Mailing List lml@lancaironline.net Message #56883
From: Bill Wade <super_chipmunk@roadrunner.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Hydraulic hoses
Date: Thu, 09 Dec 2010 07:56:44 -0500
To: <lml@lancaironline.net>
  Originally, George was concerned and looking for advice (see below). He got advice.
 
  Apart from Scott Krueger, everyone advised him to replace the hoses. Scott confirmed what he wanted to do, but in his last post George is grumbling because other people disagree with his plan of action.
 
  Scott is correct in that the PIC has responsibility for confirming airworthiness prior to each flight. He and George both have Repairman's certificates for their planes so they can maintain them as they see fit. They are both demonstrating their judgement. I think it's bogus to claim that anyone should be prepared for a failure without employing preventive maintenance to avoid having the situation occur. That means replacing items *before* they fail, even if it may be premature.
 
  I personally don't understand what George and Scott think they are gaining by wrapping. George's plane is down and he has to do the same work as he would to replace the hoses. When it's all done he'll have the same old hoses, only disguised. There's no way to tell when they'll start leaking or burst, and whether the lining is deteriorating.
 
  I don't think bragging rights for the oldest hoses amounts to much. It may also indicate poor practices elsewhere.
 
   Airworthiness implies that the aircraft will be maintained so that systems are equal or better than they were when the certificate was granted. For example, duct tape may cover a puncture but it doesn't qualify as a fabric repair. If anything goes wrong and George harms others as a result he or his estate will have sole responsibility. I don't think the FAA or any insurance company would be sympathetic.  -Bill Wade
 
----- Original Message -----
Sent: Wednesday, October 20, 2010 2:36 PM
Subject: [LML] Hydraulic hoses

Very timely, for me, are recent postings regarding hydraulic hoses.
 
After 16 years, the outer rubber coating on my hoses is starting to crack and, on many of my hoses, is actually breaking off, revealing the white woven material.  I have been watching this occur with some concern.
 
The question is: Is this an immediate safety concern?  Is there increased chances of a hose failure, and if so, how big a concern is it.  In other words, should the airplane be immediately grounded until I fabricate new hoses? 
 
These questions are for an experienced hydraulics person, and not for emotional speculation by those seeking perfection.
 
George Shattuck
LNC2, 1350 flight hours
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