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Thanks for the reply Matt, but maybe I'm not reading something correctly. I see where you can change the oil filter or strainer, where you can inspect a magnetic chip detector, and top off hydraulic oil but I still don't see where you can top off the engine oil.

I was just looking at the Topcat site ( http://www.topcatschool.com/ ), it looks like it is well worth the money.

[color:"blue"] "(6) Lubrication not requiring disassembly other than removal of nonstructural items such as cover plates, cowlings, and fairings." [/color]

What is adding oil if not lubrication?

Thanks, I thought that might be it. It sounds like I might need to remove my quick drain and buy a magnetic plug. It seems kind of odd that you can remove and replace the filter, add oil, but not drain the oil.

Am I right in assuming that I need to do that in order to legally change my oil and filter?

As some of your might remember, Rick Hestilow (TOPCAT Schools), was one of our seminar speakers a couple of years ago in Clinton. He is a great guy and very willing to help answer questions and help wherever needed.

No, Eric, you don't need to buy a magnetic chip detector. Most chip detectors in small aircraft merely replace and are in affect the drain plug. It's understood that if you can service a chip detector, you can service a drain plug.

I understand why you're looking for a literal interpretation that specifically states exactly what you can and cannot do, but the regs apply to most general aviation aircraft flown for pleasure such as ours, and therefore are more general rather than that specific in nature. You may change the oil and filter on your aircraft in it's existing configuration, and you can sign it off in the logs. I can only recommend that you do the first one under direct supervision, sign it off yourself, and have your mechanic co-sign your entry documenting his instruction and approval.

Thank you Carl. I did my last oil change myself and entered it in the log when I should have double checked the legality first (a local A&P told me it was ok before I did it). I know how the government can be, so the definitions of preventative maintenance in part 43 that I saw here made me a bit nervous.

That STC for Topcat still looks like a winner. Has anyone here actually gone through with it?

I talked to Rick Hestilow (for more than an hour!) a couple days ago. His TOPCAT program is on indefinite hold because of several issues, not the least of which is that he has no time because of a big multiyear project at the school where he teaches.

He didn't renew the lease on his training hangar and so will need to get approval from the FAA when/if he gets a new facility.

He said interest in the program was lower than he expected, but provided an easy explanation: As it is now, the STC requires that the student actually /do/ the maintenance tasks on /their/ airplanes as part of the class. That is, you have to pull and reinstall the starter, alternator, yada yada yada. Kind of pointless and risky if they aren't broken (stripped stud anyone?).

Another downside is that you'd have to fly your plane to Dallas - easy for surrounding states, but who wants to fly from Seattle to Dallas just to tear the plane apart for a class?

So he got some sort of preliminary approval to conduct the classes using 'training aids' (a stand-mounted engine, for example). I got the impression this would be a big investment.

The bottom line is that the TOPCAT enables owners to legally do many things they've done all along (on the sly). Generally, I'd have no problem replacing a starter illegally. The problem is, I couldn't put it in the logs and it could raise flags at annual time or with a future buyer. A lot of guys that change their own oil don't log it because they mistakenly believe they aren't allowed to do it. Try selling a plane that shows no oil changes in the last 500 hours!

An interesting sidenote is that TOPCAT is the first STC in history that modifies the owner, not the airplane. Once the STC is issued, the owner can work on any 150/152 that he is an owner (or partial owner) of, even after selling the original STC'd plane.

Okay, Rick Hestilow just emailed me. In addition to the Appendix 'A' work, the STC allows C150/152/172 owners to perform the following:

List of items included on TOPCAT Primary Category STC (STC SA09643SA, Rev. 1 & STC SA10114SC) for Cessna Model 150/152 and 172 Series aircraft

1. Replacement of flexible air ducting.
2. Replacement of static discharge wicks.
3. Replacement of fuel quick drains and filter cap gaskets and seals.
4. Replacement of Hour/Hobbs meter.
5. Replacement of brake pads, disc brakes.
6. Replacement of propellers.
7. Performance of engine cylinder compression check.
8. Replacement of engine accessory belts.
9. Engine oil change.
10. Replacement of navigation and communications radios where alterations to electrical circuitry are not required.
11. Removal of exhaust manifolds for gasket replacement as long as removal of other components is not required.
12. Replacement of starters.
13. Replacement of alternators.
14. Replacement of generators.
15. Replacement of vacuum pumps.
16. Fabrication/replacement of ? -inch diameter of less hard lines, regardless of their use (i.e., fuel, electrical, hydraulic, vent, vacuum, etc.).
17. Check control cable condition and tension (rigging or adjustment is not permissible).
18. Windshield scratch removal.
19. Sheet metal repair of aircraft skin damage of less than 2 inches.
20. Bleeding of brake system.
21. Replacement of engine rocker box cover and rocker box cover gaskets.
22. Replacement of engine and vacuum system air filters.
23. Service and or replacement of shimmy damper.
24. Lubrication and or replacement of the tachometer cable.
25. Replacement of the voltage regulator.
26. Removal or installation of the approved wheel pants with appropriate weight and balance computations and changes in the aircraft?s weight and balance records and the aircraft?s equipment list.
27. Cleaning the air / oil separator when installed.
28. Installation of approved oil quick drains and their replacement.


That's a whole buncha gas you can buy with those labor savings!

Why is engine oil change listed? Is this a gray area and we really aren't supposed to be doing it?

It's not really a grey area. You can do your oil as described earlier. This STC was written to make it more clear - because if it wasn't on this list, you'd still be in oil change limbo (even with the STC).

Side note:

Just saw this as part of an airplane ad (for a homebuilt). Tell me this doesn't sound like a propstrike:


Engine / Prop
Lyc. 0-320-150 hp, with about 300 hrs since complete overhaul but about 35hrs since rebuild with a new crank. (I chose to keep it at 150 hp because of the impending loss of Av Gas). Sensenich metal prop, approx 35hrs since new.