Psychology of fuel management

[Bill Watson]

Question: Do you trust your fuel gages? Why?

I trust mine because I have two systems in my RV; float gauges and a totalizer. Then they are displayed superimposed on top of each other so they can be compared. If they differ, something is inaccurate but otherwise as long as they agree, I trust them.


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[asicer]

Which is not what the FARs say, but it’s a nice OWT that won’t die.

I don’t trust mine either but not because of an OWT about the FARs. Just because they suck.

But then again, FAAs “fix” for it in the certification regs would make the things cost a couple thousand bucks for a problem solved by a free paint stirring stick from Home Depot and a watch.

Do you trust your watch?

 

[idahoflier]

Which is not what the FARs say, but it’s a nice OWT that won’t die.

I don’t trust mine either but not because of an OWT about the FARs. Just because they suck.

But then again, FAAs “fix” for it in the certification regs would make the things cost a couple thousand bucks for a problem solved by a free paint stirring stick from Home Depot and a watch.

Not an OWT. Please see FAR 23.1337. BTW, that FAR isn't why I don't trust them...

 

[woodchucker]

You plan your flight, you know your fuel burn. You hope that winds and other conditions hold as forecast (but you should monitor that and have alternatives ready to go to). But still every flight yields lessons.

My first really long XC from SLC to Denver had a scarcity of airports along the way. My planned fuel stop didn’t have a sole at the airport. No self-serve that I could see. I learned a lesson here: call ahead to verify.

Psychologically speaking, I’m not sure where to go with that. We are human. We make mistakes. We shouldn’t be making mistakes that put us at risk, but we do.

 

[denverpilot]

Not an OWT. Please see FAR 23.1337. BTW, that FAR isn't why I don't trust them...

Only accurate at empty is NOT what that FAR says.

We have had this discussion before. The gauge must be accurate across its entire range to some unknown percentage difficult to determine under Part 23, but not all aircraft are even certified under Part 23.

Even 23.1337 and that portion around it indicate that there needs to be accuracy and that sub-rule is simply stating that the gauge must be calibrated to USEABLE fuel not total fuel in the tank. That’s a sub-instruction, not the end all be all of gauge manufacture and certification.

Here’s a bunch of research all the way back to 2007 where someone else dug around.

https://www.av8n.com/fly/fuel-gauges.htm#bib-FARs

You can Google that topic and find multiple experts on certification who debunk the multiple myths surrounding that particular sub-instruction to CALIBRATE to zero USABLE fuel.

That’s all that reg says.

 

[FastEddieB]

To a very large extent, I do trust the fuel gauge in my Sky Arrow. This trust has been earned over 11 years and just over 500 hours of observing its accuracy.

Also, my fuel tank is translucent, and the fuel level can be observed once it gets below about 3 gals - on the ground, not on flight. The couple of times I’ve gotten that low, the reading on the gauge coincided with the amount of fuel remaining.

My “quick and dirty” calculation involves conservatively assuming 6 gph and 18 gals fuel (actually 17.8 usable) should keep me in the air about 3 hours. So I plan roughly 2 hour legs. If and when I indicate less than 1/4 tank, I plan on landing for fuel short of my planned stop.

 

[FastEddieB]

If anyone is curious, this is what it looks like:

You can see that by rocking the passenger seat forwards.

 

[coloradobluesky]

Sight gauges are the way to go.

 

[steingar]

Sight gauges are the way to go.

To draggy, they make airplanes slow.

 

[FastEddieB]

To draggy, they make airplanes slow.

Most of the sight gauges I’ve come across are in the wing root.

 

[idahoflier]

Only accurate at empty is NOT what that FAR says.

We have had this discussion before. The gauge must be accurate across its entire range to some unknown percentage difficult to determine under Part 23, but not all aircraft are even certified under Part 23.

Even 23.1337 and that portion around it indicate that there needs to be accuracy and that sub-rule is simply stating that the gauge must be calibrated to USEABLE fuel not total fuel in the tank. That’s a sub-instruction, not the end all be all of gauge manufacture and certification.

Here’s a bunch of research all the way back to 2007 where someone else dug around.

https://www.av8n.com/fly/fuel-gauges.htm#bib-FARs

You can Google that topic and find multiple experts on certification who debunk the multiple myths surrounding that particular sub-instruction to CALIBRATE to zero USABLE fuel.

That’s all that reg says.

Whatever...

 

[Checkout_my_Six]

Only accurate at empty is NOT what that FAR says.

We have had this discussion before. The gauge must be accurate across its entire range to some unknown percentage difficult to determine under Part 23, but not all aircraft are even certified under Part 23.

Even 23.1337 and that portion around it indicate that there needs to be accuracy and that sub-rule is simply stating that the gauge must be calibrated to USEABLE fuel not total fuel in the tank. That’s a sub-instruction, not the end all be all of gauge manufacture and certification.

Here’s a bunch of research all the way back to 2007 where someone else dug around.

https://www.av8n.com/fly/fuel-gauges.htm#bib-FARs

You can Google that topic and find multiple experts on certification who debunk the multiple myths surrounding that particular sub-instruction to CALIBRATE to zero USABLE fuel.

That’s all that reg says.

So...what does CAR 3 say?

 

[Checkout_my_Six]

I'm trying to think if I've ever felt that I was uncomfortably low on fuel in my nearly 3,000 hours, and I can't think of any times. Always given myself margin and made sure not to push limits.

There are negatives associated with having extra fuel, so obviously one must make a balance. But if you have a balance with reserves appropriate for the mission (which are usually more than legal reserves) and contingencies, fuel shouldn't be an issue.

The only negative I can think of is....being on fire.

 

[wayne]

I'm trying to think if I've ever felt that I was uncomfortably low on fuel in my nearly 3,000 hours, and I can't think of any times. Always given myself margin and made sure not to push limits.

I've been uncomfortable twice.

First time in an Arrow and the place I stopped didn't have a credit card reader. No biggie, plenty of fuel. Hopped over to another airport, and I think their fuel price was lower too, so "that will all work out for the good". No fuel there. Now I'm getting lower and spending more time climbing and flying low than I planned on. Hop to another airport, not the closest, but one that I felt most likely to have fuel; didn't want a repeat of the "no fuel, now what" scenario. Fill up, I still had at least 45 min of fuel left after all that. Whew!

The second wasn't even that close, or concerning. It was in a SR22, so an excellent fuel totalizer and we regularly topped off, so it was set well about how much was in it to start. But when both tanks drop below 14 gallons each (if I remember correctly) the low fuel light comes on. That's still plenty of fuel at cruise, but it's a bit unnerving seeing a "low fuel" warning come on. I wasn't anywhere near as concerned as in the Arrow, that darn light is on though, so.... It was years ago, but I think I had started the descent before it came on. Just descending earlier than I would have liked (IFR) and now the fuel burn rate was higher. Still had 1.5+ hrs of fuel left when I fueled up.

 

[Ted]

The only negative I can think of is....being on fire.

More fuel = more weight = less performance. So carrying extra fuel means that your takeoff roll is longer, climb is slower. We think about this especially in the twin world where OEI climb rate is a real consideration. In a single it's not something that's usually thought about, so it's still an issue. The "full fuel every takeoff" idea really stops to make sense once you get bigger than fixed gear single engine trainers, and even then it doesn't make sense since you can run into useful load issues.

So there is a reason not to take off with all the fuel all the time, some good reasons in fact, but it makes far more sense to take off with the right amount of fuel to 1) make the trip and 2) do so comfortably.

 

[Bill Watson]

More fuel = more weight = less performance. So carrying extra fuel means that your takeoff roll is longer, climb is slower. We think about this especially in the twin world where OEI climb rate is a real consideration. In a single it's not something that's usually thought about, so it's still an issue. The "full fuel every takeoff" idea really stops to make sense once you get bigger than fixed gear single engine trainers, and even then it doesn't make sense since you can run into useful load issues.

So there is a reason not to take off with all the fuel all the time, some good reasons in fact, but it makes far more sense to take off with the right amount of fuel to 1) make the trip and 2) do so comfortably.

Agreed. I find myself. Just barely over the line in my RV-10. I have a 60 gallon capacity and was filling it up at practically every stop. I fly off a rough field. After I found that a Vans SB on a fragile nose wheel component exposed the fact that I had a crack in that component, I became less willing to fill up before home field departures when loaded near gross.

On the other hand, full fuel has never been a flight performance issue. I run out of cabin volume before running up against useful load problems. A good power to weight ratio keeps even wet uphill grass takeoff performance comfortable.

Anything bigger in fuel capacity or size would seem to put fuel weight in play.


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[Checkout_my_Six]

More fuel = more weight = less performance. So carrying extra fuel means that your takeoff roll is longer, climb is slower. We think about this especially in the twin world where OEI climb rate is a real consideration. In a single it's not something that's usually thought about, so it's still an issue. The "full fuel every takeoff" idea really stops to make sense once you get bigger than fixed gear single engine trainers, and even then it doesn't make sense since you can run into useful load issues.

So there is a reason not to take off with all the fuel all the time, some good reasons in fact, but it makes far more sense to take off with the right amount of fuel to 1) make the trip and 2) do so comfortably.

yup....but I'm not grown up yet. It's just me in the Bo....so full fuel is a comfort level and a stress reducer.

 

[sarangan]

More fuel = more weight = less performance. So carrying extra fuel means that your takeoff roll is longer, climb is slower. We think about this especially in the twin world where OEI climb rate is a real consideration. In a single it's not something that's usually thought about, so it's still an issue. The "full fuel every takeoff" idea really stops to make sense once you get bigger than fixed gear single engine trainers, and even then it doesn't make sense since you can run into useful load issues.

So there is a reason not to take off with all the fuel all the time, some good reasons in fact, but it makes far more sense to take off with the right amount of fuel to 1) make the trip and 2) do so comfortably.

That would be a good approach if there was a reliable way to count the number of gallons in the tank. In most older airplanes, "full" is really the only reliable level.

 

[Ted]

That would be a good approach if there was a reliable way to count the number of gallons in the tank. In most older airplanes, "full" is really the only reliable level.

It depends on the airplane and it also depends on how many tanks you have. In the planes I've been operating for the past 2,500 hours or so, they pretty much all had 4-6 tanks, which made it easier. In the 414 my typical loads were "Top the tips" (100 gallons), "Top the tips and the wings" (163 gallons), "Top the tips and the nacelles" (140 gallons), and "Top everything" (203 gallons). In the MU-2 it's "Top the inboards" (156), "Top the inboards and outboards" (186), "Top the inboards, outboards, and X in each tip" (186+2x), and "Top it all" (366).

I do understand and agree that with many old piston singles with two tanks that "full" is the only reliable fuel reading, so it's important that you understand your airplane and its capabilities. Obviously erring on the side of less weight but uncertain fuel capacity is bad. I've found the Cessna twins were much better at accurate fuel measurements than the Pipers, and the turbines are generally much, much more accurate including having a totalizer. The old Piper twins were consistently inaccurate on the gauges.

 

[denverpilot]

Whatever...

No, not “whatever”. It’s a flat wrong Old Wives Tale.

Try releasing a new certified aircraft with a fuel gauge that says only “has fuel” and “empty”, and see how far that gets with FAA.

It would meet the stupid oft-repeated garbage about gauges only needing to be accurate at empty.

All it takes is common sense to realize the statement is steamy piles of bovine excrement they keeps getting repeated instead of just saying “old style gauges aren’t super accurate because they were the best electronics available in the 1960s”.

 

[idahoflier]

No, not “whatever”. It’s a flat wrong Old Wives Tale.

Try releasing a new certified aircraft with a fuel gauge that says only “has fuel” and “empty”, and see how far that gets with FAA.

It would meet the stupid oft-repeated garbage about gauges only needing to be accurate at empty.

All it takes is common sense to realize the statement is steamy piles of bovine excrement they keeps getting repeated instead of just saying “old style gauges aren’t super accurate because they were the best electronics available in the 1960s”.

ROFLOL! Yes, whatever...

I understand you're a legend in your own mind but the reality is you have an opinion and it's no better or worse than mine. But your opinion is NOT fact. If you really care about this, I suggest you re-read FAR 23.1337 and let it sink in. If you're still in disagreement, I don't care and you really shouldn't either...

 

[denverpilot]

ROFLOL! Yes, whatever...

I understand you're a legend in your own mind but the reality is you have an opinion and it's no better or worse than mine. But your opinion is NOT fact. If you really care about this, I suggest you re-read FAR 23.1337 and let it sink in. If you're still in disagreement, I don't care and you really shouldn't either...

I did read it. As have numerous other experts and I linked to one of them, and told you there are more.

It’s a SUB requirement of the main branch there and is ONLY a single certification requirement.

It does not limit or control any other certification requirements and the main section there says there must be some (undefined but required UP a level from that single required check and also in OTHER requirements elsewhere in Part 23) of some level of gauge accuracy.

The linked document also points out the TSO requirements for the components themselves (where TSO is applicable) have a SPECIFIC requirement of 3% accuracy.

But you didn’t read it and you don’t understand that one line isn’t a fully controlling sentence about fuel gauges. It’s simply ONE single required calibration test, and that is ALL it is.

Go read the other document. Learn something.

 

[chemgeek]

Not an OWT. Please see FAR 23.1337. BTW, that FAR isn't why I don't trust them...

FAR 23.1337.b is reasonably clear that fuel gauges must "indicate to the flightcrew members the quantity of usable fuel in each tank during flight. An indicator calibrated in appropriate units and clearly marked to indicate those units must be used." (Emphasis added.) This seems pretty clear that the indicator should indicate the actual fuel quantity in some way.

Section 23.1337.b.1 is a sub-rule, under "In addition:" that states "Each fuel quantity indicator must be calibrated to read “zero” during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply" which is intended to ensure that the fuel gauges read zero when there is no more usable fuel, and not when the tank is totally empty.

 

[idahoflier]

I did read it. As have numerous other experts and I linked to one of them, and told you there are more.

It’s a SUB requirement of the main branch there and is ONLY a single certification requirement.

It does not limit or control any other certification requirements and the main section there says there must be some (undefined but required UP a level from that single required check and also in OTHER requirements elsewhere in Part 23) of some level of gauge accuracy.

The linked document also points out the TSO requirements for the components themselves (where TSO is applicable) have a SPECIFIC requirement of 3% accuracy.

But you didn’t read it and you don’t understand that one line isn’t a fully controlling sentence about fuel gauges. It’s simply ONE single required calibration test, and that is ALL it is.

Go read the other document. Learn something.

LOL!

Your own "expert" in your provided link says this: "I don’t know of any official guidance on what is a reasonable tolerance for general-aviation fuel quantity indicators." And further "TSO-C55 is not mandatory for general-aviation aircraft, but we can use it to get a ballpark idea."

"ballpark idea"? Seriously?

The only FAR's specifically pertaining to fuel gauges cited by your "expert" are FAR 91.205 and, drum roll... FAR 23.1337! Now what does FAR 23.1337 say? A lot, but in particular, "Each fuel quantity indicator must be calibrated to read “zero” during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply determined under §23.959(a)".

IDK about your aircraft, but in mine that occurs when the needle is on "E"...

 

[drjcustis]

I think the most telling thing about fuel management is how much of a discussion there is on a thread like this. Over 70 responses (not counting the two debating what the FARs say about fuel gages) and everyone has a small piece of wisdom about how to manage fuel.

With the drone, it’s easy. Fly to 30% battery and think about landing. Mess up and drop to 10% and the computer takes over.

In an aircraft, there are significantly more variables. Accurate measurement, reliability and reproducibility of that measurement, tracking fuel, fuel flow, engine management, power requirements, LOP/ROP, headwinds-tailwinds, diversions, altitude management, and on and on.

Just today, I did a go around due to weather with 18 gallons left in a PA32. The fuel split into 4 tanks. Makes for interesting management.

Underestimation of the complexity of fuel management and limited training on those complexities likely contributes to many of those accidents.


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[idahoflier]

Over 70 responses (not counting the two debating what the FARs say about fuel gages) and everyone has a small piece of wisdom about how to manage fuel.

Agree. My apologies to the forum for hijacking the topic...

 

[asicer]

Over 70 responses (not counting the two debating what the FARs say about fuel gages) and everyone has a small piece of wisdom about how to manage fuel.

I'd say that's the result of either expectation bias or cognitive capture, which happens to contribute to the psychology of fuel mismanagement.

 

[Rushie]

One of my former CFIs had a fuel exhaustion accident where I think psychology played a part. He had borrowed our C172 many times to make a certain trip, and our 172 had extended range tanks. One day he called me and asked if he could take our plane but I told him no, it wasn't available. So he obtained another 172 but it had standard tanks. Among his passengers was a friend who was a student pilot and one of them visually looked into one tank and the other, the other, but did not stick them. They "appeared" full.

He almost had enough to make it back home. The engine quit and he had to put it down in a field, at night, just a mile or so from the end of the runway. Clipped a power line and flipped upside down but he and his passengers survived with minor injuries, except one broken leg.

It seems obvious how he screwed that up, but I think part of it was that he was so used to making that same trip in our plane, which not only had more fuel capacity, was always topped off when left in the hangar. The rental he took that lived on the ramp had been filled, but someone could have taken it up for a couple of touch 'n goes; he should not have assumed "appeared full" meant really full.

It's almost as if he forgot he wasn't in our plane, though the real cause was he did not pay close attention to fuel management, including redoing his calculations for smaller tanks and verifying how full those tanks actually were. This would fall under "complacency" I would think. It's easy not to redo the math every time you take the same plane on the same trip on similar nights with similar winds etc. But had he been in the habit of carefully planning the fuel each and every trip, he wouldn't have messed this up.

This sort of thing is why I'm a believer in doing checklists literally item by item every time. Psychologically, we become creatures of habit. A background context develops when we repeat the same activity over and over. Then when we vary one thing, the familiarity of the context may lull us into failing to account for the variable. This is of course subconscious- naturally he knew it was a different plane. But it was night, he was tired, everything else was the same, he even had a memory of talking to me on the phone, just like he did on the days he took our plane, so the context was mostly intact, and his subconscious was giving the message that all was well, until suddenly it wasn't.

 

[deyoung]

The only time I ever ran a tank dry was a complete case of distraction. I wasn't short on fuel overall, but was distracted enough to neglect switching tanks as needed (Cherokee-235). I was flying from Arizona to Burbank, and it was my first experience in the busy SoCal airspace, and I had an intermittent radio failure shortly after being handed off to SoCal. I was focused on troubleshooting the radio issue, and stressed about maybe not being able to communicate with the (very busy) SoCal controllers, and completely forgot about managing fuel until the engine wound down and the nose pitched down.

Oh ****... switch tanks, fuel pump on, hold breath for about an hour (ok, maybe five seconds really) and it all comes back to life and we're good, but I won't forget that anytime soon. And my wife now believes it is her job to monitor fuel gauges, which is probably a good thing too.

 

[denverpilot]

LOL!

Your own "expert" in your provided link says this: "I don’t know of any official guidance on what is a reasonable tolerance for general-aviation fuel quantity indicators." And further "TSO-C55 is not mandatory for general-aviation aircraft, but we can use it to get a ballpark idea."

"ballpark idea"? Seriously?

The only FAR's specifically pertaining to fuel gauges cited by your "expert" are FAR 91.205 and, drum roll... FAR 23.1337! Now what does FAR 23.1337 say? A lot, but in particular, "Each fuel quantity indicator must be calibrated to read “zero” during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply determined under §23.959(a)".

IDK about your aircraft, but in mine that occurs when the needle is on "E"...

That was just the first of many sources of folks who had all the research killing the dumb OWT on various sites for well over a decade. I said that in my post. My challenge to you was to do more homework, not do it for you.

If you do any actual research into it, you’ll find you are arguing that a single required calibration test for certification is the only controlling factor for fuel gauges in all of published FAA documents, which is patently and completely false.

But try it. Certify an airplane under Part 23 that has two lights and meets your criteria you think is the only control on fuel quantity gauges. “Have fuel” and “empty”.

FAA will laugh you out of the room with your deficient quantity light system. Obviously.

The gauge thing is an OWT. It’s clear when you apply your supposed single standard for gauges in the most absurd way, two lights. It would never pass. Not in a million years. And the old designers of the crappy old (but reasonable and best at the time) gauges would have also been laughed out of the room if they tried it.

With the publication of the TSO, which we all know isn’t mandatory, it’d be thrown at you today if you tried it. Back in the early days people still had a modicum of common sense and knew two lights wouldn’t fly. They didn’t need a ten inch thick document to know it either. But NOBODY expected a gauge not to have some semblance of accuracy when reading something other than empty.

It’s an utterly stupid argument to claim airplane designers and CAA/FAA officials were that stupid just because they didn’t write down a thirty page document on how something as simple as a gauge should work. And do work.

They’re not as inaccurate as the OWT pushers would want one to emotionally believe by pointing out omissions in documentation. They just want to hang their hat on the idea that FAA says the gauges don’t have to be accurate in any way, and clearly that’s flat false. FAA knew and still knows today what the typical resistive gauges can and can’t do.

They and the designers aren’t particularly worried about witting it into the standard because nobody would BUY an airplane with this theoretical dumb two light system. And they wouldn’t approve it anyway, not even for a stubborn jerk of a designer who demanded they only have one line of requirements for the thing.

They’ll just laugh and tell him to replace it with something non-stupid.

 

[FastEddieB]

I'd say that's the result of either expectation bias or cognitive capture, which happens to contribute to the psychology of fuel mismanagement.

Am on-topic post!

Hallelujah!

 

[FastEddieB]

Analogy...

I would have said I was not the type of person to ever hook up an aircraft battery backwards...until I did.

I had so many assumed fail-safe procedures to avoid doing so, until one day...oops!

I have a friend that built 2 homebuilts, so definitely NOT lazy. The second needed building after he ran out of fuel in the first on the way back from the Bahamas and ditched at sea. When I related my battery fiasco to him, he told me that, prior to his incident, he would have placed himself firmly in the camp of those who would never run out of fuel. Until he did.

Just food for thought - pride goeth before a fall.

 

[steingar]

In case anyone was worried I had some (very expensive) fuel put in my aircraft last night. I'll make my cheap gas stop in Indiana.


That's assuming it doesn't rain all day.

 

[sarangan]

One of my former CFIs had a fuel exhaustion accident where I think psychology played a part. He had borrowed our C172 many times to make a certain trip, and our 172 had extended range tanks. One day he called me and asked if he could take our plane but I told him no, it wasn't available. So he obtained another 172 but it had standard tanks. Among his passengers was a friend who was a student pilot and one of them visually looked into one tank and the other, the other, but did not stick them. They "appeared" full.

He almost had enough to make it back home. The engine quit and he had to put it down in a field, at night, just a mile or so from the end of the runway. Clipped a power line and flipped upside down but he and his passengers survived with minor injuries, except one broken leg.

It seems obvious how he screwed that up, but I think part of it was that he was so used to making that same trip in our plane, which not only had more fuel capacity, was always topped off when left in the hangar. The rental he took that lived on the ramp had been filled, but someone could have taken it up for a couple of touch 'n goes; he should not have assumed "appeared full" meant really full.

It's almost as if he forgot he wasn't in our plane, though the real cause was he did not pay close attention to fuel management, including redoing his calculations for smaller tanks and verifying how full those tanks actually were. This would fall under "complacency" I would think. It's easy not to redo the math every time you take the same plane on the same trip on similar nights with similar winds etc. But had he been in the habit of carefully planning the fuel each and every trip, he wouldn't have messed this up.

This sort of thing is why I'm a believer in doing checklists literally item by item every time. Psychologically, we become creatures of habit. A background context develops when we repeat the same activity over and over. Then when we vary one thing, the familiarity of the context may lull us into failing to account for the variable. This is of course subconscious- naturally he knew it was a different plane. But it was night, he was tired, everything else was the same, he even had a memory of talking to me on the phone, just like he did on the days he took our plane, so the context was mostly intact, and his subconscious was giving the message that all was well, until suddenly it wasn't.

I had a similar experience, but luckily did not end up in the statistics. I was giving instruction for a commercial student in a 210. One time the engine quit, luckily near an airport, and I was able to take control and land it uneventfully. To our horror, we discovered that it was out of fuel. How did this happen? The fuel gauges on this plane were known to be flaky. When the gauges were oscillating between full and empty during initial taxi out, I asked the student if he checked the fuel, and he confirmed that it was full. It turns out he checked the fuel by opening the cap and looking inside. He did not use the dip stick because it looked obviously full. This 210 had very shallow tanks, and the difference between full and empty is just a few inches. It was an innocent mistake, and combined with the flaky gauge, contributed a chain of accident factors, but we still made it on a runway due to nothing but dumb luck. Since then, I always personally check the fuel level when I fly with a student. This is something I believe every CFI should be doing regardless of who the student is or their certificate level.

 

[jaymark6655]

Always, always, always stick all tanks. I guess part of me wants to make sure that stick still works so I need to test it on that full tank to make sure it is calibrated right, lol. I do it even when I just plan on doing three loops in the pattern and the tanks look full. I track my xcnty with a stop watch, but the left tank on the rental I take also says empty almost all the time even with 20+ gallons in that tank. Haven't had a leg go long, but I have hit check points earlier than planned which always freaks me out for some reason. I spend a good amount of the flight wondering if I flew it at the wrong power settings/using more fuel than planned to go faster even though I haven't touched any controls and they are set right where I wanted them. I have even stopped and sticked the tanks during a planned break just to see if I was burning more fuel than planned because I was so worried about it and then sticked it again at my destination. Had two extra gallons per side versus what I had planned to end with. As I start to make longer flights, starting with less fuel due to passengers, I am constantly worried that I will make a mistake in this area. I guess my view on the reserve is that I need to do everything in my power to not burn that fuel and restick and recalc the remaining trip if I make an unplanned stop. It might take some time, but walking/driving because I put down somewhere off airport takes a lot longer and cost more.

 

[sarangan]

Always, always, always stick all tanks. I guess part of me wants to make sure that stick still works so I need to test it on that full tank to make sure it is calibrated right, lol. I do it even when I just plan on doing three loops in the pattern and the tanks look full. I track my xcnty with a stop watch, but the left tank on the rental I take also says empty almost all the time even with 20+ gallons in that tank. Haven't had a leg go long, but I have hit check points earlier than planned which always freaks me out for some reason. I spend a good amount of the flight wondering if I flew it at the wrong power settings/using more fuel than planned to go faster even though I haven't touched any controls and they are set right where I wanted them. I have even stopped and sticked the tanks during a planned break just to see if I was burning more fuel than planned because I was so worried about it and then sticked it again at my destination. Had two extra gallons per side versus what I had planned to end with. As I start to make longer flights, starting with less fuel due to passengers, I am constantly worried that I will make a mistake in this area. I guess my view on the reserve is that I need to do everything in my power to not burn that fuel and restick and recalc the remaining trip if I make an unplanned stop. It might take some time, but walking/driving because I put down somewhere off airport takes a lot longer and cost more.

Even the stick is not always reliable. Because I have to plug the hole with a finger, I get slightly different reading every time. Good thing is that it will almost always under-read so you can't go too wrong. This is one good thing about low-wing tanks. On a high wing, standing on one foot on the strut while supporting your weight with one hand, dipping the stick becomes a hurried activity.

 

[denverpilot]

Even the stick is not always reliable. Because I have to plug the hole with a finger, I get slightly different reading every time. Good thing is that it will almost always under-read so you can't go too wrong. This is one good thing about low-wing tanks. On a high wing, standing on one foot on the strut while supporting your weight with one hand, dipping the stick becomes a hurried activity.

That breaks the “If you have to hurry, it’s probably not being done right” rule for me.

Find a ladder.

Obviously for those of us in a hangar this is easier, but I’ve seen lots of stepladders chained down to the “stuff box” outside on the lines of mostly Cessnas at local Flight schools. If the school has a box for oil, rags, cleaning material, they should have a step ladder attached to it. Basic tool needed for high wings.

Many of the aircraft don’t have the strut steps installed and shouldn’t be climbed on anyway. If I saw someone climbing on my 182 strut, I’d go push them off and ask them WTF they thought they were doing.

I haven’t been to an airport yet that didn’t have a stepladder around.

take that back, I’ve been to one crop duster strip that the buildings were locked where there probably was one, but couldn’t get to it. That was a diversion and I really didn’t have any concerns that there wasn’t enough fuel on board, since the original flight plan was for five hours and the landing was made at hour number two.

A cheap two step folding stepladder is plenty big and fits in the baggage area if one thinks they’re going somewhere the fuel truck won’t have a ladder hanging from the back of it that can be borrowed. That’s usually the go to place for finding a ladder on nearly ANY ramp if there’s not one sitting right at the fuel pumps.

 

[drotto]

And some of us have un-stickable planes. I have a PA32R-301. That operates as a two tank plane but technically has four tanks. Yes you can see and stick the outer tanks, but that only accounts for 32 gallons total. The inner tanks are inaccessible to viewing, so I have to rely on the site glass gauges on the wing. I have heard that gauge is accurate.

With that said, I must trust that site glass and know if I see any fuel in the outer tank, I have at least 35 gallons in that wing.

Sent from my SM-G950U using Tapatalk

 

[asicer]

And some of us have un-stickable planes. I have a PA32R-301. That operates as a two tank plane but technically has four tanks. Yes you can see and stick the outer tanks, but that only accounts for 32 gallons total. The inner tanks are inaccessible to viewing, so I have to rely on the site glass gauges on the wing.

That reminds me, 50 gallon DA40's are the same way. Except the sight glass is not an integral part of the fuel system. You have to place it against the wing and press a hose against a fuel drain. It is a major pain to use and makes a big mess when you're done.

One guess as to why Diamond did it this way is to play psychology games with fuel management: "I can't tell how much fuel is in there and I don't want to deal with the Rube Goldberg measurements so I'll just add fuel."

 

[Salty]

The couple of times I've been agonizingly close, it was like falling into a kind of "coffin corner" trap.

What I mean is, the closer I got to my planned destination, the more it seemed like I could "probably" make it and the more I'd hate to stop just a few miles short for a few gallons.

Wow, I totally relate to this on one flight. I was running late with 30 people waiting for me, was "low on gas". The closer I got, the more worried I got, AND the more I didn't want to stop because I was "almost there, stopping so close to home is silly".

I calculate extremely conservatively, and still had theoretical fuel left, but I really should have stopped and put more in.

The next day I checked the tanks to see how close I was. One tank was on fumes, the other had more than 6 gallons usable in it, so I still had more than 1/2 hour of fuel left, but I don't like getting that low. I shouldn't have let external pressures change my behavior.