Tip tanks, return fuel, and transfer pumps.
Tip tanks add range and add steps. Whether yours feed the engine directly or transfer into the mains, SkyTimer follows where the fuel goes as you record each change, and reminds you of the next step.
Two kinds of tip tank, two different fuel paths
Some tip tanks feed the engine directly through the fuel selector. Others never feed the engine: electric pumps move their fuel into the main tanks. And on some fuel-injected engines, fuel the engine doesn’t use goes back to a main tank. If your fuel log ignores that, your estimates drift and a main can fill up while you’re feeding from a tip.
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Direct-feed tips with fuel return
The selector feeds the engine from either tip, or both. SkyTimer adds the return fuel to the main tank you choose, at the rate you set.
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Transfer tips with pumps
The engine feeds from the selected main while pumps move fuel from each tip into the main on its side.
Reminders for each step of your procedure
Set reminders for the order your POH and supplement give: start on a main, move to the tips, start a transfer once a main has room, stop it before a main overfills.
- Switch on time or fuel used. Move from a main to the tips, or back, on schedule.
- Start a transfer when there’s room. Get a reminder when a main has room for the tip’s fuel.
- Stop a transfer on time. After a set amount, when the tip is down to a set amount, or when the tanks are balanced.
- One tap to record every change. When a reminder has more than one step, make the changes, then tap Complete All Actions to record them all in SkyTimer.
SkyTimer estimates fuel from your starting fuel, fuel flow, time, and the fuel system you configure. It doesn’t measure fuel. Use it alongside your fuel gauges and your POH, never instead of them.
Aircraft types that start with this setup
These types load a complete fuel system: every tank, selector, pump, and reminder, marked TYPICAL until you check each one against your POH and supplement.
- Beechcraft Bonanza 35 with Osborne/GAMI-style tip tanks (direct feed, fuel return to the left main)
- Beechcraft Bonanza 35 with D’Shannon-style tip tanks (transfer pumps)
Different installation? Build it in the aircraft builder, with up to 7 tanks, transfer pumps, and fuel return.
Questions about tip tanks
Something else? Visit Support.
Which tip-tank installations does SkyTimer support?
SkyTimer includes typical setups for a Bonanza 35 with Osborne/GAMI-style tip tanks that feed the engine directly, and with D’Shannon-style tip tanks that transfer fuel with pumps. For other installations, build your system in the aircraft builder with tip tanks, selector positions, transfer pumps, and fuel return.
How does SkyTimer handle return fuel?
You choose which tank receives the return fuel, the rate, and which selector positions return it. While those positions are selected, SkyTimer takes the return fuel from the feeding tank and adds it to the return tank, and stops adding once that tank is full. In the drawing, return fuel shows as a flow from the feeding tank to the return tank.
Can SkyTimer remind me to turn transfer pumps on and off?
Yes. Reminders can start a transfer when a main has room for the fuel, and stop it after a set amount, when the tip is down to a set amount, or when the tanks are balanced.
Are the tip-tank values right for my aircraft?
They’re typical values, marked TYPICAL in the app. Check every tank, selector, pump, and rate against your POH and the supplement for your installation.
More fuel system guides
Try it with your aircraft.
Download SkyTimer, choose your aircraft type, and check the typical values against your POH.