The trials and tribulations of fuel vs load

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drotto

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drotto
My biggest disappointment in GA (newly minted PPL) has been coming to terms with the fact that most 4 seats planes are 3 seaters, and most sixes are fours, if you want any baggage. So this has left me with some practical questions in solving this load vs fuel riddle.

1. How much fuel do you feel comfortable leaving behind? I figure most of the time passengers will not tolerate more than 2 1/2 to 3 hours without a pit-stop. I fully realize that commercial planes fill for the needs of the flight, not to capacity. Mentally, I am inexperienced and like the idea of full tanks. I know I have to get over that. With the Saratoga I am now learning in, in order to carry 6 and something resembling a bag about 70 gallons is max fuel. Granted that is about 4 hours of fuel.

2. If you are a good little plane owner and follow the FAA recommendation to fill those tanks when you finish, how do people deal with getting fuel out? When you get it out what the hell do you do with it, that stuff is expensive?
 
There isn't much point to filling your own plane when you're done. It's helpful if you're paying a dry rate, as that's an easy benchmark.

Even renting wet, it's unusual to find long range aircraft filled to the gills. If it has tabs, those are commonly used.

Fill it when you need it and know the load.

If you're flying low altitudes, I'd fill it to max gross before leaving. If performance is a concern, such as in the mountains, leave it 10% under.

Some airplanes have a max landing weight smaller than max takeoff. If the trip is short, use the landing weight to determine load.

The FAA's idea that you'll distill water into an empty tank might be an issue if the airplane sits a while, but I NEVER sump water out of a plane that doesn't have leaky fuel caps. Not even 182s filled to tabs and below all the time (CAP).
 
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It's funny, because when you start flying twins, it becomes common to leave behind whatever you don't need because it is a safety factor in SE performance. Well, truth is, it's also a safety factor in a SE plane as well. Any fuel that you don't need that you fly with, reduces your performance, and increases the hazard in an emergency. If I need full tanks, I fill the tanks. If I need an hour of fuel, I take two hours. I don't fuel until I know what flight I'm prepping for.
 
I've not had to game my fuel yet. If I'm taking people cross country it's usually myself, wife and two kids.
 
If you own the plane you learn to trust the numbers. I have a 182 and routinely do 200-300nm trips with 2-4 people and bags. Running the numbers becomes more critical. I will always fly will full tanks when I can...but that is not always practical to get everyone and bags in and be under gross.

I also NEVER top off the tanks when I return. I have been burned several times wanting to do an unexpected flight and would be overweight with full tanks. Put in what I need at the start of each flight. Sometimes full, sometimes not. It is all a delicate balance game.

But you are correct. There are very few single engine planes that can take all seats filled, tanks filled and some baggage without being an NTSB report.
 
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Then how do you accurately gauge fuel amount. Full is easy, Hey look its at the rim that is max fuel. The larger tanks you can not see that far down, especially planes like the Pipers which use 4 tanks that work as 2 tanks. You can not see that inboard tank at all. Now the plane does have the sight glass that in theory reads 35 gallons when the inboard tanks are full up. Then the outboard bladder holds another 16 gallons. You can kinda see into that one. I doubt the calibrated stick would work in this plane. Then to top that off, so many pilots claim fuel gauges are crap.
 
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OkieAviator said:
I've not had to game my fuel yet. If I'm taking people cross country it's usually myself, wife and two kids.
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Even so, if you fly 3 hour legs due to potty breaks etc, it's a negative safety factor to carry 6hrs worth of fuel, at least in the lower 48 or Europe.
 
I have only owned my plane for a few months, but so far, I've never even filled the tanks to the top. My 182 will hold 84 gallons, but I usually just put about 60 in it when I "fill up". That's still about 5 hours of flying. Carrying 500 lbs. of fuel just seems silly if I don't need anywhere near that for most flights. With the family aboard and some baggage, 60 gal puts me close to gross anyway. Personally, about 3 to 3.5 hours per leg is about all I can stand.

That being said, when I get the mogas STC, I'll likely carry as much fuel as I can just because mogas is a little scarce.
 
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drotto said:
2. If you are a good little plane owner and follow the FAA recommendation to fill those tanks when you finish, how do people deal with getting fuel out? When you get it out what the hell do you do with it, that stuff is expensive?
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*please note I have no experience in needing to decide how much fuel to take on a trip. Once I get more familiar with the plane and truly know how much I can expect to burn, and run into a situation where I need to lose fuel to carry people/bags I will carry less fuel.

But at any rate.
there's always burning it off on the ground before you go depending on how much you need to get rid of.
You could also ask the guy flying before you to not top it off (I've had to do this and used a rough number for the amount of fuel I used to pay for the rental).
I don't think there's a problem with siphoning any out (although I honestly don't know either.....)

Sorry I have no real world scenario experience, just a few things I've thought of that you all probably already knew.
 
I only carry what is needed for the flight(plus required reserves). My flight planning is conservative to account for changes in winds. Haven't had it happen but if during the flight the winds are WAY worse than planned, or for some reason I am burning more than planned I just land and put more in. It took a little bit for me to get over the full tank comfort factor you described. I think that came from me flying a rental which was always full and it was just the instructor and I. I think you will find that topping it off and then pulling out what you don't need is going to be a HUGE pain.
 
Any plane that can fill the seats, baggage, and fuel tanks simultaneously, would be a poorly designed plane. It needs either more tanks or more seats.
 
I top off after almost every flight for the sake of keeping the bladders wetted but I don't have long range tanks. It hasn't bitten me yet. My flying habits and loading are likely not the norm though.
 
timwinters said:
I top off after almost every flight for the sake of keeping the bladders wetted but I don't have long range tanks. It hasn't bitten me yet. My flying habits and loading are likely not the norm though.
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Makes no difference. A quart of fuel is as good as 50 gal as far as bladder longevity.
 
One of the problems with how most places fuel IMO.

Last place where I was teaching rented dry, students were to return the plane with 1/4 tanks.

You would plan your flight out and fuel accordingly, over fuel and you just gave away some gas, under fuel and you had to fuel the plane back to 1/4 before you could go home.

Really helped teach proper fuel management.

With my aircraft, I rarely will top them off.
 
JHW said:
Any plane that can fill the seats, baggage, and fuel tanks simultaneously, would be a poorly designed plane. It needs either more tanks or more seats.
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:thumbsup:

When I'm flying more than two passengers, there is no way in heck I need to bring 5 hours of fuel.



When its just me and one passenger, a 5 hour leg is about right, plus about 200 pounds of baggage and a 30 pound dog.
 
JHW said:
Any plane that can fill the seats, baggage, and fuel tanks simultaneously, would be a poorly designed plane. It needs either more tanks or more seats.
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The 182 or the Piper Dakota (Cherokee 235 line) are bad planes then? Both have great useful loads, and can often fill the seats, the fuel, and have a little left over
 
MAKG1 said:
Even renting wet, it's unusual to find long range aircraft filled to the gills. If it has tabs, those are commonly used..
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We leave the Mooney filled to the tabs, 50 gallons, which at minimum is 4hrs + 1hr reserve. That fulfills 90% of most of the missions, both distance and payload.

That said, I've left out on two hour trips with 30 gallons onboard when I've needed to fill all seats. Just work the numbers.
 
drotto said:
The 182 or the Piper Dakota (Cherokee 235 line) are bad planes then? Both have great useful loads, and can often fill the seats, the fuel, and have a little left over
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Yup. A 182 could have been designed with 5 or 6 seats and been more useful.

And only the really under-equipped ones can take that load. Put a good GPS and autopilot, and all the extra panel doodads that people like for IFR, plus full fuel, and you're not fitting four adults in there.
 
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JHW said:
Any plane that can fill the seats, baggage, and fuel tanks simultaneously, would be a poorly designed plane. It needs either more tanks or more seats.
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Yeah, those Comanches are pieces of ****.

Me + full fuel still leaves me with another 500lbs of payload.
 
You just have to do a little bit of math and make some tradeoffs. My SR22TN is officially a five seater but with all the options it is a heavy bird and the payload is just enough for me and my girlfriend with full fuel.

But I like the flexibility. I can take 2 couples and fly for 2.5 hrs + reserves or I can top off the tanks with just GF and I and nonstop from Austin to Columbus like yesterday.
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98% of my flying I can fill the tanks full and don't worry about it. Now when the wife comes with, I calculate fuel down to the 1/4 gallon, and always round down instead of up.
 
I almost never fill my fuel tanks. I dispense what I need for the flight plus 45-60 minutes reserves. That doesn't vary whether I have a big load or I'm just going solo. Airplane performance is all about weight and balance. Lighter is always better.
 
JB1842 said:
98% of my flying I can fill the tanks full and don't worry about it. Now when the wife comes with, I calculate fuel down to the 1/4 gallon, and always round down instead of up.
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To paraphrase, you carry around hundreds of lbs of ballast and dont have to worry about it? Why lug around 5 hours fuel for a 90 min flight ? Shedding weight is the best performance mod you can do.
 
JHW said:
To paraphrase, you carry around hundreds of lbs of ballast and dont have to worry about it? Why lug around 5 hours fuel for a 90 min flight ? Shedding weight is the best performance mod you can do.
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I own a 150. I don't have 5 hours of fuel to begin with, or hundreds of pounds of ballast to worry about. Could I do better performance wise by not having extra fuel, yes, but I don't worry about it too much unless I'm in a high DA situation, or am using a shorter runway than I usually do, or a combination of the 2. I like knowing that if I want to extend my flight longer, I can, because I already have the extra fuel on board.
 
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JHW said:
To paraphrase, you carry around hundreds of lbs of ballast and dont have to worry about it? Why lug around 5 hours fuel for a 90 min flight ? Shedding weight is the best performance mod you can do.
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Well, I once had to divert 2 hours beyond my destination on an IFR flight. I'm glad I didn't take "just enough" fuel that time.
 
Our group shares a 182RG. Our policy is to fill it to the tabs for the next guy. In that plane, that is still 5-6 hours endurance. If I'm taking the whole family - there are times when I need the extra payload and I will pull fuel out. I have 2, 6 gallon fuel tanks and a hand siphon pump that I use to get the fuel out of the tanks. The fuel tanks do not get used for anything other than AVGas. When I return from my trip - I put the fuel back in the tanks before I call the gas truck.

This gives me over 100 lbs more payload - and still have enough fuel for 3.5 hour flights with reserves.
 
Most of my flying is solo and LONG XC. I fill up most times. Family is three of us total, and one doesn't fly in the Tiger except locally. As far as hauling extra weight ... I do as it seems to calm the desert thermal bounces down and helps a TON if winds are 20G30 direct crosswind.
 
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