Exhibit 12.1

TRANSDIGM GROUP INCORPORATED

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(Dollars in Thousands)

	Fiscal Years Ended September 30,										Thirty-Nine Week Period Ended
	2012		2011		2010		2009		2008		June 29, 2013		June 30, 2012
Earnings:
Total earnings from continuing operations		324,969		152,225		163,445		162,902		133,126		218,762		237,103
Income tax provision		162,900		77,200		87,390		88,100		73,476		105,200		114,500
Pre Tax Earnings		487,869		229,425		250,835		251,002		206,602		323,962		351,603
Fixed charges:
Interest charges		211,906		185,256		112,234		84,398		92,677		189,439		156,754
Interest factor of operating rents (1)		2,602		1,959		1,398		1,095		1,052		2,092		1,882
Total fixed charges		214,508		187,215		113,632		85,493		93,729		191,531		158,636
Earnings as adjusted		702,377		416,640		364,467		336,495		300,331		515,493		510,239
Ratio of earnings to fixed charges		3.3		2.2		3.2		3.9		3.2		2.7		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.