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Exhibit 12.1

TRANSDIGM GROUP INCORPORATED
COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
(Dollars in Thousands)

														Predecessor
				Twenty-Six Weeks Ended March 31 2007		Twenty-Six Weeks Ended April 1, 2006								July 23, 2002 Through Sept. 30, 2003			October 1, 2002 Through July 22, 2003
								Fiscal Years Ended September 30,												Fiscal Year Ended September 30, 2002
								2006		2005		2004
Earnings:
	Total earnings (loss)			$	41,849	$	23,258	$	25,117	$	34,687	$	13,622	$	(5,759	)	$	(69,969	)	$	30,629
	Income tax provision (credit)				24,743		14,499		16,318		22,627		6,682		(3,970	)		(40,701	)		16,804
		Pre Tax Earnings (loss)			66,592		37,757		41,435		57,314		20,304		(9,729	)		(110,670	)		47,433
Fixed charges:
	Interest charges				40,396		39,181		76,732		80,266		74,675		14,233			28,224			36,538
	Interest factor of operating rents(1)				363		349		698		635		452		163			408			419
			Total fixed charges		40,759		39,530		77,430		80,901		75,127		14,396			28,632			36,957
Earnings as adjusted				$	107,351	$	77,287	$	118,865	$	138,215	$	95,431	$	4,667		$	(82,038	)	$	84,390
Ratio of earnings to fixed charges					2.6		2.0		1.5		1.7		1.3		—	(2)		—	(2)		2.3

(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.

(2)

Earnings were insufficient by $110,670 and $9,729 to cover fixed charges for the period October 1, 2002 through July 22, 2003 and the period July 8, 2003 through September 30, 2003, respectively.

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TRANSDIGM GROUP INCORPORATED COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES (Dollars in Thousands)