Weight and Balance amendment requirements

[hangarline]

But if the work is done at an AMO they are required to update the W&B if the airplane is commercial or private.

Absolutely, however not all private owners choose to get their maintenance done at an AMO because of...you guessed it, the extra rate per hour that is charged. And the extra rate that is charged is usually needed to cover things that are required because of regulation.

And again, I understand that not all owners fit in that category, I've just seen enough to get the broad strokes. The ones that do get their maintenance done at a good AMO will understand.

[boeingboy]

I tried finding the original equipment weight and balance information for mine but couldn't find it. It's a 1961 150A model, and there was very limited information provided in both the AMM and the POH. My POH/Owners Manual is only 64 pages, and is very basic. I found a 1977 150M POH online, and its almost 200 pages with a lot more information, including the original equipment weight and balance list, which mine lacks.

My W/B Report Equipment List only includes equipment that has been installed as mods/STCs to the original aircraft configuration.
I weighed the speaker, measured the arm, and entered it as "removed" item in the W/B Report amendment.

No Problem - what you did was fine. I have a 1962 B model and I happen to have the factory delivery sheet still...which showed the options and their weight and moments.

[Pratt Punk]

AC 43.13-1B CHG 1
"c. Negligible Weight Change is any change of one pound or less for aircraft whose weight empty is less than 5,000 pounds; two pounds or less for aircraft whose weight empty is more than 5,000 and 50,000 pounds; and five pounds or less for aircraft whose weight empty is more than 50,000 pounds.
Negligible c. g. change is any change of less than 0.05% MAC for fixed wing aircraft, 0.2 percent of the maximum allowable c. g. range for rotary wing aircraft."