Mag timing check, for dumb guys

[Skymaster337B]

Do I need to remove the P-lead to do an external mag check? Does that require a "jumper" P-lead in it's place? Or can I just keep the P-lead installed and connect my timing box to the ignition grounding wire that comes off of it?

[Pete Somers]

You need to remove the P Lead and remove the cap from all the spark plugs for safety.

Pete

[Skymaster337B]

So, after I remove the P-lead, do I connect the timing tester wire to the removed P-lead? Or do I need to install a P-lead jumper cable into the magneto and then attach the timing tester wire to that jumper cable?

Originally Posted by Pete Somers

You need to remove the P Lead and remove the cap from all the spark plugs for safety.

Pete

[skymstr02]

Are you a licenced powerplant mechanic? If not, you should read FAR 43, and pay particular attention to appendix A.

I'll cut to the chase here. If you are a licenced mechanic, then you obviously do not have the required training to perform this function, and are not qualified to proceed any further, in accordance with FAR 65.

If you are not a licenced mechanic, this does not fall into the preventive maintenance scope of work, and you are not qualified to proceed any further, in accordance with FAR 43.

If you do proceed, your aircraft airworthiness certificate is invalid, read the small print in the center of the document:




A standard airworthiness certificate remains valid as long as the aircraft meets its approved type design, is in a condition for safe operation and maintenance, preventative maintenance, and alterations are performed in accordance with 14 CFR parts 21, 43, and 91.

[Skymaster337B]

Ok, I deserved that, base upon how I posted this. However, I think my timing box is broken, and I just wanted some reassurance that I'm not missing anything...short cuts or shop secrets.

Thanks

[skymstr02]

I apologize for being so harse, but I got burned by the FAA once after completing an annual inspection on a customers aircraft. The owner had performed undocumented maintenance, and since my name was the last in the book, I took the heat.

Touch the ground lead from your buzz box to one of the other leads, listen for a tone change and a light to either go on or off, depending on the type of box that you have. That will be the test for the unit.

[Skymaster337B]

Broken wires grounded it out...all is well now.

[Skymaster337B]

By the way, how did the FAA figure out that you were responsible for work that the owner did? And how do I protect myself from such FAA finger pointing?

[skymstr02]

Because my last annual release for flight was the last entry in the maintenance log.
Like I said, undocumented maintenance. I had a copy of my itemized work order that mirrored the log entry, and used that in my defense. The owner had installed some automotive accessories and got caught on a ramp check by an FAA inspector.
I have always argued that the log book entry is void (as far as airworthiness) when the airplane leaves the hangar. I can't state the the airplane will be airworthy next week, if the airplane is not in my control.

[Skymaster337B]

Sounds like you could fight that one...at your expense of course. The FAA's position is that an annual inspection is a visual inspection by nature and ensures conformity only on the day the IA signs it off. That means the owner/operator is responsible for airworthiness after the airplane leaves the IA's hangar. It sounds like that FAA inspector was a jackass.