Is oil counted weight?

[Jim Hann]

To throw a little more mud on the subject. Just weighed my Pacer. The form I used contains the EMPTY WEIGHT and the BASIC EMPTY WEIGHT along with the AIRCRAFT AS WEIGHED number. Because we had no good way to drain the airplane (i.e. I'm not throwing 20 gallons of gas away) we topped it off, verified the capacity with the dipstick, and weighed it that way. I also did not have full oil, so that was mathematically corrected also.

Everybody confused now?

Oh, and the FAA does define BASIC EMPTY WEIGHT in their Weight and Balance Handbook FAA H-8083-1A and EMPTY WEIGHT and you'll find that the water just got a little muddier.

Well, I don't know where to start but here goes. There is no CAR 23 certification rules. I think what you mean is CAR Part 3, which was the certification regs for light planes during CAB days. From the CAR Part 3, Subpart B regulations for "empty weight" (not "standard empty weight" or "basic empty weight" because those are not regulatory terms) it states:

§ 3.73 Empty weight. The empty weight and corresponding center of gravity location shall include all fixed ballast, the unusable fuel supply (see § 3.437), undrainable oil, full engine coolant, and hydraulic fluid.

So that means no oil except residual oil.

Under Part 23, full oil is included in the empty weight. The applicable regulation is:

§23.29 Empty weight and corresponding center of gravity.

(a) The empty weight and corresponding center of gravity must be determined by weighing the airplane with—

(1) Fixed ballast;

(2) Unusable fuel determined under §23.959; and

(3) Full operating fluids, including—

(i) Oil;

(ii) Hydraulic fluid;

Hopefully we are in agreement now when oil is and is not included in empty weight.

In CAR 3 airplanes, manufacturers invented a term called "Basic Empty Weight" (or equivalent) which they published in the pilot handbook or owner manual to facilitate weight and balance computations for pilots. The BEW includes full engine oil, but don't confuse that with the FAA term "Aircraft Empty Weight." BEW is not a regulatory term.

The diagram you pasted above (#16) shows how to get "empty weight" when weighing the aircraft with full oil. They use a complicated mathematical operation called "subtraction" where the weight of the oil is subtracted from the scale weight to get empty weight. Empty weight is what goes on the Aircraft Weight and Balance Report.

[Marc Zeitlin]

I also did not have full oil, so that was mathematically corrected also.

All fine.

Oh, and the FAA does define BASIC EMPTY WEIGHT in their Weight and Balance Handbook FAA H-8083-1A and EMPTY WEIGHT and you'll find that the water just got a little muddier.

No, not really. Marty Mayes is absolutely correct here. Both 14 CFR parts 23.29 and 25.29 (for airplanes) and 27.29 and 29.29 (for helicopters) are explicit in stating that the empty weight includes full operating fluids, of which oil is one.

With respect to H-8083-1A, page 3-2 states, under the "Oil" section:

"The empty weight for aircraft certificated under the CAR,part 3 does not include the engine lubricating oil. Theoil must either be drained before the aircraft is weighed,or its weight must be subtracted from the scale readingsto determine the empty weight. To weigh an aircraft thatdoes not include the engine lubricating oil as part of theempty weight, place it in level flight attitude, then open thedrain valves and allow all of the oil that is able, to drainout. Any remaining is undrainable oil, and is part of theempty weight. Aircraft certificated under 14 CFR parts23 and 25 include full oil as part of the empty weight."

The last sentence matches up exactly with the language in parts 23 and 25, so there is no muddiness at all. It is clear that the current incarnation of the FAA expects that certificated aircraft and helicopters certificated under parts 23, 25, 27 or 29 include all operating fluids in their empty weight. While there is no such definition for experimental aircraft, the logic of the position is clear - if the thing is ALWAYS going to be in the plane when it's flying, then it should be included in the empty weight.

Seems like a big conversation over something that's particularly well defined in the regs...

[Mike M]

....the logic of the position is clear - if the thing is ALWAYS going to be in the plane when it's flying, then it should be included in the empty weight...

and the orange juice just came out my nose! full oil is always going to be in the airplane? show of hands here, how many Lycoming flyers load it to the top of the dipstick for every flight and always find it there the next morning? did it evaporate after it was parked? maybe no Continental cub engines in FAAland consume oil in flight, but Textron publishes an oil consumption chart. probably because they expect the oil level to change during operation. oh, wait, so does Continental? well golllll-eeee.

Marc, thanks for the laugh. i know what you meant, and you're right. it just hit me funny. You and Marty are trying to use common sense and FAA documents to bed this down. i'd tried to do that earlier by encouraging people to use the pubs for the type aircraft they were working with. while the topic's certainly beyond debatable using y'alls references plus normal reading comprehension - and the rules trump common sense - i'm guessing the debate will percolate .... oops, coffee's ready, gotta go

[Jazzenjohn]

I've started to fly the Gyro Marty. Had a little problem with the battery dying on me from a blown charging circuit fuse. I've since set it up so there is a backup pulse fuel pump and I have it set up so the alternator powers the CDI circuit so if the battery completely fails the engine will still run. I have run the engine and pulled the electric fuel pump fuse and it continues to run normally, I also pulled the battery and it also runs with the battery disconnected. I'm planning on taking it to Mentone on Monday.

[martymayes]

John, that's great. I looked up the dates for Mentone yesterday and if I get a chance I'll ride my motorcycle down.