Which system to record TTIS?

[skippydiesel]

Hi Bruce - As I said, I do not disagree with your oil change policy (I religiously follow the Rotax 912 reconmeded intervals & oil) but found it a little at odds with your comments on service intervals.

 

 

[skippydiesel]

On the subject of Rotax rubbers, I think this is a mandated thing and you have no choice about doing it.

 

Well you could choose to fly illegally, but I for one would not recommend that . But it would hurt to pay   exorbitant money to replace sound rubber hoses  years before they needed it.

 

How long do those discarded hoses last on the ground vehicles? Many years is my guess.

 

What if the risk of a hose replacement job exceeded the risk of running with an older but still sound hose? On my cars, I squeeze the hose and look for micro-cracking of the rubber surface  in the area where it is under tension from the squeeze deformation.  This is an " on condition" test.

 

There was a Jabiru which force-landed on the Stuart Highway. The owner had conscientiously replaced the hoses before his big trip. The new hose slowly vibrated up into a tapered zone and got shut off. That guy illustrated how reliability can be LESSENED by too much maintenance. The old hose would have been fine.

 

Bruce - "mandated" ?? -  only on factory built aircraft (does not apply to mine).

 

Yes, the preloved hoses last and last but as I am careful with how I purchase and pay, I find sticking to the Rotax interval, to be not expensive, reassuring and somehow satisfying.

 

 

I have 1985 Daihatsu Rocky 2.8 turbo diesel (purchased new) with well over 500,000 kms of hard work (towing) on the "clock" - I have never replace the coolant hoses in all that time. Never had a leak. Recent incident- young man "T boned"  me-  write off ! - purchased back from the insurer - as part of rebuild, am replacing all the rubbers for the first time. "On condition" replacement  is just fine for a land based vehicle/equipment , being maintained by someone who has a fair degree of knowledge & experience. I stress this is NOT something I would do or recommend for an aircraft .

 

From defective aging memory, I think I estimated a little time ago, on another "thread" that a major service, including all rubber replacement , on my 912 ULS/aircraft cost about $700 - not too bad in my opinion.