flying with fuel in only one tank

[ArtVandelay]

Ok, I think they took that out for litigation purposes

[itsmekw]

I flew my M20C from Ft. Lauderdale, FL to Punta Gorda, FL on one tank. I was having them re-sealed and they found some damage inside one of the tanks. Since they had already removed some of the old sealant I could not put any fuel in that side. After they re-sealed the other side I flew it to an MSC to have the repair work done. Really no issues with flying as far as keeping the wings level, but it was as bit of a concern knowing that if I did have an issue with fuel or flow from the one tank I did not have the other side to use.

[ryoder]

My tanks were leaking, especially the right tank when full. If it was less than half full it barely leaked at all. If it was full it would leak eight gallons out in about five days. Until I lined up a repair I flew with ten gallons in that tank and full in the left tank. That worked for me. Now I have them both resealed.

[cnoe]

The imbalance is no issue. Sometimes the leak will occur until the tank drops to a certain level, then it stops leaking. That was the case in my previous plane (E).

 

After patches by an MSC failed I put 5 gallons usable in the leaky tank (for emergencies), filled up the good side then flew it 900 nm to WetWingologist in Ft. Lauderdale for a reseal.

 

I had to stop for fuel (in the one tank) twice but had an otherwise smooth trip.

 

I'd be reluctant to fly much with a substantial leak, or one that penetrates the cabin, but minor leaks outboard aren't a huge deal. IMO of course.

 

Cnoe

[rocketman]

I recently purposely flew my rocket only from the right tank for calibration purposes until fuel depletion on that side. What happened next was uneventful and expected but the feeling will live forever. While expecting the engine to quit, guess what - it did! Of course I switched to the left tank and it took about a second for the engine to restart. That was one of the longest 1 second of my flying since 1986. A feeling I will never forget. And won't again. The rest of the flight was like flying over the ocean, hearing sounds like the engine starting to sputter again. 

 

Also, I also recognized that on running the tank dry, I forgo another brilliant safety feature of airplanes, a second fuel source if one of them gets fouled or plugged. 

 

So, if you need to have an empty tank for what ever purpose, drain the fuel from that tank on the ground, not in the air. 

[FloridaMan]

I do it all the time. On long trips to ensure that I'm burning fuel as expected and will have adequate reserves, I run one tank for a full 3 hours before switching. Sometimes the engine sputters on me when I switch after that much time. 

[carusoam]

Having a blocked tank vent (NJ mud dauber) cured my desire of running out one tank...

Best regards,

-a-

[Lood]

I've flown my F to its annual on one tank, after I've stripped the other one clean for a reseal. So there was no way I could put fuel in it. I did notice a slight imbalance, but it wasn't a problem.

[bumper]

Based on what?

 

You need three things for a fire: fuel, air, and ignition source. With a leak you have plenty of fuel and air. There are many spark sources on an airplane.

 

In chemical process safety we had a rule that we never relied on absence of an ignition source. If you have fuel and air you have to assume that it WILL find an ignition source.

 

If unsure, and you need a handy ignition source, one could always duct tape a Bic lighter to the wing trailing edge, tie a cord to the lighter button, lead it back to the cockpit and you should be good to go  . . . . insert suitable "Whoomph!" noise here. :c)

 

If the leak is that bad, I'd just go on the other tank, assuming adequate reserves.

[chrisk]

I recently purposely flew my rocket only from the right tank for calibration purposes until fuel depletion on that side. What happened next was uneventful and expected but the feeling will live forever. While expecting the engine to quit, guess what - it did! Of course I switched to the left tank and it took about a second for the engine to restart. That was one of the longest 1 second of my flying since 1986. A feeling I will never forget. And won't again. The rest of the flight was like flying over the ocean, hearing sounds like the engine starting to sputter again. 

 

Also, I also recognized that on running the tank dry, I forgo another brilliant safety feature of airplanes, a second fuel source if one of them gets fouled or plugged. 

 

So, if you need to have an empty tank for what ever purpose, drain the fuel from that tank on the ground, not in the air. 

 

How high were you when you ran your tank dry?   I've done it once, and I was at 12,000 ft.  It was a non issue.  I would be more concerned if I was at FL 200, as the engine might be hard to restart in the thin air. --Or at least the manual has words that suggest going lower for a restart if there is a problem. 

 

Also, years ago I had an old crappy vehicle with two fuel tanks.  One of the fuel gauges didn't work, so I frequently ran the tank dry.   When the engine would quite producing power, I'd throw the switch and it would start right back up in a few seconds.  My one experience of running the tank dry on my Mooney was the same.  It's just like you pulled the throttle back and you feel a bit of a slow down.  Switch the tank, and then it just speeds up again.

[rocketman]

They usually do restart back up but if your not used to doing it, its a very sinking feeling.

[chrisk]

They usually do restart back up but if your not used to doing it, its a very sinking feeling.

Agreed, when I did it last, I got a glare from my wife.

[FloridaMan]

Having a blocked tank vent (NJ mud dauber) cured my desire of running out one tank...

Best regards,

-a-

 

I'll add that my SOP is to change after as close to three hours as possible, within gliding range of an airport. So, if I'm at 9000 ft and over an airport with 2:45 on the clock and the next airport is 15 minutes away, I'll go ahead and switch. I plan my legs to 5 hours max with an hour of reserve. I figure if the climb-out tank gets 3 hours from takeoff with the additional richness of the climb-out and ground ops that weren't included that I'll have two hours on the other tank with an hour of reserve. I may tighten up reserves a little more once I get the totalizer installed next month. 

[jetdriven]

My first flight on our plane after we got it was on one tank. The fuel at our home airport was 2$ a gallon higher than a place 20 miles south and it only had 12 gallons onboard. I drained it from the right and put it in the left, then flew it to lbx to refuel. I added 2 gallons at a time and marked the card that came with the universal fuel hawk. I figured the reduction in safety that one flight due to a single tank with fuel was more than offset by the hundreds of flights we took later in which we knew the fuel quantity on board to within 2 gallons.

[chrisk]

My first flight on our plane after we got it was on one tank. The fuel at our home airport was 2$ a gallon higher than a place 20 miles south and it only had 12 gallons onboard. I drained it from the right and put it in the left, then flew it to lbx to refuel. I added 2 gallons at a time and marked the card that came with the universal fuel hawk. I figured the reduction in safety that one flight due to a single tank with fuel was more than offset by the hundreds of flights we took later in which we knew the fuel quantity on board to within 2 gallons.

So how did you drain the fuel? Was it with the strainer?

[mike_elliott]

Having a blocked tank vent (NJ mud dauber) cured my desire of running out one tank...

Best regards,

-a-

A piece of safety wire in the tank vent really discourages mud daubers, and it wont fall out. 

[jlunseth]

The plane is not going to tip over if you fly with one empty tank. 

 

I would not rely on not getting to the LEL however.  The tanks leak into the wing, and the fuel flows to the wing root, which is inside the cabin.  It usually pools up there because of the longitudinal structural members it encounters.  If you take up the floorboards on an aircraft that has had leakage, you will see a nice blue area there, from the dye in the fuel. 

[Hedge]

That's assuming the fuel is leaking directly out of the tank and away from the plane.  Any fuel that leaks into a wing cavity or the belly has the potential to reach the LEL. 

very true!

[Hedge]

Where in the manual does it say that? I can't find it the J manual.

It says it in my 66E manual.

[Hank]

Says it in my 70 C manual, too. Take off on one tanks fly for an hour. Switch tanks, run the second tank dry. Switch back to first tank, you now have the timed endurance of the second tank less an hour. I'll paste it later, don't have it on my tablet.

Personally, I switch tanks every hour. Each side is good for 2-1/2+.

[ryoder]

My C manual says the same. I don't do that. I burn 7 per hour max and fly with 22 gallons or so in each tank and land with a bunch of gas left over. I don't want to run a tank dry.

[N601RX]

Rather than switch tanks ever 1/2 hr or hr, I've started switching every 10 gallons per the fuel flow. It makes it easy to keep up with how much is remaining in each tank and I don't have to account for how much used on taxi, climbout or cruise.