What are the precise requirements for an A&P (N-reg) component overhaul?

It’s worth pointing out that in the definition of overhaul in the regulation quoted by Michael above, post #24, there is nothing about bringing the component to any particular condition. The only phrase that addresses that issue for an overhaul says that the component must be “repaired as necessary”. With that in mind I suspect the regulatory difference between repair and overhaul is not what your average person would expect.

An operation documented in a logbook as repair could bring the component to a better condition than something documented as an overhaul. An A&P mechanic can either overhaul or repair an engine but the main difference is whether the engine is completely disassembled and inspected. The FAA regulation provides the framework for the defintion of an overhaul but does not dictate the exact work that the individual may choose after inspection and before reassembly, as long as all components are within service limits at reassembly.

Peter wrote:

In between the two positions above, you have lots of other bits… which may or may not need the MM.

Yep, and each and every A&P will have his own personal view on what he can or cannot do.

Is there a list somewhere?

Not that I’m aware of.

Peter wrote:

is there a legal difference between a Repair and an Overhaul, with these items? I know there is with engines… an Overhaul is IAW an “overhaul manual” and everything lesser is a Repair.

ABSOLUTLY !

Nothing ambiguous in the FAA FARS about this:

OVERHAUL is defined in 14 CFR 43.2(a):

“No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being overhauled unless-

(1) Using methods, techniques, and practices acceptable to the Administrator, it has been disassembled, cleaned, inspected, repaired as necessary, and reassembled; and

(2) It has been tested in accordance with approved standards and technical data, or in accordance with current standards and technical data acceptable to the Administrator, which have been developed and documented by the holder of the type certificate, supplemental type certificate, or a material, part, process, or appliance approval under part 21 of this chapter."

Peter wrote:

is quite ambiguous, in the use of the word “understands”.

Yep, FAA regs leave MUCH to interpretation.

So when I write “bang on this” what I really mean is one can spend DAYS debating on EXACTLY what the FAA reg meaning , only to wind up with the obvious: It means different things to different people

Peter wrote:

Now, on the topic of brushes… what privileges are needed to change motor brushes, where there is no repair or overhaul data available?

Peter – You can bang on this all day long if you like, but the FAA FARs are there and they are not going to change just because so & so said this or did that… In this case the relevant bit is FAR 65.81 – “General privileges and limitations.”, copied once more below for your perusal .

In this particular example (gear electro/hydro pump) I have indeed “Repaired” these units on numerous occasions on Cessna retracts. This is possible because there is sufficient information in the MM & IPC to satisfy FAR 65.81 .

I would never consider calling any of these Repairs “Overhauls” because the Overhaul Data is NOT in the MM and IPCs .

That said, many A&Ps and EASA Mechanics having been trained and experience working in Part 145 and/or REpair Station environments tend to shy away from “Field Repairs” such as the gear pump example.

• FAR 65.81 – “General privileges and limitations.”*

(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments), and may perform additional duties in accordance with §§65.85, 65.87, and 65.95.

However, he may not supervise the maintenance, preventive maintenance, or alteration of, or approve and return to service, any aircraft or appliance, or part thereof, for which he is rated unless he has satisfactorily performed the work concerned at an earlier date. If he has not so performed that work at an earlier date, he may show his ability to do it by performing it to the satisfaction of the Administrator or under the direct supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had previous experience in the specific operation concerned.

(b) A certificated mechanic may not exercise the privileges of his certificate and rating unless he understands the current instructions of the manufacturer, and the maintenance manuals, for the specific operation concerned

In practise I’ve never had an issue with repairs on the FAA system. For example, once the generator (originally an old tractor part – the ancient International Harvester tractor we use at the glider club I’m sure has the same dynamo) packed up on my old Cessna 140 the best part of 1000 miles from home. I found an old airport geezer and son A&P/IA outfit, and they overhauled my generator on the spot (including taking the armature to a commercial electrical machines repair shop) and made the appropriate logbook entries, and I was on my way. There was no handwringing over approved data. A generator (like a motor) is a pretty simple device. This is how it works in practise.

Peter, I believe an FAA A&P mechanic electric motor overhaul using commercial subcontractors is legal if the A&P has approved data for the materials and process used in the overhaul and is available in person to supervise the work. In those requirements it is no different than supervising me (an uncertificated ‘mechanic’) and signing off my work on the plane itself. In the case of the electric motor, I think it would be difficult to get the approved data… if (for example) you wanted to rewind/reinsulate the windings.

For engines, the overhaul data is more widely available and it is similarly legal for an A&P mechanic to supervise a commercial (e.g. airboat engine) machine shop in reworking engine parts, then sign off the engine overhaul himself. I know an A&P who overhauled the AEIO-540 on his certified N-registered Extra that way, quite a large engine, and a very nice job it was too.

I think if you dig deeply enough into any example of FAA regulations in aircraft maintenance, there are grey areas. FAA quite sensibly does not attempt to create a ‘perfect’ system and then force people to operate to the letter of that ‘perfect’ system. Instead they laid out a simple framework, let individuals and businesses figure out how they can best operate within the imperfect but clearly documented framework (in their own way) and then fix specific regulatory problems that through experience are shown (by evidence) to have led people into doing something that caused an accident. Hence FAA = Fix After Accident. It works well and efficiently in the real world even if it seems to make the rather less experienced EASA ‘geniuses’ nervous.