About to install a UAT in my Futura and had a general question for you guys.

I have always installed UATs at 45degrees but it's trickier to install like this. I just wondered how many people simply install them horizontally or vertically? Are there any perceived disadvantages to doing so?

Vote away above and comment away below

Cheers,
Mark

it's vertical in my bobcat with no problems and 45 deg in everything else i've had. Have you seen the new baby bottle version Ali is selling?

Dunc, is it easier to see an air pocket when at 45 degrees than upright? The bubble collects nicely right in the corner that is most visible when at 45deg (if you know what I mean).

Yeah, they're the PST ones - I asked him to get hold of one for me for my Tommy Hawk to avoid the 200 potentially collapsing a non rigid UAT.

Again, this is a 160 install and I've had no issues in any of my installs in the past with this size turbine. I will err on the side of caution with the 200SX Tommy Hawk and go 3/16" bore tygon throughout and rigid UAT.

M

It's easier to see it when it's at 45 deg, the cap kind of hides them when you have it upright. Plus at 45 the bubbles are around the fill and in lines, which has got to be better than having it anywhere near the out for the fuel pump??

Dunc

Yep, agreed. Another 45deg install coming up

Mark,
I've use 'em 30 degrees and horizontal, no problems over 100 flights with either way,
Gary.

its doesnt matter in flight mate.
plane can turn everyway.

it matters only in fueling to take the air out so niple goes to the main tanks must the higher point.


my 2 c

Hi Mark

Heres my opinion. We all know a UAT will work in any orientation because that’s what happens when we fly. The advantage of putting it at 45 is that is purges the air when fuelling. The only other thing to consider is that a vertical half empty UAT will draw air when even a Supersport is at full power so your P-200 has no chance and I guess that restriction in the fuel system will only make this situation worse. A half empty horizontal UAT will not draw air. Of course if you have no air in the UAT there’s no problem.. The big nipple UAT I made really works well especially as none of the fittings, tube or clunk are less that 4mm I.D.

Jason

Kero start turbines are so tolerant of air in the lines, I have got rid of mine and use an Orbit clunk this has a bag and felt filter combined, had not problems with my Elan or Rookie no matter what orientation I put them into, just one opinion and on the vote looks like the only one.

Mike

Mike,

Have you got a link to the clunk?

Also, what do you mean about kero start being tolerant to air in the lines? Not heard this before. I thought air was bad news to any turbine??

M

For your P200 install, get a JMP Accumulator and forget about ANY problems with a header tank failure. You'll never collapse or crack it that's for sure. AND, it has nice mounting lugs machined right into it!

Jeremy, the only thing I don't like about that is that you can't see what's going on inside it which is the first thing I want to be able to see on the ground during tests etc

PMSL, someone else told me that a certain make of turbine were tolerant to air in the fuel lines, right after they had crashed a model, i laughed then too (about the air comment, not the crash)

What difference does it make if a turbine is kero start? that would only make a difference in the start sequence surely and not in flight??

+1

Here is a pic of a simple box I made to keep mine oriented the correct way Plus its easily removable by removing the rubber band that keeps it in place. It can be glued anywhere and works really well.

I was told that Hawk turbines tolerate bubbles, they just loose a small amount of power should one be 'swallowed', they use significantly less fuel than most other turbines = less fuel per flight = less weight and do not require any form of UAT = less weight + less hassle.
Seems worthy of consideration to me.

marcs

Marc,

I was thinking more of how to mount my UAT than replace my turbine

The Hawk turbines do seem very interesting though as we saw at JetPower.

M

Do the Hawks have screw on tailpipes? Looks like they are threaded at the end.

Hi Marc

i wasn't refering to the Hawk turbines, i didn't know about them. It was a referance to a semi private joke with Mark

Duncan

My previous supplier does not stock them anymore, will have a look around to see what I can find, I know M&R have them.

In my experience Its just that, during the start sequence if you have bubbles in the fuel feed it just seems to eat them without missing a beat, the pump then has no air to pick up as its been purged during the start, not having a UAT you don't have a bubble sitting there waiting to get into the fuel line either, it just seems to be that way, I know the editor of JI does not use a UAT as well, but uses a pleated paper filter which he makes himself.

Mike

Tut tut!

Duncan my post was just info, did not read anything into your post.

marcs

Andy don't think so, just the way its manufactured - interesting the fuel feeds are via Festo's mounted into the machined mounting brackets, so no feeding fuel pie through bypass cases

marcs

How's that then? I thought the idea of a UAT was that it trapped the air and stopped bubbles getting to the engine??


Also I don't think them Orbit type filters are too good. I've had one or two and seen loads that although they look clean, over time become restrictive and actually cause fuel pump cavatation followed by flames outs.

Jason

Any air in the UAT has been introduced whilst filling, if you have air in your fuel lines after it has been purged and your clunk is submerged then your plumbing has a leak and is drawing in air.

Like any filter you need to clean them occasionally, if you have a filter clunk and fill from the UAT you are filling on the wrong side of the filter clunk, you should have an additional filling point on your main tank to fill from rather than through the UAT IMO.

I have used the Orbit clunk now for about two years without any problems on 120 size and under, but have heard of some problems with large turbines of 160 size and over, not having that size turbine I can't comment, but what I have tried is drawing fuel out of the tank with my fill station at max speed without any cavitation and the fuel was taken out down to the last few onz, it was very strange to watch fuel being drawn out of the tank from below the top of the Orbit clunk without any air in the line.

Mike

Respectfully, I find the "start" qualifier to be nonsensical. I don't understnd how the start plumbing matters once the engine is running (?) Further, I disagree that any of these turbines are tolerant of ingesting air. This has not been my experience at all, nor the experience of many, many particapants and various threads on the topic.

I thrilled that u are not expreiencing any issues, truly. But I don't think that your case is typical ???