Transdigm 10-K 2004 FY Annual report

Exhibit 12.1

TRANSDIGM HOLDING COMPANY

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(Dollars in Thousands)

	Predecessor									July 23, 2003 Through Sept. 30, 2003			Year Ended September 30, 2004
	Fiscal Year Ended September 30,						October 1, 2002 Through July 22, 2003
	2000		2001		2002
Earnings:
Total earnings (loss)	$	10,779	$	14,358	$	30,629	$	(69,969	)	$	(2,788	)	$	29,610
Income tax provision (benefit)		7,972		9,386		16,804		(40,701	)		(2,275	)		16,433
Pre Tax Earnings (loss)		18,751		23,744		47,433		(110,670	)		(5,063	)		46,043
Fixed charges:
Interest charges		28,563		31,926		36,538		28,224			9,567			48,936
Interest factor of operating rents		323		365		419		408			163			455
Total fixed charges		28,886		32,291		36,957		28,632			9,730			49,391
Earnings as adjusted	$	47,637	$	56,035	$	84,390	$	(82,038	)	$	4,667		$	95,434
Ratio of earnings to fixed charges(1)		1.6		1.7		2.3		—			—			1.9

(1) For purposes of computing the ratio of earnings to fixed charges, earnings consist of earnings before income taxes plus fixed charges. Fixed charges consist of interest expense, amortization of debt issuance costs and the portion (approximately 33%) of rental expense that management believes is representative of the interest component of rental expense. Earnings were insufficient by $110,670 and $5,063 to cover fixed charges for the period October 1, 2002 through July 22, 2003 and the period July 23, 2003 through September 30, 2003, respectively.