A private pilot oral exam guide I'm reading asks a basic question about an issue I had taken for granted:

You have just completed the first leg of a long cross-country and notice that the oil level is approaching the one quart low mark. As a private pilot, can you add the quart of oil yourself or is a mechanic required? (See 14 CFR Part 43)

Clearly this must be preventative maintenance? No. 14 CFR Part 43 Appendix A does not explicitly list adding oil as preventative maintenance.

Searching online I found a lot of forum posts discussing this issue, some suggesting it is "obviously" preventative maintenance per the definition, but 14 CFR Part 1 does not define preventative maintenance, and others suggesting it isn't maintenance, it's servicing, but this isn't defined either.

How does this work if you're a student pilot on a solo cross country? If you shut the engine off and check the oil, are you stuck if the oil is low?

The best answer I can find is adding oil is not "maintenance" or "servicing," it is Normal Procedure per the Pilot Operating Handbook / Information Manual. The Cessna 172S POH as part of the preflight check on page 4-10 states:

Engine Oil Dipstick/Filler Cap -- CHECK oil level, the check dipstick/filler cap SECURE. Do not operate with less than five quarts. Fill to eight quarts for extended flight.

The POH is a little ambiguous how much oil to add, but it clearly states the pilot executing this procedure should add oil.

I believe this how a student pilot can add oil to a plane, or at least a Cessna 172S. Is this correct or is there a better explanation?

  • 1
    $\begingroup$ Beides the discussion if this is maintenance or not, I don't think the question would address trainees, but assume you passed the license and ask behavior in that case.otherwise it would ask for "can a no licensed guest top up lubricants" or such? $\endgroup$ – eckes Jul 6 at 17:29
  • $\begingroup$ [student pilot on a solo cross country] Is that a thing? Am I ignorant in my impression that no student is allowed to fly solo? Or is it understood that this always means "solo with instructor" and I'm the only one who doesn't know that? :,) $\endgroup$ – zedmelon Jul 7 at 13:56
  • 2
    $\begingroup$ @zedmelon At least in the USA, students are required to do actual solo (by themselves) cross country time. The flight planning is under instructor supervision of course, but the student must make the flight alone. $\endgroup$ – Brian Knoblauch Jul 7 at 14:42
  • $\begingroup$ @BrianKnoblauch: wow, never would've guessed (I'm more of an AviationSE lurker/enthusiast than knowledgeable resource). No doubt a student's solo flight is near the end of training--and no doubt parallels between pilot's license and driver's license are limited at best. That's gotta be such a kickass thrill! Thanks for the clarification. $\endgroup$ – zedmelon Jul 8 at 19:05

The FAA doesn't consider adding oil to be maintenance. The Hochberg (2016) interpretation says:

The subject of adding oil is often debated; however, we note that it is not an item included in part 43, appendix A, paragraph (c), which lists items the FAA considers to be preventive maintenance.

Also see the FAA's Flight Standards Information Management System, under Elements of Maintenance (emphasis mine):

In broad terms, it has been generally upheld that basic servicing tasks, such as fueling and adding oil, are neither maintenance nor preventive maintenance. But even that has some caveats. When adding oil requires a precise sequence of steps or partial disassembly to gain access, then that would be considered a maintenance activity. Adding oil to an oleo strut for example, would be a maintenance activity, whereas adding a quart of oil to a GA aircraft would not.

Since adding oil isn't maintenance - at least not in a simple GA aircraft - part 43 is irrelevant and there's no requirement to have any type of certificate to be allowed to add it.

| improve this answer | |
  • 3
    $\begingroup$ The Hochberg memo clearly states, "None of the tasks you referenced would be required by§ 43.9(a) to be entered in the maintenance records of the aircraft because, under the circumstances you described, they are neither maintenance nor preventive maintenance... The subject of adding oil is often debated; however, we note that it is not an item included in part 43, appendix A, paragraph (c), which lists items the FAA considers to be preventive maintenance." This is the clearest answer here--changing the oil is not preventative maintenance. Thanks!! $\endgroup$ – moof2k Jul 6 at 2:45

The FAA allows pilots to do maintenance themselves. It’s outlined in the following doc from the FAA as well as the full regulation here. I would say engine oil falls under:

  1. Lubrication not requiring disassembly other than removal of nonstructural items such as cover plates, cowlings, and fairings.
| improve this answer | |
  • 3
    $\begingroup$ Ah, but this is the crux of my question. If adding oil is preventative maintenance, then you must hold at least a private pilot certificate in order to add oil. Which would mean a student pilot cannot add oil to an airplane. $\endgroup$ – moof2k Jul 6 at 2:40
  • $\begingroup$ @moof2k: As some point the PTC's authority will kick in. $\endgroup$ – Joshua Jul 6 at 23:30
  • 1
    $\begingroup$ @moof2k A student pilot can perform preventive maintenance (43.3(g)) but you still need a private pilot to approve the return to service afterwards (43.7(f)). $\endgroup$ – Pondlife Jul 7 at 21:40
  • $\begingroup$ Thanks @Pondlife great find. So for example a student pilot could replace a landing light so long as a private pilot approves their work afterwards. A student pilot could not replace a landing light while out on a cross country solo. $\endgroup$ – moof2k Jul 18 at 14:24

I can't find a reference to link, but in the transport world, adding oil comes under the category of "replenishment", and is the same as adding fuel or topping off a reservoir that is crew-accessible.

Many corporate aircraft have oil replenishment systems for servicing engine oil, intended to be usable by the flight crew. On the CRJ regional airliners and Challenger corporate jets, the system has an oil tank and pumping setup in the aft equipment bay allowing the engines to be topped up by opening the belly hatch and standing in the opening to work the system.

Although flight crews can use the system, the operator management may discourage its use, or the crews themselves may prefer to get mechanics to do it (fear of getting uniform dirty, or risk of messing up the procedure, but in the corporate world you will find yourself having to do that sort of thing because you are in the middle or nowhere with no help available).

As part of your checkout for the 172, instruction on when and how of adding oil, and the operator's policies on replenishment, should be included. The POH says between 5 and 8 quarts, so you're good to depart with anywhere between 5 and 8. The engine will run fine on as little as 2 quarts (that's the minimum safe quantity in the sump to prevent un-porting during maneuvering - plus another half a quart in the oil lines and cooler, and the rest of the oil is essentially acting as a heat sink) and as long as the temperatures are in limits, in the short run the engine doesn't care how much oil is on board as long as the pickup in the sump doesn't un-port (long term is another matter).

It's useful to know the engine's oil consumption to be able to anticipate how much is enough for a trip. A lot of owners find the 0-320 tends to dump oil out the breather above 6 or 7 qts (the old O-290/O-235 family was much worse for this due to its breather outlet location), so an operator may tell you not to fill above 6 or 7 qts (If the engine burns a qt in 10 hours, that's at least 2 refuelings before you get to minimum oil even if you dispatch at 6, and the engine won't actually blow up on you unless you get down below 2, so you effectively can't ruin an engine with normal oil consumption even if you dispatch with 5 on board and go on a maximum range trip).

| improve this answer | |
  • $\begingroup$ bring on the electric plane! $\endgroup$ – Cloud Jul 6 at 9:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.