Which fuel tank to select for T.O. and Landings?

Seems like I've heard somewhere along the line, that a super cub with a stock fuel system, should be taken off and landed on the LH tank. I've read the owners manual and didn't see anything. Has anyone else heard this??
Brian

Which Tank.

You heard right. Just do it. Jerry.

Same here... Search for a post on this subject. I did this a while ago.
Seems that the RH header tank is far enough below the carb when you are in high angle situ that there is a possibility that it won't do its part in our gravity feed situation.
Whether it's true or not I know not but it was what I was taught and so far so good.
I normally run off the left tank for a while- say 15 minutes or so- just to get the gas below the point where it won't splash out on a rough strip and make sure it is "good" gas and then switch to the right tank till it is gone or I need to land. My right wing is a bit heavy anyhow so it doesn't bother me none to fly RH tank empty and left almost full.
Scott

Also, the left tank has a forward and aft outlet versus the right tank having only an aft outlet, on most cubs.

Dave.

On my L18c the right tank header is behind the baggage area, so below the carb when tail is down The left tank header is on the bulkhead. I've always been told Left tank Take off and landing. I don't know why they don't both feed into the forward header. I don't have a both option on my fuel selector.
Pete

I've seen a 180hp Super Cub do a max rate take off on the right tank. the flight lasted less than a minute, and ended up with the cub wiping off it's undercarriage, bending the fuselage, and bending the prop.
If you have the stock fuel system, DON'T TAKEOFF ON THE RIGHT HAND TANK!!!

On rebuild, "most" consider a better way to go is to feed from both fore and aft of both tanks and put in a "L/R-both selector with no header tanks, also adding a "low point rear sump".


Tim

Which tank for takeoff

I've always been told that the reason for the left hand tank only on takeoff AND LANDING is because the right hand tank does not have a forward fuel pickup, so can unport in some attitudes, and because the right hand header is below the carb in a nose up attitude. So, either in a descent or climb, the right hand tank is not a good choice. I believe that some owner's manuals have an admonition to operate on left hand tank except for cruise flight, which is a little obscure.

When they install a Cessna fuel selector, they generally remove the header tanks. You then run on "both" tanks for takeoff and landing, just like in a Cessna. Personally, I never liked that system in a Cessna, and could never figure out why the heck you'd put it in a Cub. I like the option of completely separated tanks, myself.

That said, when you get in an unfamiliar Cub, you'd best understand that there is no such thing as a "standard" cub anymore, and you'd best fully understand what sort of modifications and systems you are dealing with.

I know of at least one guy who died in a Cub with a Cessna fuel selector, with the selector on left tank, and no gas in that tank. Right tank had gas. Ran out of gas after takeoff, and stalled, spun, and died. A bad scene for all.

Know what sort of airplane you are flying. Some of these changes can kill you if you don't undertstand them, and manage them appropriately.

Mike Vivion

Fuel Selector

To answer the question about what tank to use on a stock PA-18. "Take offs and landings on the left tank, cruise on the right". That has always been the rule of thumb and has been practiced because the way the stock fuel system is plumbed. As far as the "both tank" set up. I personally like it. Had one of each (two planes) last year and during the rebuild of my PA-18 switched it over to the "both" set up as well. The STC requires a lable that states "both on take off and landing". If you follw this simple procedure you will never have any problems as the guy in the previous post did. Sorry to say, but that was blatent pilot error!!! It is a safer system if operated correctly.

Mike Vivion wrote:

I know of at least one guy who died in a Cub with a Cessna fuel selector, with the selector on left tank, and no gas in that tank. Right tank had gas. Ran out of gas after takeoff, and stalled, spun, and died. A bad scene for all.

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If you don't have gas in the left tank on a stock system the engine will quit as well!!! Crash

I always select the one with the most gas. I did land in Galena, Alaska one time and I honestly couldn't tell which one that was. They both read empty. I guess from now on I will select the left tank and cross my fingers. I do remember that I landed in Galena with 2 gals left in the tanks. I ran into an unexpected 40knot headwind. That will ruin your day.

Torch

Dang I guess the saying ignorance is bliss must apply here. I've never paid attention to what tank I'm on as long as it has fuel in it. Maybe I haven't had the need to climb as steep after takeoff as some of you. Guess I'll go put a quarter tank of gas in my right tank and see how long it will last as steep as I can get it.

Tanks

My previous post reference the Cessna fuel selector installation didn't mean to imply that it's a bad installation, but rather, as I noted, no matter what system you are operating, be darn sure you understand which system it is, and it's operating limitations and recommendations.

By the way, the system with the Cessna fuel selector also provides slightly less fuel, since the header tanks are no longer installed, so the fuel normally available from them isn't there any more.

I hope nobody works that close to the edge routinely, but as I noted, understand what system you are flying, and don't just get in another Cub and assume they are all the same,

Mike V

Having flown the "headered stock cub" arrangement for thousands of hours in at least a half a dozen differnent cubs over the years I can attest to all are a little different? It was and is still common to fill the tanks run the right one out and then run the left one till the 'time is up'. That being said ya better know your plane well when doing so. I have admittably had a few close calls when I 'forgot to switch tanks, "tired", almost home, the hunter won't shut up, or trying to stretch it? the closest I came to "buying it" was when I took my wife for a ride and on the way back home the Right tank ran dry, the engine caughed and she grabbed my shoulder in terror! the problem was that in her excitement she got infront of the shoulder harness and I couldn't move forward enough to reach the fuel selector and she was screaming in the headset so loud that I couldn't get her to stop! the engine quit and we were within 50ft of the trees when finally I struggled free of her grasp and was able to swith to the left tank!

Moral of the story, "know your fuel system, and also know your wife"!

I must say that I think that the stock system is just fine, and it does give a pilot a good way of know just what is left to fly on? We used to when the right tank ran dry, fly to the fuel cache on the left and then put the 5 or 10 in the right knowing again just how far we could go. This proceedure allowed us to manage fuel and not overload the plane with fuel, allowing us to carry more "pay" in/out of the camps safely?

I know use a JPI-FS450 fuel flow scanner connected to my handheld GPS and on the most recent trip to Alaska, I was able to manage the fuel to within 1-2 tenths of a gallon with out ever running a tank dry! More then anything this accuracy was piece of mind (especially when taking off without the ability to "see" fuel in the site guages at a 3 point attitude.

Thanks Mike V. for your comments and as well to Crash and others that use both the "original and the headerless" systems in the Cub!

Fly safe,

Tim

Fuel Tank Selection

I have been told the left tank is the primary tank on a cub due to the fuel line lengths. I was never told this during any of my instruction. I have been taking off on left or right tank since I have owened my cub with no troubles. I have both header tanks that have 2 quarts capacity each, there designed is to supply fuel during takeoffs. When I rebuild my cub I will remove the header tanks and install the larger fuel lines my thinking is if I ever wreck my plane I don't want a ruptured fuel tank between my legs.

Cub_Driver

Eat Drink and be Merry

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T.J.

I was told when removing the header tank the diameter of the fuel line must be increased per the STC. I could be wrong being I was told this and have never read the STC. I beleive you can change the fuel selector valve giving you the option of running off both tanks at the same time. It would seem to me supplying the fuel strainer with a larger diameter fuel line would give you some of the same advantages of the header tank due to the higher volume of the line and the ability of the line to pass more fuel at the same head pressure. Then can feed your strainer with both tanks and never worry about starving your engine again on takeoff. Now this is just me thinking I have not done this conversion yet, but its my story and I'm sticking to it.

Cub_Driver

While were on the subject of left tank , right tank in a stock fuel system. Is there a better fuel selecter swtich than the original? You know they get sticky after a while, and "feeling" the detent can be hard to locate. Not much fun when switching tanks in turburlent air. If it weren't for the indicator on the handle and good placarding, you can miss the sweet spot. I know we grease em at annual, but is there something better to use??

jk , there was a thread about taking the selector apart, cleaning and using Fuel Lube rather than grease. A year ago mine was so bad I thought it was junk for sure...tried this and it got sooo smooth I thought something was wrong? Works really well! Been that way scince!

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The later model super cubs had a fuel selector that had a nylon/plastic like center (the portion of the selector that rotates). I don't know what year they used these, but I just changed my cub over a few months back. Works great, nice and smooth and can feel the detents. We happened to have one in stock. Was a piper part number and approved for PA-18's. Maybe someone else knows about them. If memory serves me on the parts tag it said "direct replacement".
Brian

Fuel Selector

Both Penn Yan and Cubcrafters 180hp conversions call for 3/8" fuel lines and require the fuel selector to be drilled out for the "BOTH" position and cross over vent line between the tanks. Penn Yan does not require removal of the header tanks for the conversion but I think Cubcrafters requires their fuel system that removes the header tanks. Crash

jk said:

While were on the subject of left tank , right tank in a stock fuel system. Is there a better fuel selecter swtich than the original? You know they get sticky after a while, and "feeling" the detent can be hard to locate. Not much fun when switching tanks in turburlent air. If it weren't for the indicator on the handle and good placarding, you can miss the sweet spot. I know we grease em at annual, but is there something better to use??

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Univair sells one that is great. Kinda spendy but I put one in over 10 years ago and have never had a problem with it.

Finally got my right fuel tank low enough to test. Ball barely visible in guage while sitting on ground. After I took off, i climed at 40 mph indicated at full throttle for 3000 ft and never got a hint of a lack of fuel. This is on a 160 hp Super Cub. Maybe this idea came about because of the 180 hp.
Best recommendation is to try your own cub out to see.I'm not afraid of taking off in mine on the right tank.
An extended glide on the right tank with low fuel might be another story---wait a minute, I did that after my test--oops!!

Can't take off on the right tank..another wives tale, just like, can't turn or glide on the right tank. This has been discussed and dispelled in other threads.

If a Super Cub will only run on the left (front) header in a steep climb, how the heck can you do a steep climb with the headerless system? By that theory, the headerless Cub should quit running as soon as you put the nose up.

All this crap is based on the old wives tales and B.S., not how the aircraft operates in the real world.

It's not complicated. Know how the system you have operates. Keep enough gas in it so it operates properly. If you are low to the ground and low on fuel with ANY system, don't do anything stupid.

SuperCub MD said:

. If you are low to the ground and low on fuel with ANY system, don't do anything stupid.

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Gotta hand it to ya Boz........K.I.S.S. !

Out of gas.

Hi Mark. Ya have to be careful painting everything with the same brush. There are always exceptions. I have a stock S.C. fuel system. I can climb all day at 28mph. But if I slow it down to 26mph it runs out of gas and quits just like you threw the mag switch. That's on the left tank. The right is just out of the question. A long steep descent on the right tank is a poor choice also. It will port with 2 or 3 gallons left. I always empty my right take first while still at altitude and positive AOA. Take Care. Jerry.

Opps.

Mark. I forgot to attempt to answer your question on the headerless systems. All of the CC conversions that I have seen have the cute little bug/rain catchers on the fuel caps to make pressure in the tanks so the system will work. And they require both for takeoff. Effectively creating twice the pressure at the fuel gascolator. It sort of complicates a simple system. Jerry.

Jerry, I thought I read somewhere that you don't have a rear header installed? Putting it in wouldn't hurt, but at the angles your Cub probably runs at those speeds (guessing), you may need a header up by the spinner to keep positive head pressure. Maybe I always have what some concider "too much" gas, but I have never unported a tank unless I was trying to do it, to see what flight conditions the plane needs to be in to make it quit, so I can avoid those situations. I try to avoid cutting a trip right down to where I actually NEED those last few gallons, I'm just not that lucky.

Have you ever tried the bug/rain/wing cover catching caps on your Cub to keep head pressure?

I'd just hate for some poor shmo to try taking off on the left tank, with nothing but fumes in the left tank, even if he has lots of gas in the right tank, because he heard or read somewhere that is HAS to be done that way... I did paint with to wide a brush, there will be exeptions, I also said to know how your system operates. Saying that no Cub should ever take off on the right tank is painting a little wide too.

I've heard rumors your coming this way Jerry...it should be fun.

Gas

Hi Mark. Boy are you fast, you must live on top of your computer. You are correct, I dont have a right header at this time. I have tried it with and without the header, and it will run longer with the header, but will still un-port at the same deck angle due to the pickup position. I have never tried the bug/rain catchers. I figured I would have to remote the pickups to a place in the propwash and run it up for 5 minutes or so to pressurize the tank so I could do a take-off. I don't know if it has ever been tested or the feds just thought it was a good idea. I notice most of them are real tall. Some J-3's won't transfer (drain) fuel from the wing to nose unless they have a tall pickup because of the low pressure where the wing tank gas cap is. I agree with you whole heartedly about using the right if it has more gas. Keep your attitudes in reason and there should be no problem. I prefer to run the right dry as a method of accuracy. It's empty, period. What I have is in the left, and that gage is very accurate. No guessing, in case you find yourself in a bad situation. I always enjoy your comments. Jerry.

I've always tried to get the left tank low first in case a gunner gets careless and puts a hole in the tank.although, it probably wouldn't matter by then anyway. Now with the Atlee 30 gal tank in the left wing, I try to get it low for weight purposes. It is terribly inaccurate after a half tank is gone so I dont trust the guage much. And I have a hard time taking off on a tank that isn't registering even though I "think" there is more than an hour in it. I've seen gas mysteriously dissappear from tanks before for various reasons.