Annual report pursuant to Section 13 and 15(d)

Intangible Assets

Intangible Assets

12 Months Ended

Mar. 31, 2015

5. Intangible Assets

Intangible assets consisted of the following (in thousands):

	March 31, 2015
	Weighted Average Amortization Period	Intangible Assets, Gross		Accumulated Amortization		Intangible Assets, Net
Manufacturing license	17 years	$	3,700	$	3,585	$	115
Technology	10 years		2,240		1,157		1,083
Parts and service customer relationships	5 years		1,080		1,080		—
TA100 customer relationships	2 years		617		617		—
Backlog	Various		490		351		139
Trade name	1.2 years		69		69		—

Total		$	8,196	$	6,859	$	1,337

	March 31, 2014
	Weighted Average Amortization Period	Intangible Assets, Gross		Accumulated Amortization		Intangible Assets, Net
Manufacturing license	17 years	$	3,700	$	3,536	$	164
Technology	10 years		2,240		933		1,307
Parts and service customer relationships	5 years		1,080		900		180
TA100 customer relationships	2 years		617		617		—
Backlog	Various		490		351		139
Trade name	1.2 years		69		69		—

Total		$	8,196	$	6,406	$	1,790

Amortization expense for the intangible assets was $0.5 million for each of the years ended March 31, 2015, 2014 and 2013.

Expected future amortization expense of intangible assets as of March 31, 2015 is as follows (in thousands):

Year Ending March 31,	Amortization Expense
2016	$	332
2017		352
2018		242
2019		224
2020		187
Thereafter		—

Total expected future amortization	$	1,337

The manufacturing license provides the Company with the ability to manufacture recuperator cores previously purchased from Solar Turbines Incorporated ("Solar"). The Company is required to pay a per-unit royalty fee over a seventeen-year period for cores manufactured and sold by the Company using the technology. Royalties of approximately $71,100, $83,000, and $76,700 were earned by Solar for the years ended March 31, 2015, 2014 and 2013, respectively. Earned royalties of approximately $19,300 and $20,700 were unpaid as of March 31, 2015 and 2014, respectively, and are included in accrued expenses in the accompanying balance sheets.