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Time to restart after running tank dry
On my Caribbean trip next December, I want to maximize the useable fuel in the aux tanks, but as I will most of the time be flying over water I don't want either my wife or myself to faint during the procedure
I must confess that I am not convinced that I will have the gust to do it!
N9359P
Andres Darvasi- Posts: 75
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- Location: Mexico City, Mexico
Re: Time to restart after running tank dry
- kenhill
- ICS member
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- Location: Alaska
Re: Time to restart after running tank dry
If you have a fuel totalizer, like a Shadin or a JPI, you can get very close to the bottom by noting the fuel left each time you switch tanks. You can get almost as close with timing.
If you are going to go to the ends of endurance, then I recommend that you find out exactly how much fuel each tank holds by running it dry and then filling it up. You may be surprised at how much the tank holds, or not. Don't trust the book numbers. Remember, the mains need to be filled all the way to the very top of the collar or they are not full.
Kristin Winter- ICS member
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- Location: Northern California
Re: Time to restart after running tank dry
I do have a fuel totalizer and I keep close tab of my consumption at every tank switch, even made a little form for this purpose, that gives me the exact amount left in each tank. Also, at the recent annual I had the fuel level sensors overhauled and the gauge is working accurately.
My wife flies with me because she likes de idea of travelling together, she does NOT enjoy flying in small aircraft, so you are right that I should not try anything "strange" with her on board, when i had the T210 we had a couple of times vapor lock issues which made the engine cought for a few seconds, and she REALLY noticed it.
Moreover, I got with the aircraft a perfectly calibrated measuring stick that I use in every pre flight.
The mains are always filled to the collar.
I will follow your advice and measure the real capacity of each tank.
Again, many thanks for your help.
N9359P
Andres Darvasi- Posts: 75
- Joined: Tue Feb 12, 2013 5:58 am
- Location: Mexico City, Mexico
Re: Time to restart after running tank dry
I know you have a few long legs planned on your trip. When is your group heading east and could you give a route?
JIMICS2452- ICS member
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- Location: Pine Shadows Airpark - North Fort Myers, FL
Re: Time to restart after running tank dry
On the Twin the Shadin fuel flow shows rapid and dramatic variability in fuel flow before any engine sound of fuel starvation is heard or felt. So, I enlist whoever is flying right seat to monitor during last 2 gallons by keeping their finger on the edge of the gauge. Like Kristin, I have run the tanks dry hundreds of times - catching the fuel flow variability has allowed many no-engine-sound change tank changes while running tanks dry and it takes away the scary surprise of engine noise change.
That being said, I would go to perhaps 0.5 gallons and change so your wife can ride in comfort - perhaps she would monitor the totalizator for you -just a thought.
Hope this helps.
Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
N3322G- ICS member
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- Location: Fort Worth, Texas area
Re: Time to restart after running tank dry
I will enlist my wife's help in several tasks during this trip so hopefully familiarity will help her relax and enjoy the flights!
N9359P
Andres Darvasi- Posts: 75
- Joined: Tue Feb 12, 2013 5:58 am
- Location: Mexico City, Mexico
Re: Time to restart after running tank dry
Kristin Winter- ICS member
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- Location: Northern California
Re: Time to restart after running tank dry
N9359P
Andres Darvasi- Posts: 75
- Joined: Tue Feb 12, 2013 5:58 am
- Location: Mexico City, Mexico
Re: Time to restart after running tank dry
An additional tip: when filling the tanks, first pull the nose down to collapse the nose strut as much as possible. The more level attitude allows more fuel in the tank because it makes the air bubble at the top of the tank smaller. The late Bill Creech, a past president of ICS, even made a device to jack up the tail when refueling to achieve the same result. His experience was that the additional capacity was as much as a gallon per tank. My experience matches his.
On the aircraft with carburetors, the very first indication of a dry tank is the fuel pressure gauge going nuts. It gives at least 15 seconds warning of the coming silence. I don't know if this applies to fuel injected engines.
Hank
Henry A. Spellman
Hank Spellman- Moderator
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Re: Time to restart after running tank dry
- kenhill
- ICS member
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- Location: Alaska
Re: Time to restart after running tank dry
Kristin Winter- ICS member
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- Location: Northern California
Re: Time to restart after running tank dry
After about a 4 hour leg on an 8 hour day... in the single... we lost power due to fuel starvation -- after the "what the heck?" moment... I quickly switched and it was back on line within less than 10 seconds... my wife still claims it was closer to 30 minutes, ... but the truth is probably somewhere in between.
I think that there is a spec for a certificated airplane that it must start withing "X" seconds after loosing power due to fuel starvation and when a tank has been switched. Perhaps someone knows that number.
Jim Covington
- MULEFLY
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Re: Time to restart after running tank dry
Does she still bring it up and how many years has it been?
Kristin Winter- ICS member
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- Location: Northern California
Re: Time to restart after running tank dry
Perhaps my encoder is slow, but I think I'm still pretty with it!
All the best!
Jim
- MULEFLY
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- Location: Wisconsin
Re: Time to restart after running tank dry
On the fuel flow variation. We use the Shadin fuel computer - perhaps the processor is faster or because it is dedicated to fuel management ... don't know. Perhaps it is where the transducers are located ... not bragging but factually stating we rarely get silence, surging sometimes but not silence on the twin - even when the tip and aux were mis-wired and the dry tank was a 100% surprise, we got surge and yaw but not silence. The predecessor to the Shadin was an Aerosonic fuel computer. We won it around 1976 in an air race from a company in Clearwater FL - not sure if they became Shadin. Just happy it works well for us.
Patricia Jayne (Pat) Keefer ICS 08899
PA-39 #10 Texas
N3322G- ICS member
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- Location: Fort Worth, Texas area