One of them could be fixed by replacing the gauge, but the other required additional troubleshooting and work.

 

I flew a small fixed wing Cessna 150 with extended range tanks into a grass strip one day, as a teen. It was part of an ag operation, and rabbit holes and small objects on the strip were common. The standard fare was to fly a low pass down the runway, pull up at the end over a tall stand of pecan trees, do a quick turn, and land the opposite direction. I reached the end, pitched up, and the engine promptly quit. It had a known quantity of fuel, but the larger tanks means it was spread out farther (not as deep in the tank), and at a higher pitch attitude, unported the fuel line, resulting in starvation to the engine. Even with fuel aboard, the engine can quit. I've seen it happen by running a tank dry and being unable to switch, or even systems that caused fuel to auto transfer under normal conditions to a tank which became unavailable.

 

I once checked two different pilots out in a Cessna 210; they were flying for a company that had fixed wing and helicopters, and were the run-around guys that took parts and mechanics to the various aircraft. I made a point of showing them the fuel tanks, which were extended range tanks and had a tall filler neck. I pointed out that because of the design, a visual inspection of the fuel showing fuel at the bottom of the filler neck (full in a standard tank) would be 16 gallons short in each tank...it looked full, but wasn't. If they were used to flying a Standard 210 and checked the fuel, they'd think they had two hours more fuel on board than they really had.

 

BOTH individuals ended up running themselves out of fuel and making off field landings. One of them did it twice. Not the sharpest crayons in the box, apparently, but a reminder to all that caution is the better part of success in aviation. I know an operator who insists that his pilots not fly below 1/2 tanks in his fleet, and he has good reasons for doing so. I don't disagree with his logic.

 

In some light aircraft (R22, for example), fuel fuel and two big guys is going to create issues in certain cases, and we're getting into the season where that becomes a problem.

 

If you're not sure about the fuel state, get sure. If that means adding more fuel to be sure, then do that. You have to start from some known quantity. Don't rely on the gauges. Don't rely on someone telling you that ten gallons are in the tank, or a flight instructor who says "that looks about right."

 

If you're looking in the tank, a sealed beam LED flashlight is a must. Don't get one that's going to cause an explosion, but you can find plenty of safe flashlights that won't present a safety hazard.

 

Rock the aircraft or the tank, you can. Its' easier to see fuel that's sloshing or mobile. If nothing else, wrap on the side of the tank to cause ripples, to make the surface of the fuel easier to see.

 

You'll get a much better feel for gauging fuel in a tank by comparing it to a known quantity. That's best done with a dipstick. So is telling the quantity, but if you can't use a dipstick all the time, then using it sometimes to compare what you think you see to an actual value of what's there will help you develop an eye for knowing the quantity by the depth of the fuel.

 

Remember that in tanks which aren't uniform, which taper, the quantity of fuel isn't just depth; the amount of fuel doesn't decrease at a linear rate as the level goes down. Half-way up the sidewall of the tank doesn't mean you have half-fuel.

 

Tapping on the outside of the tank is most effective if you use a quarter or dime; it takes some practice to get a good feel for where the fuel is, but it should always be combined with other means (visual, dipstick, and gauges) to get the most accurate picture. It's a good idea to see what was in the tank for the last flight, how much was burned, and to to the math. When in doubt, use extra fuel, if at all able. Put it on. Some will say not to put any more fuel on board than what's needed for the flight, because you're carrying around dead weight. I say good; if you can, carry it. It's the most important payload, other than you, that you'll put on board.

[OneCoqui]

Old school pilots just put their finger into the tank... If they can't touch the fuel-they don't fly until it's topped off. Simple! The intended message: Fill your tanks on every pre-flight. RP

[lelebebbel]

If you are flying an R22 with 2 people, you might not be able to top off the tanks every time. Most are already over max gross with 2x180lbs people in the cabin and full fuel.

 

The solution to Don'tCallMeShirleys problem would be to get a little LED torch (with a strap so you don't drop it in the tank). You should have one anyway for your preflight.

Edited May 26, 2013 by lelebebbel

[pilot#476398]

 

i worked part time for an airplane flight school early in my A&P career,,,, you don't know how many hours i spent "fishing" out those damn dipsticks ! Altho they are the best way to tell how much fuel you have, i do not recomend them for flight schools for that reason, i know,, then use a longer one,, seen plenty of long ones in there too...

 

Ok dude I'll admit dropping the stick into the tank hasn't ever crossed my mind, until now,...thanks!

 

However, after reading your post I went out to my car, took my R22 dipstick out of the trunk, went into the garage, drilled a hole through it, and shoved in a piece of string. Voila, problem solved!

[pilot#476398]

Old school pilots just put their finger into the tank... If they can't touch the fuel-they don't fly until it's topped off. Simple! The intended message: Fill your tanks on every pre-flight. RP

 

I've rented an R22 from three different schools, so far, that won't let you top both tanks off for a solo flight unless its well over an hour, because you'll ending up leaving too much gas in there for the next CFI and his student. We're supposed to bring it back with no more than 12 gallons. Such is the world of R22s!

[Eric Hunt]

We made our dipsticks longer than the tank by 7 or 8 inches, and drilled a steel rod through the top end so when the stick is correctly in the tank, the rod is resting on the lip of the tank. The rod would stop the dipstick going into the tank, too, even if it was short enough to get in.

 

We then calibrated it by starting with an empty tank and putting in measured amounts of fuel, marking the rod, and going all the way up to the top. Then turned it around and marked the other side for the aux tank. Fitted under the seat, worked a charm.

 

Dipsticks don't work on a B206 as the filler cap is on the side, and especially not with a range extender.

Edited May 26, 2013 by Eric Hunt

[helonorth]

It's the most important payload, other than you, that you'll put on board.

Neither you, nor the fuel, are considered payload. And you didn't answer the guys question. Nice war stories, though. I particularly enjoyed the "when I was a boy in the 150 ag operation..."

 

If you can't verify by looking in the tank, they won't let you stick it and you can't top it off, you're pretty much at the mercy of the gauge. If they were ever to let you use a stick, it's pretty handy to make it long enough so that it's impossible to fall into the tank.

[Brentd2183]

At my old school we created a fuel stick that worked off the tank sump drains. It was a length of rubber tubing that was attached to a piece of quarter round wood, at the end of the tubing was a chamfered piece of brake line that stuck out an additional inch from the tubing attached to the stick. Hold the bottom of the stick to the bottom of the tank on the outside of the aircraft, insert the metal end into the tank drain and push it, the fuel level rises up and onto the stick which had been marked. We had one stick for the single tank ships and one for the dual tanks. Once done, put your finger on the top end of the tubing, flip it over and let the air bubbles goto the tanks side, pull out and dump the fuel in the tubing into the waste fuel container, works great.

[avbug]

Neither you, nor the fuel, are considered payload. And you didn't answer the guys question. Nice war stories, though. I particularly enjoyed the "when I was a boy in the 150 ag operation..."

 

 

When you can carry two people and not even full fuel, everything is payload. Call it what you will, but it's all payload. No room for baggage, no extras, no additional weight, and can't fill the tanks....you've got basic empty weight, and you've got everything else. Dividing up what makes up the everything else amounts to payload, and the specific way it's defined really depends on the aircraft.

 

No war stories, but relevant examples. I couldn't really give a damn if you like them, however.

 

My employer presently has a policy of never less than half tanks, save for operational necessity. Reaching 1/4 tank in any tank requires a written report to the Chief Pilot.

 

It's a good policy.

[helonorth]

I found your "there I was" stories both relevant and interesting, as always. I can also understand your indifference to my enjoyment of them, as I have made no secret of my assessment of you as an arrogant twit. I do hope, for the enviroment's sake, that you do not run your fuel below a quarter tank ("save for operational necessity"), as your written report would most likely devour an entire section of forest in paper due to your detailed explanation. I would imagine you are busy not-networking to find another job as it's apparent that whatever po-dunk operation you work for has a history of mismanaging fuel in their aircraft with some unfortunate consequences. Good luck.

[Wally]

Better pilots than I have exhausted their fuel in flight.

 

And I look in the tank, however possible- no matches, open flames or other idiocy- but I am looking or otherwise assuring myself that the gauge indicates appropriately. It's a regulatory requirement.

Don't want me jamming a pine branch or length of rope into your aircraft fuel tank, Mr/Mrs/Ms/Miss Operator, you had better have a reliable maintenance record of issues and a maintenance program that calibrates indicated with known quantities... If an operator isn't up to snuff on that small count, big stuff is probably too much also. I ain't flying trash.

Final word- I look. If it don't look right, there's a problem. Approximate is good enough, that's one reason you keep a reserve.

 

I plan to add whatever fuel I need to assure a comfortable margin, and either adjust load or plan a fuel stop. It's easier to de-fuel an aircraft on the ramp than bring fuel to it in a field.

 

I plan maximum endurance and land at a comfortable reserve or when I have reason to suspect that I might burn into that comfortable reserve. Hopefully, there is a reliable low fuel indicator of some sort...

 

Never! Ever! push fuel. Stretching a tank is even stupider than pushing weather or impromptu aerobatics (which is pretty stupid). Assure yourself in whatever way possible that you have enough and accept that you will be wrong at some point. Be wrong with gas on board.

Edited May 27, 2013 by Wally

[avbug]

I found your "there I was" stories both relevant and interesting, as always.

 

 

Whatever. Once again you spend your time in the thread picking away at other's posts, with nothing useful to contribute. Shocking.

[eagle5]

How does everyone visually check their fuel on preflight? I've been noticing the gauges have been slightly erratic, with them bouncing around maybe +/- 1/6th of a tank. The checklist calls for you to visually look in, but normally it is too dark to really see anything but a slight shine of liquid (unless it is topped off). The school also doesn't want students jamming sticks down in the tanks as well.

 

So are there any other methods that can give you a good indication of if you are at say 10 gallons on the main? (R22)

 

If you'd gone to HeliExpo and participated in the Rotor Safety Challenge you would have gotten this nifty little HAI key chain/led flashlight when you turned in your chips, to help you see into the tank,...although you could just end up dropping your keys into the tank!

 

How does your CFI check the fuel level? Plus, can you legally fly with the fuel gauge bouncing around?

Edited May 27, 2013 by eagle5

[avbug]

Plus, can you legally fly with the fuel gauge bouncing around?

 

 

 

Yes. However, what is legal isn't necessarily safe, and what is safe isn't necessarily legal. Unless both conditions are met, one should not go.

[Guest pokey]

At my old school we created a fuel stick that worked off the tank sump drains. It was a length of rubber tubing that was attached to a piece of quarter round wood, at the end of the tubing was a chamfered piece of brake line that stuck out an additional inch from the tubing attached to the stick. Hold the bottom of the stick to the bottom of the tank on the outside of the aircraft, insert the metal end into the tank drain and push it, the fuel level rises up and onto the stick which had been marked. We had one stick for the single tank ships and one for the dual tanks. Once done, put your finger on the top end of the tubing, flip it over and let the air bubbles goto the tanks side, pull out and dump the fuel in the tubing into the waste fuel container, works great.

 

Nifty idea ! Was the rubber tubing clear? If it was clear tubing, just plug it onto the sump drain, hold it up against side of the tank & the level in the tube will rise to the level in the tank.

[OneCoqui]

If you are flying an R22 with 2 people, you might not be able to top off the tanks every time. Most are already over max gross with 2x180lbs people in the cabin and full fuel.

 

The solution to Don'tCallMeShirleys problem would be to get a little LED torch (with a strap so you don't drop it in the tank). You should have one anyway for your pref

I flew the "Alpha" model of the R22 back in the late 80's... Too limited in my opinion. Nothing less than S-300C or an R44 for this CFI. My mentors (military and civilian) never taught to me to "partially" re-fuel any helicopter. Top them off always! RP

[OneCoqui]

 

I've rented an R22 from three different schools, so far, that won't let you top both tanks off for a solo flight unless its well over an hour, because you'll ending up leaving too much gas in there for the next CFI and his student. We're supposed to bring it back with no more than 12 gallons. Such is the world of R22s!

That is bad JU-JU.... Bad habits will prevail!

[DontCallMeShirley]

If you are flying an R22 with 2 people, you might not be able to top off the tanks every time. Most are already over max gross with 2x180lbs people in the cabin and full fuel.

 

The solution to Don'tCallMeShirleys problem would be to get a little LED torch (with a strap so you don't drop it in the tank). You should have one anyway for your preflight.

 

Does anyone have any recommendations of a LED torch that you like? This sounds like a good first step, but don't want to get one that could be hazardous if dropped in the tank. I think I saw someone mentioned a sealed LED light with the addition of a strap.

 

 

We made our dipsticks longer than the tank by 7 or 8 inches, and drilled a steel rod through the top end so when the stick is correctly in the tank, the rod is resting on the lip of the tank. The rod would stop the dipstick going into the tank, too, even if it was short enough to get in.

 

We then calibrated it by starting with an empty tank and putting in measured amounts of fuel, marking the rod, and going all the way up to the top. Then turned it around and marked the other side for the aux tank. Fitted under the seat, worked a charm.

 

Dipsticks don't work on a B206 as the filler cap is on the side, and especially not with a range extender.

 

Speaking of a 206. I've heard through a friend that his cousin is flying tours out west somewhere and their fuel gauge has been broken for over a year. I'll see if I can ask, but how would one check the fuel on that assuming a flat out broken gauge? Top off every time?

 

If you'd gone to HeliExpo and participated in the Rotor Safety Challenge you would have gotten this nifty little HAI key chain/led flashlight when you turned in your chips, to help you see into the tank,...although you could just end up dropping your keys into the tank!

 

How does your CFI check the fuel level? Plus, can you legally fly with the fuel gauge bouncing around?

The CFI's don't check the fuel level, everything is 100% reliant on the gauge. A lot of the time we do our own fueling so we know that fuel is going in, but unless we top off the Aux tank, or the main, its anyones guess as to how much is in there. As mentioned above, this means our flight time is just an approximate, and our max gross weight is questionable.

 

Usually the the gauge will read fairly accurately, i.e it will increase in proportion to the amount of fuel you are putting in, but only recently did I notice it was bouncing around quite substantially to the point where 30 minutes of fuel was uncertain.

 

Adding a piece of tubing and pointing it straight up on the drain ports might be a viable solution. Not sure if that would just get messy though or be excessively cumbersome.

[Wally]

In the 45 years since I soloed, the times I've been able to top off the aircraft I fly professionally would be in the low single percentages. Full seats, baggage/cargo and full tanks just don't happen often enough to be useful habits. Check for quantity aboard against requirements, load to that condition (the FBO that sells fuel has the metering device routinely calibrated and probably much more reliable than your gauge), respect your reserve, and use the most conservative calculation- timed fuel burn amount, fuel gauge, or religious faith in the low fuel light when it illuminates.

It's reactionary and a particularly personal prejudice of mine that the pilots I've worked with who had the "top off addiction" created extra work for the other pilots who actually planned fuel. Get in the habit, early!, like from ab initio, become proficient planning necessary fuel load, fuel consumption and refueling considerations. Further, the assumption of a particular fuel state as a standard is at the very least counter-productive if not unsafe.

Edited May 27, 2013 by Wally

[pilot#476398]

I flew the "Alpha" model of the R22 back in the late 80's... Too limited in my opinion. Nothing less than S-300C or an R44 for this CFI. My mentors (military and civilian) never taught to me to "partially" re-fuel any helicopter. Top them off always! RP

 

Something tells me you come from a place where no one is taller than 5'9" or heavier than 135lbs?

[Counterrotate]

To answer the original poster's question, use a dip stick. Use one that is at least 6 inches taller than the tank so it absolutely WILL NOT fall in. Whoever said they have spent a good deal of time fishing out dip sticks is dealing with some special people. Keep in mind that your dipstick indication is not giving you an accurate indication of how much fuel is in the tank, but an approximation. Whether visually looking in the tank with a flashlight, checking the gauge, using a dipstick, or tapping on the side of the tank, it's all an approximation. There are some aircraft out there that have some very accurate methods of measuring the quantity of fuel in the tank. Most don't. As has already been stated multiple times by others, the fuel quantity indicators are only required to read accurately when they are at zero. Anything in between zero and full is a guesstimate. Never, ever rely on gauges alone to tell you how much fuel you have. If you are really low, but can't tell exactly how much you have, make sure you put in the known quantity that you need to complete the flight with adequate reserves. Anything extra is just that, extra. If you are flying an R22 and weight is a concern, you need to make an educated guess, it takes some interpolation. Base your educated guess off of known quantity put into the tank when fueling, visual indications when looking in the tank, and then bounce it off what the gauge reads. If it all jives, you are probably good to go, within a fair margin. If you are in a situation where in order to accomplish the flight, you are risking being either over-gross on the front side, or running into your reserves on the backside, you need to come up with another flight plan. Simple as that. There is no excuse for poor flight planning.

[eagle5]

The CFI's don't check the fuel level, everything is 100% reliant on the gauge. A lot of the time we do our own fueling so we know that fuel is going in, but unless we top off the Aux tank, or the main, its anyones guess as to how much is in there. As mentioned above, this means our flight time is just an approximate, and our max gross weight is questionable.

 

Usually the the gauge will read fairly accurately, i.e it will increase in proportion to the amount of fuel you are putting in, but only recently did I notice it was bouncing around quite substantially to the point where 30 minutes of fuel was uncertain.

 

 

Your CFIs rely 100% on the gauge, and the gauge is malfunctioning,...Shirley you must be joking!

 

I don't know if this is possible, but it seems like if manufacturers could put some kind of markings inside the tank (like flourescent tape or something) that we could shine a flashlight on, it would make this whole thing a lot easier?

 

By the way, my advice is to (when your CFI isn't looking) use a dipstick anyway!

 

Edited May 27, 2013 by eagle5