A few weeks ago, I got an email from a gentleman who was overhauling an antique propeller. He needed to know what lubricant to use in the prop.
The company that manufactured the prop was no longer in business, so all he had was an obsolete spec. I told him I would see what I could find and get back to him.
I first went though my files and found the original spec, but could not find any replacement or document that stated that a particular lubricant replaced the original. I then hit the Internet and called several oil company information centers for a replacement. But no luck.
Next I started calling people I knew who worked in prop shops. The answers varied from “I don’t ever want to see one of those again” to “yes, I have heard of them and I think you use such and such fluid.”
The problem is that the fluids were very different and no one had any documentation that stated that the fluid was a replacement for the original qualified fluid.
After a bit more searching, I called the gentleman back and told him what I had found. I also related back the phone numbers of the people who had experience with these props and had agreed to talk to him.
This is what I call a gray area. What should a mechanic do? Do you tell the pilot that you can’t help him and he may have to let the plane sit, or do you use a product that has been used by others but does not have complete documentation?
If you ask a lawyer or FAA official, the answer is to let the plane sit. But most mechanics like to help people out and hate to see a beautiful old plane sit or be scrapped.
The problem with gray areas is that the legal system only sees things in black and white.
If this plane happened to be involved in an accident, a legal team will go over the history of the aircraft with a fine-tooth comb looking for any gray areas or things that are not completely documented. If they find that a non-qualified lubricant was used in the prop and there are no other major problem, they stop looking.
Then this amazing thing happens: Expert witnesses appear who know everything about this old prop. And they will testify — for a fee — that the use of this unqualified lubricant was definitely the cause of the accident.
Another gray area is compression testing. Most mechanics use a leak down type of compression gauge to determine the condition of each cylinder. This system works well and almost all bad cylinders will fail the test. The problem is that a significant number of good cylinders also fail the test.
Continental now has an alternate method of compliance if your engine fails the first test. Unfortunately, this test is more subjective and open to interpretation. So what happens if an engine fails one test and passes the other and subsequently has an engine failure? Back to the battle of the expert witnesses.
So what does a mechanic do? Unfortunately, a lot of mechanics are just getting out of the business. The other option is discussion and documentation. A mechanic needs to get a customer involved in the decision process whenever a gray area is encountered. Many times they will need to get an outside opinion, usually from a manufacturer’s rep or a real expert.
And then there is documentation. Most mechanics are in the business of fixing things, not doing a lot of paper work. But it is critical in these situations that you get not just an oral agreement, but also a signed written agreement as to the course of repairs and all of the test results that the decision was based on.
It is like going to the bathroom — the job isn’t complete until the paperwork is done.