Fuel Planning instruction

jdwatson

jdwatson

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I was looking thru NTSB archives at all the fuel starvation accidents, so that got me to thinking how is fuel planning taught ?

Is seems like to me, most students get a plane with full tanks, never really fly near the distance to even worry about fuel planning in terms of endurance, power settings, winds aloft and etc.

So to that end, what were you taught and for CFI, what do you teach ?
 
jdwatson said:
So to that end, what were you taught and for CFI, what do you teach ?
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To use the book and verify your calculations with real fuel consumption.

For instance I know my plane averages about 8gph. Book says 8.5gph and I plan my flights using 9gph. For some reason I always end up with more fuel in my tanks than what my flight log says. :rolleyes:
 
Being a new pilot/owner I think the planning end the flight was good as far as fuel usage goes but they teach "By the book numbers" and not real world (meaning the numbers they use are a bit low). On the flight end I don't feel that enough was taught on leaning the engine and other ways to conserve fuel. To much flying was done with the mixture "full rich" which gives higher than book fuel usage. If this attitude is then used for some long distance X/C the student/new pilot has a real chance of becoming a fuel starvation stat.
 
I usually plan on about 10 gph for the initial climb, then 0/hr from there until landing...

Seriously, I teach my (power) student to take book numbers, add a gallon an hour, and plan for that.
 
As a student - I was taught to plan by using the worst case (full rich) fuel burn for the climb and descent portion. As far as cruise, I used the intermediate values between full rich and best economy (assuming I would remember to lean). I then assumed a 1 hr reserve. I guess I'll always choose the conservative route on fuel planning.

In reality, I may never make an XC flight that reaches the limits unless I don't refuel for the return flight. However, I am very careful when taking the A/C out for a local flight if the tanks are below the tabs. I assume that at or above the tabs I have a known amount of fuel (plenty for a local flight). But below the tabs, who knows?

Your question gets me to wondering how many fuel starvation incidents occur on the return leg of an XC?
 
Most planes I fly burn about 8 gph. I usually plan for 9 gph.

The last flight that I did was of some distance. Both times that I purchased fuel I was able to predict how much I had left to the GALLON.
 
jdwatson said:
So to that end, what were you taught and for CFI, what do you teach ?
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Begin every flight by checking the fuel tanks visually and with a dipstick.
Write down in aircraft flight log the amount of fuel available.
Estimate time and distance available compared with destination based upon experience and forecast winds.
Check fuel gauge level after starting engine and compare with estimate.
Check fuel gauge level after every time the compass is compared with heading indicator (about every 10 minutes)
Re-evaluate destination decision if fuel gauge level differs from estimates.
End every flight with estimate of fuel in tanks.
 
jangell said:
The last flight that I did was of some distance. Both times that I purchased fuel I was able to predict how much I had left to the GALLON.
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Back when I was flying a Baron on charter, I could get within .2 :)

Fly safe!

David
 
Great responses so far... It wasn't until I did my commercial did I have an appreciation for W&B with fuel amounts. As a student pilot, I always planned to take off with full tanks. Since the flight was either solo or dual, I never had to do much planning after the initial calculations.

Gratefully, I was taught leaning early on. We use the POH as reference and planning. If you beat the POH numbers, good on you. If you're not getting the book numbers, then find out why.

When I started making longer X-C trips and flying IFR is when I really learned fuel planning. For instance: IFR 500nm trip, 150KTAS, 19gph, 88 gals usable in our T206H... Do you try for a non-stop or plan a fuel stop along the way ? Proving to yourself with numbers is the real question/problem at hand. I had no appreciation for it as private pilot flying missions well within the endurance envelope of my favorite 172R.
 
Way back in my student pilot days, I was basically taught the red knob was for shutting the engine down. Therefore, the fuel planning used for cross countries was an exercise in stupidity. I was not taught how to lean an engine until I taught it to myself as an aircraft owner with an instrument rating and about 150 hours.

Fast forward 15 years. I was checking out in a new airplane at a new FBO and the instructor asked me what I was doing when I pulled the mixture back when I leveled off at 3000 feet. Duh. Some things never change.
 
Ken Ibold said:
Way back in my student pilot days, I was basically taught the red knob was for shutting the engine down. Therefore, the fuel planning used for cross countries was an exercise in stupidity.
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Ditto pretty much what Ken said. It would be better if the FBO handed you the keys with an unknown quantity of fuel in the tanks. From your first flight, the lesson should be to determine how much fuel is in the tanks, and how much are you going to need for this flight (with reserves). There ought to be a penalty (in how often you buy the CFI lunch or some such "soft" penalty) for bringing back a plane with too much or too little fuel.

That would help to create a fuel awareness that doesn't really exist today.

-Skip
 
As a CFI, I avoid having my students use checkpoints that are spaced unrealistically (ridiculously) close together on the navigation log so that I can emphasize that these checkpoints are primarily for fuel calculations, not navigation. When I make them do them closer than needed for reasonable fuel planning, I let them know that it's busy work for training purposes
 
Ken Ibold said:
Way back in my student pilot days, I was basically taught the red knob was for shutting the engine down. Therefore, the fuel planning used for cross countries was an exercise in stupidity. I was not taught how to lean an engine until I taught it to myself as an aircraft owner with an instrument rating and about 150 hours.

Fast forward 15 years. I was checking out in a new airplane at a new FBO and the instructor asked me what I was doing when I pulled the mixture back when I leveled off at 3000 feet. Duh. Some things never change.
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The flight school I belong to holds nearly quarterly "How to lean" seminar, including DA considerations. They're free and include a certificate for "free dual" time (you pay for the rental) to put it in practice. The owner of the school is a proponent of aggressive leaning on the ground and proper leaning in the air. I'm sure this is a part of the instruction for primary students.

I'm sure a part of it is protecting the bottom line, fouled plugs and rising fuel costs come to mind. I felt it was well presented and reinforced what I learned during my commercial rating.
 
Skip Miller said:
Ditto pretty much what Ken said. It would be better if the FBO handed you the keys with an unknown quantity of fuel in the tanks. From your first flight, the lesson should be to determine how much fuel is in the tanks, and how much are you going to need for this flight (with reserves). There ought to be a penalty (in how often you buy the CFI lunch or some such "soft" penalty) for bringing back a plane with too much or too little fuel.

That would help to create a fuel awareness that doesn't really exist today.

-Skip
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Interesting idea... :yes:
 
smigaldi said:
To use the book and verify your calculations with real fuel consumption.

For instance I know my plane averages about 8gph. Book says 8.5gph and I plan my flights using 9gph. For some reason I always end up with more fuel in my tanks than what my flight log says. :rolleyes:
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Ditto
 
I sprung the money for a fuel totalizer. Most of my trips are long, X-Cs where I want to stretch fuel range. It's really nice to have the totalizer and an engine monitor, because leaning with the turbocharger can result in a 1 GPH or more fuel variation with relatively small changes in the TIT. I don't know how folks manage the engine effectively with the basic factory instruments.
 
For every long cross country flight I've ever done, it's been very easy.....2.5 hours maximum legs, then refuel. It's good on the legs, back, bladder and mind.
When doing the traffic watch, we are often up there for over 4 hours at a time in a warrior. Full fuel to start, lean like crazy, and pull the power back to 2000 rpm. We are never far from an airport with fuel either.
 
Dipstick the tanks (compare to fuel guages for laughs) before takeoffs if not topped off, and when topping off, calculate how much fuel each tank should take based on previous flight profile, then compare that with the fuel pump meter. Self-reward &/or punish as appropriate.
 
I guess you can summarize what I teach in four basic rules.

1. The book figures are "best case." They assume perfect plane, perfect engine, perfect prop, and perfect leaning, and neither your plane, nor your engine, nor your prop, nor you are perfect. Get to know what your plane really burns when you fly it, and plan accordingly.

2. One of the three most useless things in flying is fuel in the fuel truck. Unless you really need that extra weight allowance for payload, always carry all the fuel you can fit in the tanks, because the only time you can have too much fuel is when you're on fire. (Note: Yes, I know about max landing weight limitations, but the planes Student Pilots fly almost never have them.)

3. The FAA minimums are bare bones legal mins, and give you no real allowance for any error or change in conditions. If you ever find yourself in a situation where you can expecte to land at your planned destination with less than an hour left in the tanks, it's time to start planning a landing somewhere close enough that you'll still have an hour left.

4. Fuel tank gauges lie. Know what your plane burns, use your clock, and track how much time you've flown out of each tank. Believe the lowest of clock, gauges, or gut feel.
 
I try to say all the above and hope they learn. I also mention a very high percentage (I forget the actual number but believe it's around 75%) of forced landings are fuel management problems.

One other thing I do is on the solo cross countries I have them fill the tanks, fill them when they return and compare the the amount added with the estimate from their flight plan. Only time we can't do this is when the next scheduled flight needs less fuel for W&B, then we use the calibrated dipstick.

Joe
 
Pretty simple on my part, my airplane holds more fuel than my butt or bladder can handle. So I top off the tanks when I stop for a break. Which is about 2.0 hrs.:D
 
Learned to fly by NEVER leaning.
Bought the Cherokee six and was told by the previous owner he usually burned 13gph. Took my first X-C in it averaged 15gph. Now that I learned better leaning practices I average 13.5 and plan for 15gph.
I keep track by the clock and never land with less than 1hr in the tanks.

With my limited experience my conclusion is it takes time to get to know what you are flying. So I would be very careful getting in an new air plane and going on a x-c.

I also belive it would have been much better if my training included more fuel management.
 
I was taught to know what you start with, time the tanks, switch at regular intervals, lean aggressively 50-100 ROP (the "feel method" and/or engine analyzer), and be ready to pull over if the fuel burn is higher than estimated. Fuel gages are only accurate at 0 (although the IAR fuel meters are fairly precise below 10 gallons).
 
Steve said:
Fuel gages are only accurate at 0 (although the IAR fuel meters are fairly precise below 10 gallons).
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Actually, sometimes not even then. Saw a plane in the shop with dry tanks and the guages showed over 1/4 tank each side!

Why even put them in an aircraft when they're so useless?
 
wsuffa said:
I sprung the money for a fuel totalizer. Most of my trips are long, X-Cs where I want to stretch fuel range. It's really nice to have the totalizer and an engine monitor, because leaning with the turbocharger can result in a 1 GPH or more fuel variation with relatively small changes in the TIT. I don't know how folks manage the engine effectively with the basic factory instruments.
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Simple answer is "you can't". I think for any travelling or working aircraft, the fuel totalizer is a must along with all cyl EGT, CHT &TIT if applicable. That's the only way to really track what your engine is doing in flight.
 
Steve said:
lean aggressively 50-100 ROP (the "feel method" and/or engine analyzer),
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50-100 ROP is not leaning "aggressively." If you use Lycoming's "lean to rough, enrich back to smooth" method, you'll end up right around peak EGT. I've checked this with EDM-700/760 engine analyzers over more than 1000 hours on Lycoming engines. You have to enrich further than that to get to 50-100 ROP unless you have unusually uneven fuel/air distribution to the cylinders.
 
Dave Krall CFII said:
Actually, sometimes not even then. Saw a plane in the shop with dry tanks and the guages showed over 1/4 tank each side!

Why even put them in an aircraft when they're so useless?
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I hope it was in the shop to fix those fuel gauges. I thought they *had* to read zero when empty.
 
Mark mentioned checkpoints and students using unrealistically close ones. What do y'all teach/use ? I fly airways a lot, so I like to use VORs or change-over points as checkpoints if they make sense (aka not too close together).
 
Well, that may be your experience, but using a 6-channel EI UBG-16 I find I get 100 below peak using the "feel" method on the IO-540 on the leanest cylinder. I go a couple of clicks rich of "smooth" just like my instructor in the C150 showed me with the O-200. He had a few hours, too. And the -540 will run rough in the climb above 2500' indicated if it is not leaned, full rich makes a noticeable "rough", so I use the term "aggressively" to also include adjusting leaning all the way up to cruise, which many instructors do not advise.


Ron Levy said:
50-100 ROP is not leaning "aggressively." If you use Lycoming's "lean to rough, enrich back to smooth" method, you'll end up right around peak EGT. I've checked this with EDM-700/760 engine analyzers over more than 1000 hours on Lycoming engines. You have to enrich further than that to get to 50-100 ROP unless you have unusually uneven fuel/air distribution to the cylinders.
Click to expand...
 
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Steve said:
Well, that may be your experience, but using a 6-channel EI UBG-16 I find I get 100 below peak using the "feel" method on the IO-540 on the leanest cylinder. I go a couple of clicks rich of "smooth" just like my instructor in the C150 showed me with the O-200.
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That highlighted part explains it -- you're enriching past the "smooth" point. If you enrich only to "smooth," the way Lycoming recommends, you'll probably be right around peak.

And the -540 will run rough in the climb above 2500' indicated if it is not leaned, full rich makes a noticeable "rough", so I use the term "aggressively" to also include adjusting leaning all the way up to cruise, which many instructors do not advise.
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Unless that's on a day so hot it's 5000 DA at 2500 MSL, if your engine runs noticeably rough in a full power climb at 2500 MSL, something in the injection system probably needs adjusting, because that shouldn't happen below 5000 DA. Consult your mechanic.
 
Interestingly enough, my mechanic did find one injector that needed cleaning during the yearly inspection on Friday. I'm waiting to get it off the jacks to see if it makes a difference.
 
jdwatson said:
I hope it was in the shop to fix those fuel gauges. I thought they *had* to read zero when empty.
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I think that's somewhat of a myth. I believe that this is part certification requirement and part service instruction. In the shop manuals I've seen, there is something that says to adjust the gauge/sender so that the gauge reads 0 when the tank is empty (no useable fuel) but I've never seen anything that says this calibration should be checked during an annual inspection.
 
lancefisher said:
I think that's somewhat of a myth. I believe that this is part certification requirement and part service instruction. In the shop manuals I've seen, there is something that says to adjust the gauge/sender so that the gauge reads 0 when the tank is empty (no useable fuel) but I've never seen anything that says this calibration should be checked during an annual inspection.
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Probably not, but remember that part of the definition of "airworthy" is that the aircraft conforms to its original type certificate.

If somebody's flying an airplane that's not going to read properly at empty, it's probably going to be "more off" at non-empty readings than it should be, and the pilot should squawk it. IOW, if you get back from your 2-hour cross country, and the gages are still reading full, it probably isn't going to read properly when it's empty.

I think that the reason it's only required to read accurately at empty is simply the shape of the tanks and the changing attitudes of the airplanes. The analog float-type systems in most light airplanes simply aren't capable of nonlinear indications (i.e., halfway down in the tank is still 2/3 capacity in level flight, more or less in climbs or descents). We teach and treat them like they aren't required to operate except when empty, but in reality they're just not accurate except when empty.

Fly safe!

David
 
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