Weight and balance info

[woodmanrog]

When you weigh your plane, do you weigh it with or without oil in the crankcase. The FAR's say without (unless) you can't drain it. Since no most homebuilts require oil to fly, it would make sense to weigh the oil as it is always in the plane as is normal equipment. Just thought I would query feedback from all the really experienced builders.
Woodman
By the weigh,LOL, we included the oil in our W&B calculations. 1130 lbs, 0 fuel.

[AltonD]

include the oil.

Was your weight without paint? my paint added 20 pounds.

[Walt]

According to FAA-Weight and Balance Handbook:

FAA-H-8083-1A

Oil
The empty weight for aircraft certificated under the CAR,
part 3 does not include the engine lubricating oil. The
oil must either be drained before the aircraft is weighed,
or its weight must be subtracted from the scale readings
to determine the empty weight. To weigh an aircraft that
does not include the engine lubricating oil as part of the
empty weight, place it in level flight attitude, then open the
drain valves and allow all of the oil that is able, to drain
out. Any remaining is undrainable oil, and is part of the
empty weight. Aircraft certificated under 14 CFR parts
23 and 25 include full oil as part of the empty weight. If
it is impractical to drain the oil, the reservoir can be filled
to the specified level and the weight of the oil computed
at 7.5 pounds per gallon. Then its weight and moment are
subtracted from the weight and moment of the aircraft as
weighed. The amount and arm of the undrainable oil are
found in NOTE 1 of the TCDS, and this must be added to
the empty weight.

The CAR rules are no longer current, W&B is now done per 14 CFR part 23.

[woodmanrog]

We are pretty much on the same page. In answer to Alton, yes the paint is on the plane.
Roger

[cfiidon]

Walt has it right.

You used to be the initial weight and balance was calculated without oil, and that was called "licensed empty weight". The standard now is to do it with oil and call it "basic empty weight".

Doesn't really matter as long as you know which is which and how you calculate the resultant weight and balance.

Don

[tx_jayhawk]

Does anyone know the standard moment arm (datum) that it used for the oil on the RV-7A with 0-360? I did not initially include oil in teh W&B, and I am wondering if I can just add it (and the moment) to the basic empty weight.

Also, is aircraft empty weight considered with zero fuel, or zero usable fuel? If you must get all fuel out of the tanks, I assume you need to use the tank drains?

Thanks,
Scott
7A

[PCHunt]

Part 23 > Section 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; and

(iii) Other fluids required for normal operation of airplane systems, except potable water, lavatory precharge water, and water intended for injection in the engines.

(b) The condition of the airplane at the time of determining empty weight must be one that is well defined and can be easily repeated.

[alpinelakespilot2000]

So, if oil should be included in empty weight, do I use the full oil capacity of the engine (8 qts for my 0-320) or do I use what i will consider full for normal operations (~ 6 qts)?

(I've already done my W&B with 8 qts but, assuming that anything over about 6 qts is going to get blown out pretty fast anyway, using 8 for W&B seems kind of pointless.)

[Greg Arehart]

Steve,

See iii above. My interpretation would be to use the fluids that are "normally" in the airplane, thus if you consider 6 qts "full" or "normal", I would use that in my W&B. My opinion only of course. Either way, I suspect that an extra two quarts of oil won't really affect your envelope much.

Greg

[NickAir]

Many are with oil. I would add the oil based on seeing it done that way even on small certified planes. Fuel, passengers, luggage, and gear are all veriable. Oil is a constant weight value. Note: 15 pounds at the nose is equal to 1 pound on the tail with reegards to W&B.