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 Periods Ended
	2010		2009		2008		2007		2006		April 2, 2011		April 3, 2010
Earnings:
Total earnings		163,445		162,902		133,126		88,645		25,117		48,459		68,804
Income tax provision		87,390		88,100		73,476		53,426		16,318		75,670		38,780
Pre Tax Earnings		250,835		251,002		206,602		142,071		41,435		124,129		107,584
Fixed charges:
Interest charges		112,234		84,398		92,677		91,767		76,732		86,693		56,928
Interest factor of operating rents		1,398		1,095		1,052		931		698		949		683
Total fixed charges		113,632		85,493		93,729		92,698		77,430		87,642		57,611
Earnings as adjusted		364,467		336,495		300,331		234,769		118,865		211,771		165,195
Ratio of earnings to fixed charges		3.2		3.9		3.2		2.5		1.5		2.4		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.