Hetman

Mitsubishi Mu-2:

Both engines feed from a common center tank to which all other fuel is transferred. There are 2 tip tanks and 2 very small wing tanks. Transfer first from tips, then wing.

dera

And give a good tip to the poor lineguy who has to refuel that plane...

esa17

Fueling a LRJET is easy but there is a process. As mentioned there is only one filler point on each side, on the tip.

If fueling using a single point you have to be cautious of an imbalance because it can cause the aircraft to tip. First side fill to a 125gal imbalance. Proceed to the other side and fill to 250gal and then back to the other side for a top off. During the event you’re likely filling the trunk (1200# in a 35) and being mindful of a bubble. If your aircraft is prone to developing a bubble then you can open the cross flow and try to force it out by sending fuel from the full wing into the the with with the bubble. Leave the cap off the bubble side for best results.

You can also taxi or tug the plane in a few circles and it will clear the bubble.

In flight the tips burn down first. After the tips burn down passed 5-600# remaining you can start bringing fuel forward out of the truck. The purpose of this is to verify the function of the jetpumps which use motive flow to move fuel.

Baffles, flapper valves and a yaw damper are used to combat Dutch roll.

CrimsonEclipse

Airplanes with tip tanks vary greatly.

The Lear 25 and 35/36 fuel directly into the tip tanks and use pumps to transfer to the center tank. If you're fueling the "tips only: you can fuel full blast with no kick back. If they need to transfer to the center tank, you have to wait longer to re top the tip tanks. The 36 has a bigger center tank so you may have to wait around longer.

The Westwind I has tip tanks but fuels through fuel inlets on top of the fuselage and flows into the wings and tip tanks. There are also manual valves (little sticks under the wing you pull to manually open) to allow fuel to flow to the tips.
The Westwind II had singlepoint.

MU-2 are just monsters. Tip tanks and inner wing tanks. No fuel imbalance over 50 gallons and getting to the 15 gallon inner tanks was always a PITA due to the limited space between the fuselage and the engine. The even had weird fuel caps.
It was always fun to watch the wing drip as you fueled one side or the other. Especially if you were alone. Also, NEVER place a ladder under the wind or tip tank.

Twin Cessnas were interesting, the tips were the main tanks and the wing tanks were the aux tanks (except the later models with out tip tanks like the 414A and 421C).
The return fuel line from the engine flowed ONLY into the main tank (tips) this means you had to burn from the tips for at LEAST an hour before using aux tanks. If you use the aux first, the return fuel will overflow the main tanks the dump the excess overboard.
Also, some of them had nacelle tanks to add to the complications.

I'm pretty sure that bonanza tip tanks were directly piped to the wing tanks, (not 100% sure on this one)

G-2's also had tip tanks but I'm not sure about the fueling requirements and burn on that one.

Crusoe

>>Also, NEVER place a ladder under the wind or tip tank.<<

I was looking for this comment. Not disappointed.

NEDude

Holy cow yes! Back in my rampie days we had a corporate outfit with a fleet of 4 MU2's. When they called to ask for fuel, the poor line guy who had to make the trip to their hangar would be gone half the day to fill up those four airplanes. Partially fill one tip tank, then partially fill the other, and back and forth a few times to keep them within balance. Then back and forth between the two wing tanks, and then finally wrap yourself around a couple of the prop blades to reach me main center tank. I HATE(!!!!!) that airplane.

A Squared

I think that for the Bonanza, it depends on the specific type of tip tanks. I flew a Bonanza with tip tanks. I believe they were Osborne tanks, but it's been a while and I'm not 100% sure. Anyway they fed directly to the engine. The thing is, on this Bonanza, the fuel return was always to the Left main tank , so you had to burn out of the left main for a while before burning from the tip tanks, or you'd lose fuel overboard. Kind of like the Twin Cessnas in reverse. (Same outfit had 310/320's) I discovered this quirk on my first long flight in this airplane. I was repositioning the airplane from Florida to Alaska, fueled everything up for my first leg, started burning out of the tips once I leveled off in cruise. Every so often, I'd catch a flash of movement out of the corner of my left eye. Could not figure out what I was seeing and was wondering if I was imagining things. Then I started noticing that I had significantly less fuel than I calculated I should have. After I landed (early) for fuel, I notice that there were blue fuel stains on the top of the wing coming from the left main fuel filler. Apparently the overflow fuel would build up pressure and force a periodic spray of fuel past the filler gasket and that was the flash of movement that was catching my eye. Although, looking back I wonder how the main tank was pressurizing ... maybe the vent was plugged with a mud-daubers nest. At any rate, once I modified my fuel management technique to allow room in the left main for the fuel return, I found I could fly a lot further on full tanks of fuel.

There are different manufacturers of Bonanza Tip tanks. You may be right that others transfer to the main tanks. That's the way the locker and nacelle tanks worked in our twin Cessnas.

A Squared

If you'd sent 2 trucks and 2 rampers over, and fueled both sides at once, you could have fueled the fleet in a quarter of the time. Sometimes the whole is greater than the sum of it's parts.

FlyJSH

Throw in wing locker tanks and get close to seven hours endurance... which was good because reading and comprehending the fuel management checklist took almost that long. Seven hours without a relief tube was miserable.

mherrig97

Not sure how it works in a Learjet but the 172 I fly has tip tanks. They do not feed the engine, instead, they just dump into the mains when I turn the pump on. The main must be at least half empty before I can pump, then I have to switch to the other tank because the tank being filled cannot be feeding the engine. I just flip the switch and it fills, takes about 10 minutes to empty the tip tank, 11gal usable each side.