Property and Equipment (Tables)

3 Months Ended

Mar. 31, 2018

Property and equipment are stated at cost. Depreciation is calculated using the straight-line method over estimated useful lives as follows:



	Useful Lives
Aircraft and components	10 to 20 years
Buildings	39 years
Building improvements	7 to 15 years
Computer equipment	2 to 6 years
Demonstration units	3 years
Furniture and office equipment	2 to 6 years
Leasehold improvements	Lesser of useful life or term of lease
Machinery and equipment	5 to 10 years
Tooling	3 years
Vehicles	5 years

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



	March 31, 2018			December 30, 2017
Building and building improvements	$	88,215		$	87,999
Machinery and equipment	49,842			47,556
Aircraft and vehicles	25,329			25,329
Land	23,762			23,762
Computer equipment	15,785			15,789
Leasehold improvements	15,649			15,326
Tooling	13,818			13,754
Furniture and office equipment	10,328			9,967
Demonstration units	491			486
Construction-in-progress (CIP)	6,994			6,365
Total property and equipment	250,213			246,333
Accumulated depreciation and amortization	(85,977		)	(82,237		)
Property and equipment, net	$	164,236		$	164,096