W&B - calculated with or without engine oil?

[N74DV]

From what I hear, aircraft certified after around 1978 are to have engine oil in the engine when weighing the aircraft for a W&B. Does this mean the a '46 BC12D is to be weighed without the engine oil to determine the empty weight & balance?

I looked at A-696 TCDS and didn't seem to find any specific notation of the weights and balance being calculated with or without engine oil.

[magman]

Re: W&B - calculated with or without engine oil?

Aircraft post 1978 MAY have useable engine oil included in the Empty Weight CG calculations.

Generally it is then referred to as " Basic Empty Weight".

Older aircraft such as a BC12D do not have useable engine oil in the EWCG.

Do not prevent you from having sample loading charts with oil in.

[magman]

Re: W&B - calculated with or without engine oil?

Aircraft post 1978 MAY have useable engine oil included in the Empty Weight CG calculations.

Generally it is then referred to as " Basic Empty Weight".

Older aircraft such as a BC12D do not have useable engine oil in the EWCG.

Do not prevent you from having sample loading charts with oil in.

[Guest]

Re: W&B - calculated with or without engine oil?

From what I hear, aircraft certified after around 1978 are to have engine oil in the engine when weighing the aircraft for a W&B. Does this mean the a '46 BC12D is to be weighed without the engine oil to determine the empty weight & balance?

I looked at A-696 TCDS and didn't seem to find any specific notation of the weights and balance being calculated with or without engine oil.

Hi DJ,

Check out the FAA's circular called "Weight and Balance Handbook" number FAA-H-8083-1A on page 3-2 you will find this;

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.

The TCDS gives the capacity and arm of the oil for your loaded calculations.

Dave

[jstall]

Re: W&B - calculated with or without engine oil?

From what I hear, aircraft certified after around 1978 are to have engine oil in the engine when weighing the aircraft for a W&B. Does this mean the a '46 BC12D is to be weighed without the engine oil to determine the empty weight & balance?

I looked at A-696 TCDS and didn't seem to find any specific notation of the weights and balance being calculated with or without engine oil.

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

Draining the Fuel
Drain fuel from the tanks in the manner specified by the
aircraft manufacturer. If there are no specific instructions,
drain the fuel until the fuel quantity gauges read empty
when the aircraft is in level-flight attitude. Any fuel
remaining in the system is considered residual, or unusable
fuel and is part of the aircraft empty weight.

Thus the aircraft empty weight is the airplane, its equipment, and all undrainable oil and fuel

[astjp2]

Re: W&B - calculated with or without engine oil?

Just note the oil in your weight and balance, if you fly with oil, how you load the airplane and where every weigh point is actually located are things that need to be measured. I weigh them with oil in because that is how the airplane flies. No matter how you configure the airplane, you can always calculate oil out. I have even weighed and airplane with full fuel and then with the fuel removed. its all about documenting...and measuring... you don't need to overthink this, you just need to know how much fuel and baggage and how much people need to weigh for a load schedule. The AC on weight and balance is good advice but you need to look at the big picture on what you need a weight and balance is for. Tim

[Hank Jarrett]

Re: W&B - calculated with or without engine oil?

Tim is right about this. What you really need is a legal W&B that is done correctly in accordance with the regulations. Then a second on with the oil in for the guy you can't convince that it isn't supposed to be there, then the REAL one with all the equipment you ALWAYS have in the plane so you just have to put in fuel, pilot, passenger and cargo with their weight and arm.
There is no sense arguing with an FAA rep on a ramp check. Just give him the one he wants and be sure you are within GW and CG limits.

Hank

[magman]

Re: W&B - calculated with or without engine oil?

My practice to two make up 2 EWCG Reports.

Wheel Fairings ON & Wheel Fairing OFF.

That way Fairings can go ON & OFF with no calculations.

I've seen too many aircraft that had "installed" 4 times

& "removed" 0!

[Hank Jarrett]

Re: W&B - calculated with or without engine oil?

What? You have never seen a Taylorcraft with 8 wheels?

Hank

Nine with the tail wheel.

[Guest]

Re: W&B - calculated with or without engine oil?

If you are using the EWCG range that is described in the TCDS like this or similar "When empty weight C.G. falls within the pertinent range, computation of critical fore and aft C.G. positions is unnecessary." to avoid making a loading schedule then you will want to have you EWCG calculated appropriately with or without oil depend on cert. basis so you match the calcs that the mfg. did to make that range.

EWCG's can be calculated so as pointed out earlier you can weigh the airplane anyway you want then make calculations to find EWCG.

Also check out AC43.13-1b chapter 10 it has full explanation of all this.

[Bird]

Re: W&B - calculated with or without engine oil?

I noticed that we are talking about two different things here-Empty weight and W&B. Just wanted to point this out.

[astjp2]

Re: W&B - calculated with or without engine oil?

The empty weight is the starting point for W&B from my perspective. Tim