Note 6. Balance Sheet Components

Property and equipment, net consists of the following (in thousands):

 

Depreciation and amortization expense of Property and equipment for the years ended December 31, 2021 and 2020 was $12.1 million and $7.4 million, respectively. Vehicles and aircraft includes utility automobiles used at our various facilities and purchased aircraft to support Part 135 operations and training.

The intangible assets consist of the following:

 

Amortization expense related to intangible assets for the or the years ended December 31, 2021 and 2020 was $3.8 million and , respectively. As of December 31, 2021 the weighted-average amortization period of intangible assets was 3.57 years.

The following table presents the estimated future amortization expense of acquired amortizable intangible assets of December 31, 2021 (in thousands):

 

Prepaid expenses and other current assets consist of the following (in thousands):

 

Other assets consist of the following (in thousands):