where do i input a sale of personal property?

This would be reported as an investment sale subject to capital gains.  If you sold the airplane for a profit, then you will be subject to capital gains tax.  If you sold it at a loss, then you cannot claim that loss because it was personal property.

Follow the instructions in the TurboTax help article below for guidance about where to go in the program to report the sale.  When you get to the drop-down box asking what type of item was sold, select 'personal item' and continue from there.  

Where do I enter the sale of a second home, an inherited home, or land on my 2024 taxes?
 

If the personal property was sold for the less than the original purchase price it is not reported on a tax return.

Otherwise you report the gain on the sale as an investment.  You will need to upgrade to the Premium online edition.

To enter an investment sale -

Click on Federal Taxes (Personal using Home and Business)
Click on Wages and Income (Personal Income using Home and Business)
Click on I'll choose what I work on (if shown)
Under Investment Income
On Stocks, Cryptocurrency, Mutual Funds, Bonds, Other, click the start or update button

Or enter investment sales in the Search box located in the upper right of the program screen. Click on Jump to investment sales

Using the online editions -

On the screen Did you have investment income in 2024? click on Yes

On the screen Let's import your tax info click on Enter a different way

On the screen OK, let's start with one investment type, select the Investment Type and Continue

On the screen Tell us more about this sale select Other and Continue

On the following screen select the type of investment sale on the dropdown What type of investment did you sell?

Continue with this section until it completes.