Another 5 year hose replacment question

Re: Another 5 year hose replacment question

by Roger Lee » 10 years ago

Roger Lee

131 5.38k 5.44k

Once out of the factory engines tend to move to an MFG fairly quickly. Vans also moves engines fairly quickly. Technically the mid 2012 would be the date, but Rotax only supplied you with the 17mm coolant hoses and some fuel line off the fuel pump and between the carbs. Was the engine left stored in it's box and wrap or just left sitting out on a bench? Outside its packaging it is exposed to ozone, UV and chemicals in the air. Hose does have a shelf life.
I do a lot of 5 year hose changes on the LSA aircraft and from what I have seen over the years it wouldn't bother me to use your mid 2014 date, but I would stick to that time and not go beyond. Even though hose does have a shelf life just sitting around yours never really had any heat exposure and heating and cooling cycles.
Just a side question. Did you put all your oil and fuel lines in fire sleeve?


Now that I have said this you may get differing comments from other Rotax people here and it may all be right and just boil down to your personal decision.

---

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: Another 5 year hose replacment question

by Robert Melis » 10 years ago

Robert Melis

2 6 15

Thanks Roger,
The engine was left in its crate and wrapping until just prior to installation, and all oil and fuel lines are fire sleeved. Thanks for your advice. I'm sure there must be many builders who have a similar story to tell.

Re: Another 5 year hose replacment question

by Rob Seaton » 10 years ago

Rob Seaton

3 1.32k 251

My 2 cents: According to MIL-STD-1523A service life of the hoses should start with the engine installation date.

Re: Another 5 year hose replacment question

by Robert Melis » 10 years ago

Robert Melis

2 6 15

I had a look for MIL-STD-1523A, but as far as I can determine, that Standard applied to O-rings and was cancelled in 1995. AS1993 covers hoses, and it says 32 quarters from date of manufacture (as far as I can figure out). On that basis Rotax's requirement for 5 year hose replacement implies that up to 12 quarters are assumed to have elapsed between hose manufacture and when the hoses are installed in the engine at the factory. It may be nowhere near 12 quarters in practice, but I guess that Rotax have to assume the worst case as per the Standard.

http://www.satoriseal.com/technical/technical_articles/shelf_life.htm
http://www.scribd.com/doc/102944530/SAE-AS-1933-1998-R2004#scribd

Re: Another 5 year hose replacment question

by Rob Seaton » 10 years ago

Rob Seaton

3 1.32k 251

just for debate: why would the service life not start at the first flight?
within reason; sometimes it takes 20+ years to finish a kit aircraft....