Unless your aircraft has a Airworthiness Limitations Section which assigns a hose life-limit, they are all on-condition from the regulatory side. As to a "practical useful life" there are several guidance documents out there like this one which gives recommendations.
I might not have been clear on my original post. Of course I would never consider a 60 year old hose serviceable. I am working on a new-to-me aircraft and pulling all of the hoses preparing to replace any or all of them. All of your points are well taken and I have seen the leaching from the rubber on the inside of the hose that you mention. My question was very simply to get an opinion on a conservative useful hose life; I realize that some application of good judgment must be used in addition to reviewing the guidelines published by Parker (thanks Bell206). Thanks to all for the helpful feedback!
I'd like to think that, too, but finding such stuff suggests that either the owner is complacent, or doesn't know about it because his mechanic is complacent.
This is a good list Dan. My observation is that at least half of this list would apply to the problems with my aircraft (the several vintage planes that I own). My interpretation for "Complacency" is expanded to include laziness, incompetence, greed (do the minimum work to get paid the maximum $$ from the owner) and then simply a lack of integrity. Failing to replace a 60 year old hose is just one example. I know some really, really great mechanics so my comments are in no way meant to be a broad generalization. What troubles me is there seem to be a group of "shade tree" mechanics that gravitate to performing annual inspections on older, lower value aircraft, probably to meet the demand of owners who refuse to spend the money to properly maintain their planes. I can't begin to recall how many annual inspection logbook entries I have read that say nothing more than "serviced battery, performed landing gear retraction, repacked wheel bearings, verified ELT battery date, checked for AD compliance. I certify this aircraft to be in airworthy condition". Essentially they get paid to make a logbook entry. This is why I get deeply involved with the maintenance of my aircraft. This is why I ask a lot of questions on forums.
Tim, my first impression of your comment is that you are talking down to me assuming I am an uninformed aircraft owner, ignorant of the role of the mechanic and of the annual inspection process. I am not. My apology if I have misinterpreted you message. I merely stated facts based on my 47 years of aircraft ownership: some A&P mechanics (including those with IA) certify airworthiness without performing an adequate or proper inspection. Perhaps I could have better worded my comment in post #11. I am well aware that an “annual inspection” does not imply that the same person is automatically engaged to perform any maintenance or repair work as part of the inspection process. Furthermore I am aware of my responsibility as the owner/operator. No doubt many aircraft owners are grossly ignorant concerning all aspects of aircraft maintenance. However some owners may have extensive and intimate knowledge of their aircraft even if they don’t possess the A&P license. I value the knowledge gained on the various aviation forums and appreciate that you have taken time to review this thread, which I initiated. --Rob
I had come to the same conclusion as witmo on your post 11 but now see it was in error. But as to your "group of "shade tree" mechanics" comment, so long as there are "shade tree" aircraft owners around those type of mechanics will continue to prosper. It was the reason that I went strictly owner-assisted as I was tired of the "shade trees" out there. And from your recent comments, it appears you are one of those owners I would have assisted.
No question about it! Based on my observations bad mechanics represent a small percentage of the overall aircraft mechanic population. However the aircraft owner population... well that's a different story. There is a large group of dysfunctional people within our ranks. I appreciate your feedback for sure.
We uae PHT from Oklahoma for all of our hoses. Their service life is oil hoses 5 years or 1000 hrs. Teflon lined hoses 8 years or 1000 hrs. We routinely find hoses that are 25/ 35/ 45 years old and we replace them. Cessna 210's especially have hoses this age. Cessna service life is OH of the hydraulic power pack every 5 years. The last 15 C210's only one did NOT have the factory original power pack. That being said, so not to void the warranty on most power packs, and actuators they require hose replacement.