Graduated Fuel Dipstick. Fuel tank size

[garyfrick]

I recently drained my tanks and did 2 things answered the question as to how much fuel is in the tanks. There's a difference between Europe and the US and Mark Gregor was spot on 16 gallons per tank to the drop. Mark is sending me a calibrated fuel gauge but in the interim I used a sportys universal 11 inch guage and if any one is interested I be happy to give you the number. One thing I should have done was compare the amount on the fuel guages in the cabin but I can do that later. They also sell a slip on stop for the guage so it doesn't end up in your tank. Hopefully this helps

[Flocker]

I recently went through the same exercise. I came up with 16 per side as well. I calibrated the dipstick and compared it to the gauges as I refilled the tanks. The fuel gauges are spot on. I should mention that my fuel gauges are displayed on the G3X. (No analog gauges with the iS)

[jetcat3]

Thanks for doing that y'all. Of that 32 gallons, how much would y'all estimate is useable?

[Flocker]

From my POH:

[Cluemeister]

So 27.4 - 1.1?

That seems odd. Where did the other 3.6 gallons go?

[garyfrick]

In regards to jetcat3's question. I think it's safe to assume 30 gallons are usable and at a 5000 rpm cruise and a 1 hour reserve at approximately 5 gallons/ Hr you'd have about a 5 hour range on the 25 left. I flew with Patrick back from Mankato the outside Ana log Guages read empty and we were still going and we put 29.4 gallons in the tanks. I would never do that again. Even Rotax says you can run a 914TC all day at 5500, that puts it in the caution range on the manifold pressure and that, for me, is a good compromise in reasonable cruising speed and sparing the engine. I've always heard,"you take care of the engine and it'll take care of you".

[garyfrick]

Cluemeister's mention of 27.4 gallons deals with Tecnam's wish to keep the usable load as high as possible. If you've got enough power this is less of an issue and that's what sold me on the 914TC

[Glenn]

Aug 6, 2016 20:28:49 GMT jetcat3 said:

Thanks for doing that y'all. Of that 32 gallons, how much would y'all estimate is useable?

I was very curious about this also.  Fuel gauges are notoriously inaccurate.  If you're curious and decide to drain your tanks to see how much the tanks will hold,
I suggest not using the drain under the wing.  Using the gascolator will give a more accurate "estimation" of useable fuel.  

Glenn

[MarkGregor]

In addition to what Glen said above it can depend on the flight phase as to how much fuel is usable. For example in the pattern the fuel may move away from the tank port due to possible G force and bank angle of the airplane.
With that said I have burned 16+ gallons per side in strait and level flight in several different P2008s. Of course I make sure the tank is completely topped off first.


When I travel across the Country many times I try to maximize legs and will burn nearly all the fuel out of one tank so in the landing phase I dont end up with a small amount of fuel in both tanks.  I much prefer to have 5 gallons in on side than 2.5 in both.

Mark

[Glenn]

Flying until one tank is dry so as to not split the remaining fuel between 2 tanks is standard practice for some ferry pilots with Lycomings and Continentals.  I wouldn't want to do that in my Tecnam because if I understand the gearbox correctly, the prop will stop and I'd have to rely on the battery to restart the engine.  That doesn't give me a warm fuzzy.  My experience is the same as Mark's.  I've added 16 gallons to my tanks but I was not maneuvering.  I was flying wings level.  So I asked Shannon to explain this and his answer gave me a big laugh.  "Oh, Tecnam considers the tank full when it's about 2 inches from the top."  The Italians don't know what full means?  Really?  So my guess is we have the same size tanks that the European models.

Hey Mark, do you think Tecnam sends out all P2008 models with the same fuel tanks?

Glenn

[MarkGregor]

I do not believe the tank size is different between between any of the P2008 models

The know both the 912 and 914 Rotax engine will restart without using the starter at reasonable cruise speeds.
I assume at some lower airspeed it will not but don't know where that is.

Mark

[buzz]

A couple of comments.

1. Was looking at the POH for the 2008 JC model which I think is the European version. It lists fuel capacity as 16.38 per tank/32.76 total/32 usable. I think this goes along with the idea others have spoken about. That being that our tanks actually hold 16 when full to the brim. And that the US version has been de-rated (so to speak) to 14.7 to gain back a few pounds for the useful load. And as I stated in a previous post when I was flying across the country when my tanks were full to the brim my Skyview showed 16 gals. This was backed up by tracking our fuel use. I don't know why the unusable fuel is 1.1 per tank in the US and .38 in the JC.

2. About wind milling to restart an engine. Check out You Tube "Remos GX engine shutdown and restart" Good video on test about restarting a 912 with 3 blade prop. I know it's a different plane and prop but still good info.

3. I intend to be very conservative with my fuel. So many have run their planes out of fuel. I don't want to be that guy.

Buzz

[Glenn]

That's an interesting youtube video.  Strange that a viewer's comments seemed to indicate he didn't think it was a 912.  I'm not a Remos expert but all the Remos I've flown all had a 912.

Glenn

[geobuff]

Y'all scare me talking about burning 30 gallons before you land. I don't care how big the tanks are, when you are on a cross country and get to 1/4 fuel on each side, drop down and fill up. My rule is fly 4 hours and fill up. You need a break by then anyway. The most I have ever put in the tank is 22 gallons. I never have to worry about running out of gas, starting an engine after fuel exhaustion on one side, or about minimum fuel to an alternate airport. Hey just kidding. Go for it. I just am not that brave. Apparently I don't function well under stress, and I think running out of gas is classified as stressful. Yes, when I am flying circles around my home airport, I will go less than 1/4 tank.........
Roger

[Glenn]

Geobuff,

Whoa there!  Sir, I respectfully submit that you've misread or misunderstood!  I don't want to test my gliders skills an more than you do.  I've never burned 30 gallons in my P2008 (and I seriously doubt Mark has either) but I have burned 16 from one side.  When I did it I was in severe VFR at 9500 MSL and when I switched to the other tank and it had 7 gallons remaining.  When I landed I added 16.1 and 10.4 gallons.  It was a bit wing heavy on one side but no big deal.  In my 22,000 hours I have experienced many fuel gauges that were far from being accurate.  
New planes are an unknown.  It's handy at times to know exactly how much fuel is useable.  

Glenn