Do Fuel Flow Transducers Always need firesleeve

[Grandmas Flying Couch]

Here is my ft-60 it has 45s in and out.  I know that's not the best but after futzing for a day and a half this is it.  Is firesleeve necessary here?  I know it's more to protect the red cube from heat than safety.  Your fuel pump, fuel servo, and fuel spider don't have fire sleeve and they are aluminum.  What do you guys think?  

[A64Pilot]

The lines must have fire sleeve, but I’ve not seen it on the EI fuel transducers, assumption is if they need cooling, it’s provided by fuel flow.

However EI customer service is outstanding, if you’re unsure give them a call.

Ideally you want straight lines in and out but with 45’s it will probably be fine.

[47U]

24 minutes ago, Grandmas Flying Couch said:

I know that's not the best but after futzing for a day and a half this is it

The red cube looks to be well away from the #4 exhaust stack, but I’m wondering if you were able to maintain the “4” per foot” slope from the xducer to the fuel servo… 

 

[Grandmas Flying Couch]

13 hours ago, A64Pilot said:

The lines must have fire sleeve, but I’ve not seen it on the EI fuel transducers, assumption is if they need cooling, it’s provided by fuel flow.

However EI customer service is outstanding, if you’re unsure give them a call.

Ideally you want straight lines in and out but with 45’s it will probably be fine.

Thanks I like it open like this.  I can see if anything moves.  I hope it's fine with 45s, they mention 90s in the manual.  

[Grandmas Flying Couch]

12 hours ago, 47U said:

The red cube looks to be well away from the #4 exhaust stack, but I’m wondering if you were able to maintain the “4” per foot” slope from the xducer to the fuel servo… 

 

It's about 3.5 inches, the wife would guess seven but that's because I lie to her all the time.  It's about 3.5 inches over 14 inches.  

[Guest]

20 hours ago, Grandmas Flying Couch said:

Here is my ft-60 it has 45s in and out.  I know that's not the best but after futzing for a day and a half this is it.  Is firesleeve necessary here?  I know it's more to protect the red cube from heat than safety.  Your fuel pump, fuel servo, and fuel spider don't have fire sleeve and they are aluminum.  What do you guys think?  

I wouldn’t bolt it to your firewall, the hose between the fuel pump and transducer is taking all of the engine movement and transmitting it to the thin firewall material.

[Guest]

20 hours ago, A64Pilot said:

The lines must have fire sleeve, but I’ve not seen it on the EI fuel transducers, assumption is if they need cooling, it’s provided by fuel flow.

However EI customer service is outstanding, if you’re unsure give them a call.

Ideally you want straight lines in and out but with 45’s it will probably be fine.

While a fire sleeve would be desired, wouldn’t what’s in the IPC be the ultimate decision maker?

[cliffy]

Mine was mounted in the same area and worked fine, It was not secured to the footwell however

If you ever get a chance to see the engine start up with the cowl off you will understand why

It rocks and rotates quite a bit on start and the hoses take the brunt of the movement. 

[A64Pilot]

11 hours ago, M20Doc said:

While a fire sleeve would be desired, wouldn’t what’s in the IPC be the ultimate decision maker?

By IPC you mean parts catalog? If so I was taught the Maintenance manual took precedence.

But are we talking about the lines needing fire sleeve or the cube? I believe FAR’s require it on fuel lines past the firewall, but not sure.

The cube I installed on the C-210 and my Maule as well as dozens of turbine crop dusters and we never put anything on it, the crop dusters were IAW our factory drawings as we were the first aircraft to put the MVP-50 on as Certified and not under an STC, but I’m sure we had to meet EI’s installation requirements.

 

[cliffy]

39 minutes ago, A64Pilot said:

By IPC you mean parts catalog? If so I was taught the Maintenance manual took precedence.

But are we talking about the lines needing fire sleeve or the cube? I believe FAR’s require it on fuel lines past the firewall, but not sure.

The cube I installed on the C-210 and my Maule as well as dozens of turbine crop dusters and we never put anything on it, the crop dusters were IAW our factory drawings as we were the first aircraft to put the MVP-50 on as Certified and not under an STC, but I’m sure we had to meet EI’s installation requirements.

 

I don't believe Pt 91 requires fire sleeve on anything fwd of the fire wall  Could be wrong but I don't think so.

The MM always takes precedence 

[Guest]

40 minutes ago, A64Pilot said:

By IPC you mean parts catalog? If so I was taught the Maintenance manual took precedence.

But are we talking about the lines needing fire sleeve or the cube? I believe FAR’s require it on fuel lines past the firewall.

The cube I installed on the C-210 and my Maule as well as dozens of turbine crop dusters and we never put anything on it, the crop dusters were IAW our factory drawings as we were the first aircraft to put the MVP-50 on as Certified and not under an STC, but I’m sure we had to meet EI’s installation requirements.

 

The maintenance manual for the OP airframe says nothing about hose type, the IPC part number will break down to hose type and fire sleeved or not. The IPC would be FAA approved data would it not?

The STC for the engine monitor will call out the requirement for fire sleeve on the flow transducer.

[A64Pilot]

51 minutes ago, cliffy said:

I don't believe Pt 91 requires fire sleeve on anything fwd of the fire wall  Could be wrong but I don't think so.

The MM always takes precedence 

I think your probably right, but I think I remember a requirement to inspect the lines for fire hazards or some other verbiage  and inspectors can take that to mean fire sleeve. I’ll look, I think I know where it’s at.

‘Here http://www.aero.ing.unlp.edu.ar/catedras/archivos/ab_7a.pdf under section 70, this goes back to the 30’s but unless superseded it’s still applicable.

But anyway I think an inspector can use this to say that without firesleeve, you have a fire hazard and therefore are unsafe.

(A) The engine, ignition, fuel, oil, and cooling systems and all accessories normally included in an airplane power plant shall be so designed and installed as to reduce to a minimum the chances of failure to function while in the air, and insofar as is possible, to prevent fires during flight or in the event of a crash. Every effort should be made by the manufacturer toward fire prevention, in addition to compliance with the various specific requirements previously outlined. Engine installations and fuel and oil systems will be critically inspected for possible fire hazards and any questionable details or methods will be rejected as unsafe.

[cliffy]

This info is all for "certification"  and not "maintenance

In addition it has been superseded  by both CAR3 and Part 23 for light aircraft and Part 25 for Transport category aircraft.   

[A64Pilot]

12 hours ago, cliffy said:

This info is all for "certification"  and not "maintenance

In addition it has been superseded  by both CAR3 and Part 23 for light aircraft and Part 25 for Transport category aircraft.   

It is, but once Certified it has to be maintained to Type data.

So in other words I doubt a Manufacturer could get anything Certified without fire sleeve, I know where I worked it wasn’t even considered. No way would ATL ACO consider it I’m sure.

Even my 46 Cessna has a fire sleeved line from the Gascolator to the Carburator.

I don’t think it has been superseded unless CAR 3 / FAR 23 states it does, regs don’t die, they just get piled onto

So, even before CAR3 even existed, back almost 100 years ago a regulation pretty much made non fire sleeved rubber lines not applicable, do you think that’s been relaxed?

As a licensed mechanic no way would I consider installing a non fire sleeved line as I’m certain that I would lose that argument with an Inspector.

[A64Pilot]

On 2/20/2023 at 6:24 PM, M20Doc said:

The maintenance manual for the OP airframe says nothing about hose type, the IPC part number will break down to hose type and fire sleeved or not. The IPC would be FAA approved data would it not?

I know the Thrush IPC as of when I retired about 5 years ago was NOT FAA approved, I can’t speak to other manufacturers.

The reason it wasn’t was not because the FAA had any issue with it, but because there just wasn’t anyway they could ensure it’s accuracy, way too many parts.

The POH of course is FAA approved, but compared to a parts manual it’s a very simple document.

[cliffy]

My 46 C-140 (when I owned for 25 years) never had a fire sleeve on it. It came that way to me. Came from the factory that way. 

Don't remember seeing fire sleeves on any lines on a DC-3. 

I'll bet the vast majority of Mooneys have no fire sleeve on the oil cooler lines if they are 303 hose.

I've seen many many Cessnas without fire sleeves in the engine compartment

I'm willing to bet that an Inspector "could" try to require sleeves but I really don't think they are mandated by regulation. 

Best practices would be to use same but again we don't go by "best practices" as a regulation in aviation. 

I do wonder when fire sleeves were invented as I have no idea. 

Its no different than today with so many A&Ps not wanting to even make hoses as we did 40 years ago in house without a second thought

Times change and the interpretation of regulations changes with the times. 

Early on we used copper tubing for fuel lines but no more. 

Now a days on new construction fire sleeves might/should be the way to go. In the past not so much.  

[EricJ]

On 2/20/2023 at 4:24 PM, M20Doc said:

The maintenance manual for the OP airframe says nothing about hose type, the IPC part number will break down to hose type and fire sleeved or not. The IPC would be FAA approved data would it not?

If it is FAA Approved pages or sections are marked such individually.   There are no pages in my IPC that say "FAA Approved".   

[EricJ]

On 2/20/2023 at 4:22 PM, cliffy said:

I don't believe Pt 91 requires fire sleeve on anything fwd of the fire wall  Could be wrong but I don't think so.

The MM always takes precedence 

As far as I can tell you're right.    However, any aircraft built with hoses needing to meet FAA TSO - C53a or TSO - C75 generally require firesleeve or equivalent.

I don't think that applies to any of our airplanes, though.

[chriscalandro]

The installation guide for the red cube specifically says it needs fire sleeve. 
 

 

[A64Pilot]

46 minutes ago, chriscalandro said:

The installation guide for the red cube specifically says it needs fire sleeve. 
 

 

Some may argue that should isn’t mandatory, but I agree with you. Plainly EI wants it.

We never did, so either that’s new, or we were incorrect in our installations.

[A64Pilot]

1 hour ago, EricJ said:

If it is FAA Approved pages or sections are marked such individually.   There are no pages in my IPC that say "FAA Approved".   

From memory I don’t think the MM is “FAA approved” either.

But Crop Dusters are honestly treated a little different than people carrying airplanes, so maybe can’t imply from one to the other.

I can tell you that we Certified and were delivering aircraft before the IPC or MM were published. They did catch up, but honestly had errors, quite a few actually.

A proper IPC is a mind boggling amount of work, a truly incredible amount of work. Imagine getting every nut, bolt, screw, cotter pin etc. correct.

[oregon87]

Per our installation instructions.  While the attachment specifies the FT-90 flow transducer, the sentence regarding fire sleeving applies to all our flow transducers.  Worth noting, these instructions apply to installations with our instrumentation.  If our flow transducers are to be interfaced with a third party instrument, our STC'd instructions do not apply as our flow transducers are not STC'd independently.  

Additionally, 90° fitting are not expressly prohibited, however, their use should not disrupt flow to the engine, but can disrupt the laminar flow of fuel to the transducer's impeller, resulting in erratic fuel flow indications.  Whenever possible, 45° fittings would be preferred.

 

 

Edited February 22, 2023 by oregon87

[Guest]

4 hours ago, chriscalandro said:

The installation guide for the red cube specifically says it needs fire sleeve. 
 

 

Here’s that old “should”versus “must” debate.  I’d default to best practice, add a firesleeve.  It doesn’t cost much for the improved life of the transducer.

[A64Pilot]

21 hours ago, M20Doc said:

Here’s that old “should”versus “must” debate.  I’d default to best practice, add a firesleeve.  It doesn’t cost much for the improved life of the transducer.

That and what the Manufacturer rep posted about within 6” of an exhaust pipe, but I agree having it could help, and I see no downside.

[Grandmas Flying Couch]

On 2/22/2023 at 3:30 PM, M20Doc said:

Here’s that old “should”versus “must” debate.  I’d default to best practice, add a firesleeve.  It doesn’t cost much for the improved life of the transducer.

I freed it from the foot box and fire sleeved it.  I have smaller fire sleeve on the way but a neighbor gave me this stuff for now.  Thanks guys!