Brent,

 

Your recommendations are always well founded but occasionally a wisp of overkill creeps in (uh, perhaps I could have chosen a different word).  You recently described an "experiment" where you wrapped some tube interconnecting turbo components and later found heat deterioration of the metal. You then conducted another experiment by constructing a replacement part and a shield.  I hope this new experiment achieves the desired result.  Did you log these changes and the fly off tests?  Did you have an FAA inspector approve these experiments?  I have two old crumpled fifties laying around........... 

 

Anyway, I laud you for "experimenting" as many of us have done and especially for relating your experiences so that others may learn from them. 

 

Looking at the landing gear system on a 320/360 is an interesting  exercise in risk analysis.  I learned abut risk analysis when I was relatively young since in those days my mother would just send me out of the house with instructions to return before dark.  Of course, sometimes things didn't work out - things like my bed sheet parachute or the feet-to-ground braking system tried in an orange crate kid powered car. 

 

Back to the gear.  If a hydraulic line fails one is forced to use the "emergency" gear drop procedure with an outcome no worse than perhaps sitting in a pool of mil-spec fluid (approved by OSHA for short periods of time).  One should regularly test this system but I think that concept is backwards.  One should always use the gear drop method on landing, relying on the hydraulics only as a backup.  This technique verifies operations and keeps the pilot more alert on approach to landing (Maybe LOBO will pick up on this). 

 

Oh well, airworthiness determination is the responsibility of the pilot, the Certified Repairman, an A&P who probably never saw a Lancair before or, occasionally, a trial judge.  Drat, now there is some risk - a judge. 

 

My analysis shows that the person with a grip on the stick sits at the top of the flight risk pyramid. 

 

Now placing a strip of Rescue Tape over my mouth,

 

Scott     

 

George writes: <<< <>I decided to replace a few hoses just to get back in the business of building again and the attached picture is an example of one hose I produced.  I am not going to send my hoses off to Sacramento Sky Ranch for re-make, as a couple responders so sternly suggested.  I'm a homebuilder thank you very much, and I will make my own hoses.  I bought the hose and couplings from A/C Spruce.  >>>>

Why didn't you make the hose and fittings too? (I know, sarcasm is a low form of humor.) The reasons to use the Stratoflex 124 with integral firesleeve and crimped fittings include:

• Unlimited life, you only replace on condition.
• Inert liner. The teflon liner has the best chemical resistance, better than any rubber.
• Better fitting retention. The hose will fail before the crimp.
• Integral fire sleeve won't absorb oil or fuel.
• Lighter than rubber hose with fire sleeve.
• Factory pressure tested, cleaned and certified.

I want the safest components in my airplane. Did you pressure test your hose to 1.5X rated pressure and the flush the hose to remove the factory release agent? The release agent is usually a fine powder that is very abrasive to hydraulic components. Seals don't wear out because they are rubbing on smooth clean metal. They wear out because of contamination.

George also writes: <<<There is nothing to suggest to me that my airplane is not airworthy, as Brent Ragan would suggest.  If that were true it should have been un-airworthy at the first sign of a deteriorated hose covering, which I began noticing some months ago. >>>>

That IS true. Your plane was un-airworthy at the first sign of deterioration and I believe that if a Fed ramp checked your plane and saw that line they could ground you on the spot. What I think or even what you think is not important. It is how the FAA interprets the regulations that is important.

Here is my offer, show one of the hoses removed from your AC with the Rescue Tape to you local FAA inspector, have him sign a statement that the hose is just fine for your landing gear and send it to me. I'll send you a crisp $100 bill and a written apology.

Manufacturer's produce products to specifications or standards. If, in the course of service, the product fall outside the limits of that specification or standard then it ceases to be the product.

I want to see you get to 2,000 hours. I have participated in too many accident investigations. I don't even want to hear about another one. I am very pleased you decided to replace those hoses.

Regards
Brent Regan