To filter or not to filter that’s is the question?
11-16-2018, 01:43 PM
#1
To filter or not to filter that’s is the question?
ok guys, as it says I’m the subject line, how many have a fuel filter in the plane and how many do not? And what’s your reasoning for each?
I’m 50/50, my fuel is filtered 4 times before it gets to the turbine. Felt pick up in filler supply tank, Filter on supply line on my filller tank, UAT has a filter then I have the “standard” filter in line before the turbine.
So I’ve seen many guys cut out the standard fuel filter before the tirbine and feel that the filter in the filler tank and UAT are sufficient.
I have cleaned my filters on other jets and have never seen that filter dirty. Sure the filter in my main filler tank is gets dirty though, but the little inline filter is always clean. The filters in my A10 are friggin burried deep in the plane and will be a huge PIA to service. So I was questioning the need for them.
Whats everyone’s take?
I’m 50/50, my fuel is filtered 4 times before it gets to the turbine. Felt pick up in filler supply tank, Filter on supply line on my filller tank, UAT has a filter then I have the “standard” filter in line before the turbine.
So I’ve seen many guys cut out the standard fuel filter before the tirbine and feel that the filter in the filler tank and UAT are sufficient.
I have cleaned my filters on other jets and have never seen that filter dirty. Sure the filter in my main filler tank is gets dirty though, but the little inline filter is always clean. The filters in my A10 are friggin burried deep in the plane and will be a huge PIA to service. So I was questioning the need for them.
Whats everyone’s take?
11-16-2018, 02:24 PM
#2
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I have always used a filter between the pump and the turbine, i've seen a new pump throw off grey matter during break in which reinforced my thought process in this regard.
11-16-2018, 03:03 PM
#4
My preference
The most recent jet that I finished last month, I only have the UAT as the filter. I have one filter on the fuel pump can after the can pump and prior to filling the jet. So, two filters prior to being burned. The previous jet, I have an additional filter prior to filling the UAT. So, 3 filters prior to being burned. I quit using an inline filter after the fuel pump/valve several years ago. The main reason is to eliminate another restriction and leaking point. The only reason to have the filter after the onboard fuel pump and valve, is the internal failure of the pump side of the electric fuel pump. Seems to be very rare, if never. Reo is one of the few that I have ever heard of having problems, so not impossible. There is another reason to have a filter after the pump/valve is for warranty reasons, so read the fine print. Manufacturers will take the most conservative approach. The UAT being the main fuel system filter; I personally feel to be enough filtration. The new cylinder UAT have the micro stone filter when the fuel is leaving the UAT. Extremely fine filter. The micro bag filter in the BVM and other same style UAT filters is also a very fine micro filter. Let’s also remember that the jet fuel truck has additional filters. We as pilots are likely to contaminate the fuel when transferring from one 5 gallon can to the main fuel pump can. We are our own worse enemies.
The situation of creating onboard microorganisms can happen if after flying, the fuel isn’t drained. And even if you drain the fuel, not all of it is pumped out. Here in Florida and other gulf states, during the summer, we are usually very humid. The fuel left onboard could create condensation if you store your jets in the house in a/c. The water is what is needed to grow the bugs. If so, chances are the UAT filter will clog and will either not start, or a flame out. Hopefully not on TO.
I do think that we over filter the fuel.
Take care! Dan
The situation of creating onboard microorganisms can happen if after flying, the fuel isn’t drained. And even if you drain the fuel, not all of it is pumped out. Here in Florida and other gulf states, during the summer, we are usually very humid. The fuel left onboard could create condensation if you store your jets in the house in a/c. The water is what is needed to grow the bugs. If so, chances are the UAT filter will clog and will either not start, or a flame out. Hopefully not on TO.
I do think that we over filter the fuel.
Take care! Dan
11-17-2018, 12:13 AM
#5
There is no discussion. If the pump is outside the turbine it needs the filter. If it’s a JetCat RXi there is the same JetCat filter under the purple cover.
11-17-2018, 04:24 AM
#7
Dave, you normally say smart stuff, but you are ASSuming that everyone is flying JetCat, and that everyone's engine is under warranty. I bet more then 75% plus aren't flying JetCat, and those that are, I bet more then 50% of them aren't under the whole 3 year limited warranty. And, even reading the JetCat limited warranty, there is NO mention that a inline filter after the pump is required to meet the JetCat Limited Warranty. The other 75% of those that aren't flying JetCat, a huge portion are flying the Life Time Limited Warranty engines, which there are more of those at are our field then any JetCat's, and then, there are those of us that don't fly any of those engines, our warranties are out and we do not have to meet anything but common sense, I know, that will be difficult for some, safety requirements. So, what and how we choose to operate our turbines is strictly our business and the "warranty" is our pocketbook. So, we can discuss other ways to skin the cat..........and not a JetCat.
11-17-2018, 06:36 AM
#8
If One is risk adverse, one puts in a filter after the pump. If One is risk tolerant, one may not put in a filter after a pump. Assuming the fuel is handled correctly and a filter is properly maintained, it seems to me that the highest risk for fuel system failure is when a new pump or fuel system component is installed. But, there are new risks introduced when a filter is installed (e.g. Potential leak, filter plugging, etc.) But, …
Jetcat took out the option on the RXi. Given that typically no manufacturer of any product adds anything that is unnecessary, typically due to added cost, it makes sense that a filter before the turbine is a good idea. To me, Jetcat is saying; The added risk of a filter before the turbine is greatly outweighed by the risk of a fuel pump or system passing on an impurity that clogs the start solenoid, etc.. Common sense prevailed and they further took out the initial installation risks by putting the filter in the turbine. Most, if not all, the other manufacturers tell you to install a filter after the pump. More common sense. So given the risks, we typically add filters. More common sense. If we do put in a filter, it has to be maintained. so we typically put them in where we can get at them and inspect for leaks. More common sense. To me, whether or not to put in a filter after the pump is a no brainer! Guess I am relatively risk adverse.
Jetcat took out the option on the RXi. Given that typically no manufacturer of any product adds anything that is unnecessary, typically due to added cost, it makes sense that a filter before the turbine is a good idea. To me, Jetcat is saying; The added risk of a filter before the turbine is greatly outweighed by the risk of a fuel pump or system passing on an impurity that clogs the start solenoid, etc.. Common sense prevailed and they further took out the initial installation risks by putting the filter in the turbine. Most, if not all, the other manufacturers tell you to install a filter after the pump. More common sense. So given the risks, we typically add filters. More common sense. If we do put in a filter, it has to be maintained. so we typically put them in where we can get at them and inspect for leaks. More common sense. To me, whether or not to put in a filter after the pump is a no brainer! Guess I am relatively risk adverse.
11-17-2018, 07:31 AM
#9
[QUOTE=Len Todd;12479407 But, there are new risks introduced when a filter is installed (e.g. Potential leak, filter plugging, etc.) But, …
Jetcat took out the option on the RXi. [/QUOTE]
The OP wants to know the practice of others. I am volunteering my years of experience with my engines and those of my students. Yes, most of the time there is a filter after the pump, because the manufacturer thinks that their fuel pump will fail. There's some confidence in your product. The electric side of the pump fails more than the fuel pump side.
So, IF you buy a JetCat RXI engine series, IF you get the clogged engine filter, those owners have to take the engine out of the jet and go through lost flying time and the expense of shipping the engine in for a simple clogged filter after their pump failed? This is also if the pilot is good enough to successfully land a flame out dead stick. What I have watched at the field, 50% plus aren't able to deal with a dead stick without substantial damage to the jet......maybe even a total of airframe and engine. All due to a filter that the owner operator can't access to clean of a manufacturer's failed fuel pump that created the issue to start?
I do truly get having filters to prevent damage, clogged fuel spray and hotspot fuel spray. IMHO, we over filter.
Jetcat took out the option on the RXi. [/QUOTE]
The OP wants to know the practice of others. I am volunteering my years of experience with my engines and those of my students. Yes, most of the time there is a filter after the pump, because the manufacturer thinks that their fuel pump will fail. There's some confidence in your product. The electric side of the pump fails more than the fuel pump side.
So, IF you buy a JetCat RXI engine series, IF you get the clogged engine filter, those owners have to take the engine out of the jet and go through lost flying time and the expense of shipping the engine in for a simple clogged filter after their pump failed? This is also if the pilot is good enough to successfully land a flame out dead stick. What I have watched at the field, 50% plus aren't able to deal with a dead stick without substantial damage to the jet......maybe even a total of airframe and engine. All due to a filter that the owner operator can't access to clean of a manufacturer's failed fuel pump that created the issue to start?
I do truly get having filters to prevent damage, clogged fuel spray and hotspot fuel spray. IMHO, we over filter.
11-17-2018, 09:36 AM
#10
My answer had nothing to do with JetCat. I'd recommend it with any turbine. Fuel choice is another thing. I've flown turbines for 20 years, I don't get flame outs.
My customers use filters and they don't get flame outs-on JetMunt (ignoring the instruction to put it on the suction side), Behotec and other brands they chose to use.
Rxi turbines don't have to be returned to the factory-its the same filter and a length of tube to change...but if your fuel requires a filter change...i'd change your fuel and fuel practices. I know we are not all lucky to have easy access to fuel, I wouldn't put JetA1 through one of my own turbines, I chose to buy expensive green house Kerosene. The cost extra is saved in turbine and model life.
Yes, people will operate without a filter, that's your choice. But as far as this thread I stick with my original answer. Use a filter. OK, not one of the 'toys r us' Festo glass ones, here people generally use the JetCat type F-30.
If you come to a UK meeting its 75% JetCat...maybe higher.
My customers use filters and they don't get flame outs-on JetMunt (ignoring the instruction to put it on the suction side), Behotec and other brands they chose to use.
Rxi turbines don't have to be returned to the factory-its the same filter and a length of tube to change...but if your fuel requires a filter change...i'd change your fuel and fuel practices. I know we are not all lucky to have easy access to fuel, I wouldn't put JetA1 through one of my own turbines, I chose to buy expensive green house Kerosene. The cost extra is saved in turbine and model life.
Yes, people will operate without a filter, that's your choice. But as far as this thread I stick with my original answer. Use a filter. OK, not one of the 'toys r us' Festo glass ones, here people generally use the JetCat type F-30.
If you come to a UK meeting its 75% JetCat...maybe higher.
11-17-2018, 09:42 AM
#11
I recommend you filter, there is always a chance of pumps and other trash getting to the turbine causing issues, I would much rather replace a pump/filter than the cost of a tear down to fix the turbine itself. Cheers!
11-17-2018, 10:48 AM
#13
Looks like I’m a minority. Cool!
I have seen more problems arise when using filters than with out. And that is MY personal experience. And that’s not counting the number of times I’ve seen leaks, trapped bubbles, etc..in other people’s jets.
And I don’t “get” flame outs either.
Isn’t it grand that we can all get so many different success stories!
I have seen more problems arise when using filters than with out. And that is MY personal experience. And that’s not counting the number of times I’ve seen leaks, trapped bubbles, etc..in other people’s jets.
And I don’t “get” flame outs either.
Isn’t it grand that we can all get so many different success stories!
Last edited by ravill; 11-17-2018 at 10:50 AM.
11-17-2018, 12:18 PM
#15
Looks like I’m a minority. Cool!
I have seen more problems arise when using filters than with out. And that is MY personal experience. And that’s not counting the number of times I’ve seen leaks, trapped bubbles, etc..in other people’s jets.
And I don’t “get” flame outs either.
Isn’t it grand that we can all get so many different success stories!
I have seen more problems arise when using filters than with out. And that is MY personal experience. And that’s not counting the number of times I’ve seen leaks, trapped bubbles, etc..in other people’s jets.
And I don’t “get” flame outs either.
Isn’t it grand that we can all get so many different success stories!
11-17-2018, 01:39 PM
#18
I use two filters on my fuel container. I have a filtered clunk and an inline filter after the pump on the hose that I connect to the jet. I also have a filter in my UAT plus one filter between the pump and the turbine. Logic is as follows, I am protecting against foreign debris from the truck at the airport (i use Jet A-1), & I filter for potential debris potentially introduced by the fuel can pump and turbine pump. It's cheap insurance.
11-17-2018, 02:19 PM
#20
Great pictures! Thank you for coming to the event. It is only the second year for the event and the club is trying to get another big event going, besides the Gathering of the Giants in the spring. All of us under the tents were talking about your great sound. Hard to beat.
11-17-2018, 02:22 PM
#21
Dave, you normally say smart stuff, but you are ASSuming that everyone is flying JetCat, and that everyone's engine is under warranty. I bet more then 75% plus aren't flying JetCat, and those that are, I bet more then 50% of them aren't under the whole 3 year limited warranty. And, even reading the JetCat limited warranty, there is NO mention that a inline filter after the pump is required to meet the JetCat Limited Warranty. The other 75% of those that aren't flying JetCat, a huge portion are flying the Life Time Limited Warranty engines, which there are more of those at are our field then any JetCat's, and then, there are those of us that don't fly any of those engines, our warranties are out and we do not have to meet anything but common sense, I know, that will be difficult for some, safety requirements. So, what and how we choose to operate our turbines is strictly our business and the "warranty" is our pocketbook. So, we can discuss other ways to skin the cat..........and not a JetCat.
Last edited by skunkwurk; 11-17-2018 at 02:38 PM.
11-17-2018, 04:33 PM
#22
Some have mentioned that it’s recommended in the manual. The manual for the ATJ140 saga to put the filter between the UAT and pump. So on the suction side. Also none of my flame outs have been caused by pump failure or debris of any kind. So this is another reason I am considering going filterless. Add to the fact that they are burried DEEP in the airframe and it’s a full day of work to service them.
11-17-2018, 05:07 PM
#24
Some have mentioned that it’s recommended in the manual. The manual for the ATJ140 saga to put the filter between the UAT and pump. So on the suction side. Also none of my flame outs have been caused by pump failure or debris of any kind. So this is another reason I am considering going filterless. Add to the fact that they are burried DEEP in the airframe and it’s a full day of work to service them.