Fuel Management

I don't do it myself but it's not an uncommon practice to run a tank dry on PA28's.

I probably would if I was stretching my fuel reserves that much but that's rare.
 
airguy said:
The only time I've gone from BOTH to single tank-draw in a high wing single was to verify that there was not a problem feeding from either tank, and I most likely needed a bit of rudder trim to get a little closer to "coordinated" in cruise. On a 3-hour cruise leg (which I do a lot of) it's amazing how quickly a fuel imbalance can show up without appearing on the slip/skid ball.
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If you're on autopilot with no yaw damper, a fuel imbalance could show up on the slip/skid indicator, but use of rudder trim will hide that indication. If you're hand-flying, it will show up more obviously by the amount of roll force you need to keep the wings level.

In any event, I've had three close calls with fuel exhaustion (one of which involved landing with 9 minutes of fuel remaining), the last of which was more than 30 years ago. Since then, I've always planned to land with 60 minutes of fuel remaining (30 minutes each side in a 2-tank SE airplane), and if at any point it appears that isn't going to happen, I land short to refuel.
 
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Henning said:
Mine give enough advance notice in the stumble that they rarely actually die off altogether, and then it's on again within a second or two.
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That's what I run into as well, except for when I forget I'm dry tanking, and it all goes quiet. But certainly nowhere near 10 seconds.
 
Sac Arrow said:
I don't do it myself but it's not an uncommon practice to run a tank dry on PA28's.

I probably would if I was stretching my fuel reserves that much but that's rare.
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I do it just to know where my fuel is. When I flew Grand Rapids --> Sarasota non stop, I wanted to know where all my fuel was. No sense in thinking you might have 3 gallons left in each tank, especially if something goes funky and you have to divert. I landed with 3 dry tanks, but 1 hour of fuel left in the one tank where I knew all the fuel was. Of course, this is a PA24, when I had my 28, there was only two tanks, but I still would dry tank one.
 
EdFred said:
I do it just to know where my fuel is. When I flew Grand Rapids --> Sarasota non stop, I wanted to know where all my fuel was. No sense in thinking you might have 3 gallons left in each tank, especially if something goes funky and you have to divert. I landed with 3 dry tanks, but 1 hour of fuel left in the one tank where I knew all the fuel was. Of course, this is a PA24, when I had my 28, there was only two tanks, but I still would dry tank one.
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So is the chance that the engine wont start back up once you add fuel a low probability or what?

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.

Just a little concernced about the restart, all I did was switch tanks and it restarted.... do you ever have to crank it or does the wind do that for you everytime?
 
Jhernandez04 said:
So is the chance that the engine wont start back up once you add fuel a low probability or what?

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.

Just a little concernced about the restart, all I did was switch tanks and it restarted.... do you ever have to crank it or does the wind do that for you everytime?
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If the engine was running fine before the tank ran dry, there is nothing to stop it from running equally well once you reintroduce fuel.

The engine will restart by itself if the prop continues to windmill. If the prop stops, you'll either have to use the starter or dive to sufficient airspeed to cause the prop to windmill.
 
kyleb said:
If the engine was running fine before the tank ran dry, there is nothing to stop it from running equally well once you reintroduce fuel.

The engine will restart by itself if the prop continues to windmill. If the prop stops, you'll either have to use the starter or dive to sufficient airspeed to cause the prop to windmill.
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I enjoy learning stuff that can save my skin! Thanks guys.
 
Jhernandez04 said:
So is the chance that the engine wont start back up once you add fuel a low probability or what?

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.

Just a little concernced about the restart, all I did was switch tanks and it restarted.... do you ever have to crank it or does the wind do that for you everytime?
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If the engine won't start back up, it was most likely going to quit even if there was fuel in the tank.
 
Jhernandez04 said:
So is the chance that the engine wont start back up once you add fuel a low probability or what?

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.

Just a little concernced about the restart, all I did was switch tanks and it restarted.... do you ever have to crank it or does the wind do that for you everytime?
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An engine needs air, fuel, compression, and timed ignition to start and run. If one removes the fuel and the engine shuts down from lack of fuel, then you return fuel to it, why do you think it would not run?
 
You'll be amazed at how quickly you switch the tanks and the engine fires back up, especially if your wife is screaming at you from the back seat! :D
Honestly, it's a matter of seconds to reach down and switch tanks in most airplanes, unless you are asleep when the tank runs dry, the prop won't stop. ;) In twin Cessnas it's pretty common practice to run the aux tanks dry, I just watched the fuel flow gauges when I knew the tank was nearly empty, at the first sign of fuel flow surge, I switched tanks. :D
Jhernandez04 said:
So is the chance that the engine wont start back up once you add fuel a low probability or what?

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.

Just a little concernced about the restart, all I did was switch tanks and it restarted.... do you ever have to crank it or does the wind do that for you everytime?
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I try to never run until dry-out, so I don't have a dog in the fight, but aren't you risking sucking up any trash or sediment?

I know someone will say that's what filters are for, but then you have coated your filter.

How many coatings will it take is the question.
 
Different airplanes require different fuel management procedures. I would start by looking at the POH and any STCs to understand how the fuel system is set up and if there are any limitations on how you use the available fuel.

My early Bonanza has a left and right main and a left and right aux tank. The aux tanks are tied together and only have one position on the selector. All return fuel is returned to the left main tank so you need to start with that tank to create space for the return fuel. I typically burn off an hour of fuel in the left main (which will leave it half full) then switch to the aux tanks and run them to exhaustion. Then on to the right main and finally back to the left main. It is rare that I have the aux tanks full however, because most of my trips are shorter or I need the extra carrying capacity.

The Baron I fly is a little more straightforward, left tanks feed the left engine and right tanks feed the right engine. Both airplanes have limitations on when the aux tanks are used so I typically climb and level off then switch to the aux tanks until they are empty, then switch back to the mains.

I typically have left the SE Cessna fuel selectors in the "Both" position but some have limitations on the use of the "Both" setting above 5,000'. In those cases I'd just switch every 30 minutes or hour.
 
txflyer said:
I try to never run until dry-out, so I don't have a dog in the fight, but aren't you risking sucking up any trash or sediment?

I know someone will say that's what filters are for, but then you have coated your filter.

How many coatings will it take is the question.
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As said before...where is the fuel coming from in the tanks? Not the top. I'll let you figure the rest out.
 
txflyer said:
I try to never run until dry-out, so I don't have a dog in the fight, but aren't you risking sucking up any trash or sediment?

I know someone will say that's what filters are for, but then you have coated your filter.

How many coatings will it take is the question.
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As stated earlier, since you suck of the bottom of the tank, nd the trash in the tank is heavier than the fuel, what trash is there that is of higher risk empty than full?
 
Jhernandez04 said:
So is the chance that the engine wont start back up once you add fuel a low probability or what?
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In most normally aspirated, carbureted piston aircraft engines, yes, it's very low.

Im just scared it wont start again, granted the one time I did it by accident, it started right up but I dont want to take chances that I dont need to.
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Wise choice -- no sense taking risks you don't have to. My feeling is that if you have to run tanks empty to make your destination in a light plane, your destination was too far away to begin with or you made some bad choices along the way.
 
Main tanks (39.5 gallons usable).
Tip tanks (20 per side)
Baggage Compartment (20 gal).

Usually we keep the mains and baggage full and the tips empty. After you get the main down below 1/2 or so you can pull the valve and the baggage gravity feeds in the main.

The Navion is one of the few low wings that doesn't have LEFT-RIGHT on the fuel selector. It's on-off on the stock configuration.

On long X-C's well fill the tips. Fly the mains for about an hour (the return goes to the main when feeding from the tips), turn on the left tip for 5 min, then the right for 5, then engage the cross feed. After burning these down you go back to the procedure for the main / baggage.
 
Ron Levy said:
In most normally aspirated, carbureted piston aircraft engines, yes, it's very low.

Wise choice -- no sense taking risks you don't have to. My feeling is that if you have to run tanks empty to make your destination in a light plane, your destination was too far away to begin with or you made some bad choices along the way.
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Why, if I have 4 tanks , would I want 15 minutes in each tank or 10 minutes in 6 tanks, rather than 60 minutes in one tank? (Comanches have both setups - and I'm pretty certain are still considered a light plane) Especially when you might be flying an approach at your destination and now you're throwing fuel management into flying the approach. Why would I want to add that to the mix when I can easily avoid it? Unless of course landing with over an hour of fuel is a bad choice.
 
Henning said:
As stated earlier, since you suck of the bottom of the tank, nd the trash in the tank is heavier than the fuel, what trash is there that is of higher risk empty than full?
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Got it. Makes sense. :yesnod:
 
I only have two tanks. 32.5 gallons each with 5 unusable in each.

If I'm on a XC of more than three hours I ALWAYS dry tank the left tank because I can pick up almost all of the 5 gallons of unusable when straight and level. That's almost 30 minutes of add'l fuel.

I burn 11 GPH so I can fly for 4.5 hours instead of 4.0 and still land with an hour's reserve.

I have a fuel flow meter and it'll always give me about a minute's warning before the engine starts stumbling. It'll start fluctuating wildly from about 4 to 25 GPH as I start sucking air. The engine doesn't stumble yet because of the gas in the gascolator and carb bowl. I'll wait for the first stumble and then switch.

I'll also rock the wings and then go back to the dry tank about every 15 minutes to make sure no fuel has cross fed and that it is indeed still dry.
 
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When I drain the fuel with the drain knob before the first engine start of the day, I always confirm it closed back up before starting the engine.

Silly point to the experienced maybe, but that's how I was taught and it's stuck with me.
 
My 1967 Mooney POH says to start on one tank for one hour, switch to the second tank for another hour, then go back to the first tank and run it dry. Yes, no big deal all. As soon as you switch to the tank with gas it fires right up. I do this only on flights where I'm stretching the limits of my range. My personal rule is to make sure I have one hour reserve, so I'll use my JPI with fuel flow to make sure I have the required amount on one tank and I'll run the other empty or near empty on a long XC. My JPI is accurate to within 1.2 gallons over 5 hours (it conservatively shows that I have 1.2 gallons less than the actual amount remaining)
 
txflyer said:
When I drain the fuel with the drain knob before the first engine start of the day, I always confirm it closed back up before starting the engine.

Silly point to the experienced maybe, but that's how I was taught and it's stuck with me.
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Not so silly.

It's really easy to leave a drain open on a PA28 if you twist the sample jar while sampling. That could be a really big problem on the gascolator drain.
 
Deakin has strong things to day in favor of running it dry over on Avweb.
I've run mine dry both with the old Gopher carb'd engine and with the IO-550 I have now. Not a problem. It is a bit unnerving to run a tank dry in the middle of a procedure turn (sorry about that Mr. Instructor) but Margy and I have the drill down for running the tank dry.

My only real fun one was when I got the great idea to taxi accross Dulles on the tip tank figuring it would put some fuel in the mains (which it does). WHat I had not accounted for is that at throttle idle my engine pumps a LOT of fuel into the return line. You can drain a tank in 20 minutes where as it takes over an hour in the air. Now I didn't notice anything to wierd on takeoff (there was a crosswind so I didn't note the wing heavy) but he autopilot started doing S-turns across the course. Kicking it off line the plane rolled strong to the left. Oops...no fuel in the right tank.

The only other real fun one was when Margy did her prelanding checks on downwind and switched from LEFT TIP to OFF rather than MAIN. That woke me up (almost as much as the time she smacked me with the water bottle on downwind).
 
Early Bonanza. Start on left(excess fuel returns to the left tank), burn for 90 min. Switch to center aux and run dry. Switch to right and run dry, switch back to left and land. If the flight doesn't require all the fuel, I burn aux in flight, then right, then left. Always take off and land on left unless it's below 10Gal(not likely).
 
EdFred said:
I do it just to know where my fuel is. When I flew Grand Rapids --> Sarasota non stop, I wanted to know where all my fuel was. No sense in thinking you might have 3 gallons left in each tank, especially if something goes funky and you have to divert. I landed with 3 dry tanks, but 1 hour of fuel left in the one tank where I knew all the fuel was. Of course, this is a PA24, when I had my 28, there was only two tanks, but I still would dry tank one.
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I'm not saying it doesn't make sense, especially with four tanks.
 
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