Exhibit 12.1

TRANSDIGM GROUP INCORPORATED

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(Dollars in Thousands)

	Fiscal Years Ended September 30,										Twenty-Six Week Period Ended
	2012		2011		2010		2009		2008		March 30 2013		March 31 2012
Earnings:
Total earnings from continuing operations		324,969		152,225		163,445		162,902		133,126		142,107		146,657
Income tax provision		162,900		77,200		87,390		88,100		73,476		67,600		74,475
Pre Tax Earnings		487,869		229,425		250,835		251,002		206,602		209,707		221,132
Fixed charges:
Interest charges		211,906		185,256		112,234		84,398		92,677		126,970		101,361
Interest factor of operating rents (1)		2,602		1,959		1,398		1,095		1,052		1,442		1,139
Total fixed charges		214,508		187,215		113,632		85,493		93,729		128,412		102,500
Earnings as adjusted		702,377		416,640		364,467		336,495		300,331		338,119		323,632
Ratio of earnings to fixed charges		3.3		2.2		3.2		3.9		3.2		2.6		3.2

(1) For purposes of computing the ratio of earnings to fixed charges, earnings consist of earnings before income taxes plus fixed charges. Fixed charges consists of interest expense, amortization of debt issue costs and the portion (approximately 33%) of rental expense that management believes is representative of the interest component of rental expense.