5 Year Rubber Replacement?

[Sling 2 Pilot]

So, how important is it to replace the hoses on a 912 ULS, LSA at the 5 year anniversary? The plane is hangered since new with less than 300 hours SN.

[3Dreaming]

If it is SLSA you will have to follow the timeframe as spelled out in the aircraft manufactures maintenance manual. If it is ELSA you will have some latitude. Carb diaphragms, float needles, and carb sockets are threes things that I would not let go past 7 years. Fuel pump and pressure issues seem to pop up after 5 years, so be aware. I have seen some coolant hoses that were rotten at 5 years, but they were not OEM hoses. Depending on installation some use fuel and oil hoses that are considered lifetime and replaced on condition.

[drseti]

In my opinion, omitting a hose replacement at 5 years is false economy, regardless of legalities. Consider the possible consequences of a hose failure:

(1) coolant hose - if you lose all the dexcool, you need to reduce power immediately to 4000 RPM, set up slow flight, and limp to the nearest airport. Not doing so can result in warped heads, which (though generally not fatal) will be very expensive.

(2) oil hose - if you lose engine oil, you're going to have to land immediately, lest the engine seize. Otherwise, you'll very quickly find yourself flying a glider. (See my EAA webinar on just such an experience, at https://avsport.org/webinars/videos/MIF.mp4).

(3) fuel hose - a failure here can easily lead to an engine fire. At that point, you have very few options, and low odds of survival.

Let's say a full rubber replacement, materials and labor, costs $5000 (probably a high estimate). Can you really tell me your life isn't worth $1000 a year?

[Sling 2 Pilot]

Thanks all, your answer's are very much appreciated. It appears my aircraft ownership days are numbered. I’ll probably look to move on next year.

[Warmi]

In my opinion, omitting a hose replacement at 5 years is false economy, regardless of legalities. Consider the possible consequences of a hose failure:

(1) coolant hose - if you lose all the dexcool, you need to reduce power immediately to 4000 RPM, set up slow flight, and limp to the nearest airport. Not doing so can result in warped heads, which (though generally not fatal) will be very expensive.

(2) oil hose - if you lose engine oil, you're going to have to land immediately, lest the engine seize. Otherwise, you'll very quickly find yourself flying a glider. (See my EAA webinar on just such an experience, at https://avsport.org/webinars/videos/MIF.mp4).

(3) fuel hose - a failure here can easily lead to an engine fire. At that point, you have very few options, and low odds of survival.

Let's say a full rubber replacement, materials and labor, costs $5000 (probably a high estimate). Can you really tell me your life isn't worth $1000 a year?

Absolutely agree with every word but I am curious .. wouldn’t cutting off fuel in the cockpit render engine fire a self limiting event ( obviously still very much a catastrophic failure ) - I do test my fuel valve now and then and the engine will run for about 2 maybe 3 minutes with the fuel valve in the off position …

[drseti]

I do test my fuel valve now and then and the engine will run for about 2 maybe 3 minutes with the fuel valve in the off position …

That's probably correct - but 2 or 3 minutes of engine fire could possibly be enough to cause asphyxia in the cabin. I wouldn't want to risk it.

[3Dreaming]

In my opinion, omitting a hose replacement at 5 years is false economy, regardless of legalities. Consider the possible consequences of a hose failure:

(1) coolant hose - if you lose all the dexcool, you need to reduce power immediately to 4000 RPM, set up slow flight, and limp to the nearest airport. Not doing so can result in warped heads, which (though generally not fatal) will be very expensive.

(2) oil hose - if you lose engine oil, you're going to have to land immediately, lest the engine seize. Otherwise, you'll very quickly find yourself flying a glider. (See my EAA webinar on just such an experience, at https://avsport.org/webinars/videos/MIF.mp4).

(3) fuel hose - a failure here can easily lead to an engine fire. At that point, you have very few options, and low odds of survival.

Let's say a full rubber replacement, materials and labor, costs $5000 (probably a high estimate). Can you really tell me your life isn't worth $1000 a year?

(1) As I said I have seen some rotten coolant hoses, but the only coolant losses I am aware of were related to a hose coming off a fitting. This can happen with any aged hose.

(2) If it is an OEM type oil hose I would recommend replacing them. If they are a Teflon hose they should be good.

(3) Rubber fuel hoses should be replaced, but if they are Teflon hoses Rotax says they do not need to be replaced.

I have seen some airplanes with Teflon fuel and oil hoses. Some are also using silicone coolant hoses which are also considered a lifetime hose.

[3Dreaming]

Absolutely agree with every word but I am curious .. wouldn’t cutting off fuel in the cockpit render engine fire a self limiting event ( obviously still very much a catastrophic failure ) - I do test my fuel valve now and then and the engine will run for about 2 maybe 3 minutes with the fuel valve in the off position …

That 2-3 minutes is with the fuel flowing through two small orfices in the carburetor. If you have an open line the fuel will dran out in a matter of seconds. Regardless any fire whether it is fuel, oil or otherwise is not a good thing.

[drseti]

Of course, Tom is right about Teflon hoses. What we're talking about here is 5 year rubber replacement, not Teflon replacement.

[3Dreaming]

Of course, Tom is right about Teflon hoses. What we're talking about here is 5 year rubber replacement, not Teflon replacement.

My point is that depending on the airplane, the rubber replacement task may not be as big of deal as others.

[drseti]

Point well taken.

[Sling 2 Pilot]

I’m moving forward with it, but all my research points to just another way to up the profit margin for a shop. That is of course, if the plane, car, whatever vehicle the hoses are in and attached to was maintained properly and hasn’t been exposed to wear and tear beyond normal operating parameters. In most cases the actual manufacturer of said hoses state a longer life span.

Dammed if you do, dammed if you don’t…change em that is. Mine will be getting changed.

[chicagorandy]

I have no horse in this race (sadly) but I do note the rather unique nature of hose failures in pursuits such as aviation and scuba diving vs say cars, trucks and motorcycles. In the latter you might end up stranded at the side of the road, in the former you might die.

Just sayin'.

My personal 'no horse' condition is directly related to the level of my discretionary income, NOT my life-long passion for aviation. In fairness no one has ever said that flying airplanes was for the faint of wallet - lol - so I've "made do" with RC flying machines and Flight Sim 2020.

[JJay]

What we're talking about here is 5 year rubber replacement, not Teflon replacement.

Backed up by Rotax SI-912-022

[drseti]

The Rotax line maintenance manual, section 05-10-00 paragraph 2.1 page 8, says:

The following components and systems must be replaced every 5 years:

... all rubber hoses of the fuel system (incl. Teflon hoses)