PIREP: O&N Additional 10 gallon Fuel Bladders

[Oscar Avalle]

Given that I am currently flying in an area where Avgas is only avaiblable at one aiport in the country (!) sometimes I have to strech my reserves and that made me feel a little bid unconfortable. So I decided to add 10 gallons to my 52 gallons in my M 20 C. It seems to me that if you have bladders, the only option available is O&N. They sell you a kit of two 5 gallon bladders with everything you need to do the upgrade. The process is straight forward and relatively easy to do. Now I have 62 gallons avaiblable which makes me feel much better...

 

Oscar

[Oscar Avalle]

Cool, you are indeed right!

[Bob_Belville]

I have O&N bladders from 1997 in my '66E but I do not believe I can get the 27+ per side as advertised. When we installed the JPI 930 six months ago the shop had to carefully fill the tanks as they verified gauge readings. They started dead empty having removed and replace the floats but could not get quite to 26 per side. I'm talking real world, ignoring fuel temp and not rocking wings etc. (OTOH, I think Dr. Bill has verified that he can get 54 in his plane with brand new O&N bladders.) Of course this ought to be academic, no one would ever play it that close. 

[Oscar Avalle]

accounting for the 2 gallons of unusuable fuel i was able to get 32 gallons into each tank.

[Bob_Belville]

Jim, one factor that Bill may chime in on, there are 2 styles of caps, O&N calls them flush and raised. I have the flush, Bill has the raised, I think. But my STC with the flush caps lists 54 gal. (The shop had to scale 0-27 per side even though they could not get 27.) One issue I recall was that the unusable was specs in pounds but the value looked like gals were intended. I'm going by memory, if anyone cares I'll check my AFM which in the the plane.

[Marauder]

Jim, one factor that Bill may chime in on, there are 2 styles of caps, O&N calls them flush and raised. I have the flush, Bill has the raised, I think. But my STC with the flush caps lists 54 gal. (The shop had to scale 0-27 per side even though they could not get 27.) One issue I recall was that the unusable was specs in pounds but the value looked like gals were intended. I'm going by memory, if anyone cares I'll check my AFM which in the the plane.

You got me thinking Bob. My tanks hold 27.4 per side confirmed by the fuel gauge markings. But is that usable?

If it weren't raining so hard here, I would go get my POH and see what the supplement says.

[Marauder]

Oh, BTW, mine were installed in 1992. So I have the flush caps.

[Bob_Belville]

Yeah actually mine are supposed to be 27.4 x 2 as well with flush caps. My logs and FM are in the hanger. I'll go through the info on unusable before and after the bladder convert. 

 

Oscar, did your upgrade include adding an outboard sensor? If not I suppose your gauge read full for the first 10 gal or more on each side.

[Marauder]

From the O&N site:

The NEW 64-GALLON KIT consists of eight bladders, four in each of the wet-wing bays. Until now, M20F and M20J owners sacrificed 9.2 gallons of useable fuel in order to install the O&N bladder system.

So, if my math is correct, I have 54.8 usable. Add in the 9.2 from above, then you have 64 usable. So they need to be able to hold a bit more, right?

[Bob_Belville]

http://www.onaircraft.com/products-services/mooney-bladders/

[1964-M20E]

Mine has the 54.8 gallons marked on the wings 27.4 each. I have not yet run a tank dry to see how much it really takes. Maybe on my next flight to FL I'll try it just to see.

[DrBill]

Mine are new (2012), 27.4 per side, verified and again with PATIENCE. I think it takes about 20 mins to get the last gal or 2 in it.  I have the raised caps (see my galllery).  The nice thing is that they have locks.

It was all pretty much usable in level flight.

Bill

[jetdriven]

Ours says 54.7 gallons usable but it holds exactly that, with no unusable fuel.  And that is only when you let the fuel settle 5 mins and add the additional 3/4 gallon per side.

[Marauder]

Ours says 54.7 gallons usable but it holds exactly that, with no unusable fuel. And that is only when you let the fuel settle 5 mins and add the additional 3/4 gallon per side.

I have never run mine dry in the 21 years I have owned them or I would know for sure. I thought the bladder interconnects would have been slightly above the bottom of the bladder and resulted in a bit of unusable fuel. Guess not.

[N601RX]

There is a pretty large sump area under the pickup.  I would have thought that it would take at least a gallon or more to cover the pickup.

[rbridges]

62 gallons at 10 gallons/hr.  you can cover a lot of real estate between fill ups.

[Bob_Belville]

And @ 8.6 gph you can out fly your personal bladder.

[Marauder]

And @ 8.6 gph you can out fly your personal bladder.

 

Not Bennett and I in our Depends...

[Bob_Belville]

Not Bennett and I in our Depends...

I'd have to break out the old Prestone antifreeze jug. Not sure how Nancy will cope.

[Mooneylooney]

I have the 64 gallon kit with the flush caps and have ran my left tank dry on multiple occasions. When I return home, she takes 32 gallons, no waiting. I absolutely love the upgrade. The extra ten gallons makes all the difference. I have owned my plane for 11 years and have installed many modifications, but the JPI 830 and the bladders are by far the best two mods (well maybe #2 and 3 after the Aera 796!). The peace of mind of knowing how much fuel you have on board (down to the tenth of a gallon) is priceless...