5 year rubber replacement-true need?

Have you seen the oil lines and how they've hardened?   Best to keep the fliuds on the inside of the rubber...

 (Australia)

As I understand; If your aircraft is a factory built (ie non experimental), you must comply with Rotax advisory's.

If your aircraft is a kit/home built (experimental), you can make whatever decision you deem appropriate and accept the associated risks (which may include your deceased estate being sued for your wilful negligence) 

It’s a safety thing. How much do you value your safety.

An acquaintance of mine destroyed his aircraft in a forced landing after a hose failed in flight.  It's probably more cost effective to replace the rubber every 5 years even though it might last 8 years or more before it fails.  Rubber hoses are cheaper than buying a whole new aircraft. 

And can be recycled for use in ground based equipment, abrasion covers for hoses/cables, "stand-off's" when zip tying, etc