Exhibit 12.1

TRANSDIGM GROUP INCORPORATED

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(Dollars in Thousands)

	Fiscal Years Ended September 30,										Thirteen Week Period Ended
	2012		2011		2010		2009		2008		Dec 29 2012		Dec 31 2011
Earnings:
Total earnings		324,969		152,225		163,445		162,902		133,126		74,170		65,105
Income tax provision		162,900		77,200		87,390		88,100		73,476		35,800		31,100
Pre Tax Earnings		487,869		229,425		250,835		251,002		206,602		109,970		96,205
Fixed charges:
Interest charges		211,906		185,256		112,234		84,398		92,677		62,876		49,061
Interest factor of operating rents		2,602		1,959		1,398		1,095		1,052		713		539
Total fixed charges		214,508		187,215		113,632		85,493		93,729		63,589		49,600
Earnings as adjusted		702,377		416,640		364,467		336,495		300,331		173,559		145,805
Ratio of earnings to fixed charges		3.3		2.2		3.2		3.9		3.2		2.7		2.9

(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.