Emergency landing at Sydney beach

[facthunter]

Yes Spare us.  Splitting a system into sections and and blowing it out with air is not a bad idea. Planes spend a lot of time not flying.

 re the push rods, have you a picture of each end?  Second hand ones are as good as new ones for this exercise..Nev

[kgwilson]

Once when I drained the fuel from my tank I looked in and saw a tiny bit of rubber sitting on the top of the fuel outlet tube that is about 30mm from the bottom of the tank sump. Somehow it had not restricted the fuel flow enough to reduce power so I was lucky. I sucked it out with my hand held vacuum with a long tube on it & I could not work out where it had come from. Next I got my borescope & went looking all through the tank but found nothing.

[Thruster88]

Another difference I see between certified and RAAus type aircraft is fuel tank finger strainers. Certified aircraft always have them and we check some depending on the system of maintenance. I fitted one to the thruster many years ago after a piece of my farm machinery suffered a blockage at the fuel outlet. 

 

In the case of the tecnam the blockage was not at the fuel tank but may have originated from a tank.

[KRviator]

The RVs have an even simpler one, a piece of standard fuel tubing. Bent to sit a bees d!ck off the bottom of the tank, a flared fitting on one end, squashed flat at the other, with a series of thin hacksaw cuts partway through it.

 

I couldn't imagine anyone flying without something to catch the bigger contaminants before they reach (and/or) block the filter.

[RFguy]

A blade of grass would do it on some LSAs, getting into the wrong place, just blowing around while the caps are off during refueling. 

 

 

 

 

 

[turboplanner]

2 hours ago, RFguy said:

A blade of grass would do it on some LSAs, getting into the wrong place, just blowing around while the caps are off during refueling. 

 

 

 

 

 

You'd be surprised what comes out of a Jerry Can without a gauze funnel screen. most of it works its way through the carb at full throttle, gets burnt. I have filter bowls on the JD Mower and tractors and that picks up a lot of sand/mud. The JD Mower tank  has a white interior and with a torch you can usually see half a forest sliding around on the floor. Most of that can be sucked out by a 6 mm syphon hose with enough drop to create strong suction. Then there are the things like you mentioned which drop in when the cap's off, from a hose, from the cap which you sat in some dirt, from dust on the hose/funnel, Spiders, ants, spider web etc from the Jerry Can/hose /funnel..

 

Then there are the kids and accidents, when a solid object falls into the tank and is sucked up the suction pipe.

 

That's why I think thruster's finger screen is so good it would still alow supply with most big objects in the tank.

Edited May 31, 2021 by turboplanner

[facthunter]

 A primary finger filter is in even a tractor. Your fuel caps aren't usually locked when you overnight in the open either. You can buy various grades of brass mesh to make your own filter. If it's fine you look at it more often. Nev

[Old Koreelah]

14 minutes ago, turboplanner said:

...Then there are the things like you mentioned which drop in when the cap's off...

These days I’m religious about using Mr. Funnel.

 

During one cold night trip in the 70s I was gobbling a chocolate bar as I refuelled the bike. A piece fell into the open tank. Weeks later the bluddy bike stopped on the Putty Road. A blob of sultana had clogged the fuel tap outlet.

[RFguy]

I fill using the dual filter funnel, and very careful that the funnel itself is super clean.
Ya know when working on water pressure sensors in dams and ponds, the tiny breather holes got filled up with tiny snails.

Howover, I will retrofit the Jabiru with some sort of broad mesh as to catch whatever could clog down stream. ideally, meshes need to be progressively finer as to prevent a single orifice blockage soemwhere down stream.

 

[Old Koreelah]

56 minutes ago, RFguy said:

... I will retrofit the Jabiru with some sort of broad mesh as to catch whatever could clog down stream. ideally, meshes need to be progressively finer as to prevent a single orifice blockage soemwhere down stream.
 

I thought they were standard in Jabs. I fitted a pair of finger filters (like those in T88’s post) taken from a Jab kit.

[Jaba-who]

5 hours ago, RFguy said:

I fill using the dual filter funnel, and very careful that the funnel itself is super clean.
Ya know when working on water pressure sensors in dams and ponds, the tiny breather holes got filled up with tiny snails.

Howover, I will retrofit the Jabiru with some sort of broad mesh as to catch whatever could clog down stream. ideally, meshes need to be progressively finer as to prevent a single orifice blockage soemwhere down stream.

 

Finger strainers are standard in Jabs 

[RFguy]

And there is it- it's behind  the header-tank outlet barb. so that's where it is.  Despite my Jabiru company related engine troubles, I will be sticking with the airframe. 

 

 

Edited June 1, 2021 by RFguy

[Jaba-who]

2 hours ago, RFguy said:

And there is it- it's behind  the header-tank outlet barb. so that's where it is.  Despite my Jabiru company related engine troubles, I will be sticking with the airframe. 

 

 

There are also  similar ones in the main wing tank outlets. At least in mine which is a 2006 model J430. I remember installing them in the tanks when I built it. So all up there’s at least three. 

[Old Koreelah]

Removing them from the tank to clean off accumulated debris is pretty easy; you just need the correct-sized replacement O-ring. 

[RFguy]

Yeah when I want to know "what is behind" I go to the Jabiru constructor's manuals for photos....

Edited June 1, 2021 by RFguy

[Kyle Communications]

On 31/05/2021 at 2:59 PM, RFguy said:

Mark, what orifice  ID and what size bit debris ? Maybe I need to take one apart to understand the ease this can happen. I was going to say "understand the gravity" but that would be a little pun-ish.

The main fuel feed on a Sav comes out under the fuselage then through a tap on the floor then it goes out a 10mm alu pipe under the front floor and the metal pipe does almost right angle curve then direct up the firewall and mine then went to a gascolator. I found it by checking the gravity flow from the tanks to the gascolator and kept sectioning until of course the last piece of pipe was the one curved around the firewall from under the aircraft. I took that piece of pipe out and blew the compressor through it and out popped this bit of white plastic about 8mm x 12mm and it had got caught in the curved area and half blocked off the pipe...took a while to find

 

[F10]

Interesting. I’m sure fuel tank venting is sometimes neglected, but it is vital for good fuel flow. My Gazelle vents are a clever design, butI think are a bit prone to blocking up if not kept an eye on. I would prefer small tubes on the fuel caps facing into wind, like on a Kitfox. Also, yes I actually remember thinking this very morning, that I need to pop off the collector bowl on the gascolator, clean it and check the gascolator mesh filter. This is a very fine mesh, so can become clogged up quite easily. This leads me to my question, you can get these scintered bronz inline filters for cars and bikes, some are in a transparent casing, are these legal to use in an aircraft? You would think an inline filter might stop debris clogging up carbies?

[Thruster88]

1 hour ago, F10 said:

Interesting. I’m sure fuel tank venting is sometimes neglected, but it is vital for good fuel flow. My Gazelle vents are a clever design, butI think are a bit prone to blocking up if not kept an eye on. I would prefer small tubes on the fuel caps facing into wind, like on a Kitfox. Also, yes I actually remember thinking this very morning, that I need to pop off the collector bowl on the gascolator, clean it and check the gascolator mesh filter. This is a very fine mesh, so can become clogged up quite easily. This leads me to my question, you can get these scintered bronz inline filters for cars and bikes, some are in a transparent casing, are these legal to use in an aircraft? You would think an inline filter might stop debris clogging up carbies?

It reads like your aircraft has all the filtration required. Another filter would be a solution to a non existent problem and may even have unintended consequences.  

[facthunter]

Carburetters don't need the degree of filtering that some injection systems do. If some $#1T was turning up in the bowl of the carb. something should be done. Old fuel does degrade and that can haopen anywhere in the system. Pity the carb bowls can't be easily drained of fuel .Nev

[Old Koreelah]

3 minutes ago, facthunter said:

... Pity the carb bowls can't be easily drained of fuel .Nev

It should be easy to tap a tread and install a drain valve.

[facthunter]

You only need a screw there, but I doubt there's enough metal thickness to safely do it. It would also have to be safety wired or tabbed.  Nev

[turboplanner]

56 minutes ago, Old Koreelah said:

It should be easy to tap a tread and install a drain valve.

I've done that on race cars to get rid of methanol after racing, and it was easy, but on a race car everything is checked prior to the next meeting. I wouldn't recommend it on an aircraft because there's too much chance of the nut coming loose on the thread and starting a leak.

[skippydiesel]

Tank breather/vents can also be a source of contaminants (mainly dust and insects) - I fitted my breather with a gauze in line filter. I rarely get any material in my fuel filters. I guess my anal attention to fuel cleanliness and thousands of litres of fuel  flushing the system has has payed off.

[kgwilson]

My breathers come out the top of the tanks & then down and exit the bottom of the fuselage and wings. The alloy 1/4 tube is cut at 45 deg angle in to wind to provide positive pressure in the tanks. Bugs & dust could be blown in but there is a long trip up the tube to get into the tank & so far I have not had any debris in the filter or the carb bowl. I can remove the carb bowl quite easily at it is at the bottom rear of the Jab engine. I just have to take the bottom plate that fits around the noseleg & exhaust exit points (5 machine screws into nut plates on the lower cowl) off.

[F10]

On 03/06/2021 at 7:00 PM, Thruster88 said:

It reads like your aircraft has all the filtration required. Another filter would be a solution to a non existent problem and may even have unintended consequences.  

Yes I agree, and a mate at my club said the same...I just drain the collector tank and gascolator twice or three times if I see any UFO’s (unidentified floating objects). Still creeps me out a bit...those jets and for example choke fuel drilling’s in these Bings are pretty small and fine. I think you can pop the bowls off pretty easily with that clip. Easier than most car or bike carbs. Mine aren’t wire locked....perhaps they should be? But it takes a bit of force to pop the clips holding the bowls of, so not somthing that will easily come undone.