UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the fiscal year ended September 30, 20112012

For the transition period from            to            

Commission File Number 001-32833

TransDigm Group Incorporated

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of incorporation or organization)

41-2101738

(I.R.S. Employer Identification No.)

(216) 706-2960

(Registrants’ telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  x    No  ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The aggregate market value of the voting and non-voting common stock held by non-affiliates of the registrant as of April 2, 2011,March 31, 2012, based upon the last sale price of such voting and non-voting common stock on that date, was $4,234,949,579.$5,540,323,145.

The number of shares outstanding of TransDigm Group Incorporated’s common stock, par value $.01 per share, was 50,344,43951,694,655 as of October 28, 2011.27, 2012.

Documents incorporated by reference: The registrant incorporates by reference in Part III hereof portions of its definitive Proxy Statement for its 20122013 Annual Meeting of Stockholders.

TABLE OF CONTENTS

Special Note Regarding Forward-Looking Statements

This report on Form 10-K contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and 27A of the Securities Act of 1933, as amended. Discussions containing such forward-looking statements may be found in Items 1,1A, 2, 3, 5 and 7 hereof and elsewhere within this Report generally. In addition, when used in this Report, the words “believes,” “anticipates,” “expects,” “should” and similar words or expressions are intended to identify forward-looking statements. Although the Company (as defined below) believes that its plans, intentions and expectations reflected in or suggested by such forward-looking statements are reasonable, such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements made in this Report. The more important of such risks and uncertainties are set forth under the caption “Risk Factors” and elsewhere in this Report. Many such factors are outside the control of the Company. Consequently, such forward-looking statements should be regarded solely as our current plans, estimates and beliefs. We do not undertake, and specifically decline any obligation, to publicly release the results of any revisions to these forward-looking statements that may be made to reflect any future events or circumstances after the date of such statements or to reflect the occurrence of anticipated or unanticipated events. All forward-looking statements attributable to the Company or persons acting on its behalf are expressly qualified in their entirety by these cautionary statements.

In this report, the term “TD Group” refers to TransDigm Group Incorporated, which holds all of the outstanding capital stock of TransDigm Inc. The terms “Company,” “TransDigm,” “we,” “us,” “our” and similar terms refer to TD Group, together with TransDigm Inc. and its direct and indirect subsidiaries. References to “fiscal year” mean the year ending or ended September 30. For example, “fiscal year 2011”2012” or “fiscal 2011”2012” means the period from October 1, 20102011 to September 30, 2011.2012.

PART I

The Company

TransDigm Inc. was formed in July 1993 in connection with the acquisition of certain businesses from IMO Industries Inc. TransDigm Group Incorporated (“TD Group”) was formed in July 2003 to facilitate the acquisition of TransDigm, Inc. In March 2006 and May 2007, certain stockholders of TD Group and certain members of our management sold shares of TD Group common stock in underwritten public offerings. TD Group did not offer any shares of common stock for sale in the offerings and TD Group did not receive any of the proceeds from the sale of shares by the selling stockholders. As a result of the initial public offering in 2006, TD Group’s common stock is publicly traded on the New York Stock Exchange under the ticker symbol “TDG.” As a result of the follow on offering in 2007, TD Group was no longer a “controlled company” for the purposes of the NYSE listing requirements.

On December 6, 2010, TransDigm Inc. completed the acquisition of McKechnie Aerospace Holdings Inc. (“McKechnie Aerospace”), a supplier of aerospace components, assemblies and subsystems, for approximately $1.27 billion. On March 9, 2011, the Company completed the divestiture of the fastener business acquired as part of McKechnie Aerospace for approximately $239.6 million, subject to adjustment. On April 7, 2011, the Company completed the divestiture of Aero Quality Sales, a distributor and service center of aircraft batteries and battery support equipment, for approximately $31.8 million. Neither the non-proprietary fastener business nor the Aero Quality Sales distribution business fit with TransDigm’s overall business direction.

We believe we are a leading global designer, producer and supplier of highly engineered aircraft components for use on nearly all commercial and military aircraft in service today. Our business is well diversified due to the broad range of products we offer to our customers. We estimate that overabout 90% of our net sales for fiscal year 20112012 were generated by proprietary products. In addition, for fiscal year 2011,2012, we estimate that we generated approximately 75%about ³/₄ of our net sales from products for which we are the sole source provider.

Most of our products generate significant aftermarket revenue. Once our parts are designed into and sold on a new aircraft, we generate net sales from aftermarket consumption over the life of that aircraft, which is generally estimated to be approximately 30 years. A typical platform can be produced for 20 to 30 years, giving us an estimated product life cycle of 50-60 years. We estimate that approximately 56%55% of our net sales in fiscal year 20112012 were generated from aftermarket sales, the vast majority of which come from the commercial and military aftermarkets. These aftermarket revenues have historically produced a higher gross margin and been more stable than sales to original equipment manufacturers, or OEMs.

Products

We primarily design, produce and supply highly-engineered proprietary aerospace components (and certain systems/subsystems) with significant aftermarket content. We seek to develop highly customized products to solve specific needs for aircraft operators and manufacturers. We attempt to differentiate ourselves based on engineering, service and manufacturing capabilities. We typically choose not to compete for non-proprietary “build to print” business because it frequently offers lower margins than proprietary products. We believe that our products have strong brand names within the industry and that we have a reputation for high quality, reliability and customer support.

Our business is well diversified due to the broad range of products that we offer to our customers. Some of our more significant product offerings, substantially all of which are ultimately provided to end-users in the aerospace industry, include mechanical/electro-mechanical actuators and controls, ignition systems and engine technology, specialized pumps and valves, power conditioning devices, specialized AC/DC electric motors and generators, NiCad batteries and chargers, engineered latching and locking devices, rods and locking devices, engineered connectors and elastomers, cockpit security components and systems, specialized cockpit displays, aircraft audio systems, specialized lavatory components, seatbelts and safety restraints, engineered interior surfaces and lighting and control technology.

Sales and Marketing

Consistent with our overall strategy, our sales and marketing organization is structured to continually develop technical solutions that meet customer needs. In particular, we attempt to focus on products and programs that will lead to high-margin, repeatable sales in the aftermarket.

We have structured our sales efforts along our major product offerings, assigning a product manager to certain products. Each product manager is expected to grow the sales and profitability of the products for which he or she is responsible and to achieve the targeted annual level of bookings, sales, new business and profitability for such products. The product managers are assisted by account managers and sales engineers who are responsible for covering major OEM and aftermarket accounts. Account managers and sales engineers are expected to be familiar with the personnel, organization and needs of specific customers, to achieve total bookings and new business goals at each account and, together with the product managers, to determine when additional resources are required at customer locations. Most of our sales personnel are evaluated, in part, on their bookings and their ability to identify and obtain new business opportunities.

Though typically performed by employees, the account manager function may be performed by independent representatives depending on the specific customer, product and geographic location. We also use a number of distributors to provide logistical support as well as primary customer contact with certain smaller accounts. Our major distributors are Aviall, Inc. (a subsidiary of The Boeing Company) and Satair A/S (a Danish public company on whose Boardsubsidiary of Directors Mr. Howley, our Chairman and Chief Executive Officer, served through October 2011)Airbus).

Manufacturing and Engineering

We maintain 2535 principal manufacturing facilities. OurMost of our manufacturing facilities typically compriseare comprised of manufacturing, distribution and engineering functions, and most facilities have certain administrative functions,

including management, sales and finance. We continually strive to improve productivity and reduce costs, including rationalization of operations, developing improved control systems that allow for accurate product profit and loss accounting, investing in equipment, tooling, information systems and implementing broad-based employee training programs. Management believes that our manufacturing systems and equipment contribute to our ability to compete by permitting us to meet the rigorous tolerances and cost sensitive price structure of aircraft component customers.

We attempt to differentiate ourselves from our competitors by producing uniquely engineered products with high quality and timely delivery. Our engineering costs are recorded in Cost of Sales and in Selling and Administrative captions in our Consolidated Statements of Income. Total engineering expense represents approximately 7%6% of our operating units’ aggregate costs, or approximately 4%3% of our consolidated net sales. Our proprietary products, and particularly our new product initiatives, are designed by our engineers and are intended to serve the needs of the aircraft component industry. These proprietary designs must withstand the extraordinary conditions and stresses that will be endured by products during use and meet the rigorous demands of our customers’ tolerance and quality requirements.

We use sophisticated equipment and procedures to comply with quality requirements, specifications and Federal Aviation Administration (the “FAA”) and OEM requirements. We perform a variety of testing procedures, including testing under different temperature, humidity and altitude levels, shock and vibration testing and X-ray fluorescent measurement. These procedures, together with other customer approved techniques for document, process and quality control, are used throughout our manufacturing facilities.

Customers

Our customers include: (1) distributors of aerospace components; (2) worldwide commercial airlines, including national and regional airlines; (3) large commercial transport and regional and business aircraft OEMs; (4) various armed forces of the United States and friendly foreign governments; (5) defense OEMs; (6) system suppliers; and (7) various other industrial customers. For the year ended September 30, 2011,2012, Boeing (which includes Aviall, Inc., a distributor of commercial aftermarket parts to airlines throughout the world) accounted for approximately 14%13% of our net sales. Our top ten customers for fiscal year 20112012 accounted for approximately 43% of our net sales. Products supplied to many of our customers are used on multiple platforms.

Active commercial production programs include the Boeing 737, 747, 767, 777 and 787, the Airbus A319/20/21, A330/A340 and A380, the Bombardier CRJ’s, Challenger and Challenger,Learjets, the Embraer RJ’s, the Cessna Citation family, the Raytheon Premier and Hawker and most Gulfstream airframes. Military platforms include aircraft such as the Boeing C-17, F-15, F-18 and V-22, the Lockheed Martin C-130J, F-16 and F-35 Joint Strikefighter, the Northrop Grumman E-2C Hawkeye, the UH-60 Blackhawk, CH-47 Chinook and AH-64 Apache helicopters, the General Atomics Predator Drone and the Raytheon Patriot Missile. TransDigm has been awarded numerous contracts for the development of engineered products for production on the Airbus A350XWB, A320 NEO and A400M programs, and the Bombardier Learjet 85.85, the Sikorsky S-97 and Boeing P-8 Poseidon.

We believe that we have strong customer relationships with almost all large commercial transport, regional, general aviation and military OEMs. The demand for our aftermarket parts and services depends on, among other things, the breadth of our installed OEM base, revenue passenger miles (“RPMs”), the size and age of the worldwide aircraft fleet and, to a lesser extent, airline profitability. We believe that we are also a leading supplier of components used on U.S.—designed military aircraft, including components that are used on a variety of fighter aircraft, military freighters and military helicopters.

Competition

The niche markets within the aerospace industry that we serve are relatively fragmented and we face several competitors for many of the products and services we provide. Due to the global nature of the commercial aircraft industry, competition in these categories comes from both U.S. and foreign companies. Competitors in our product offerings range in size from divisions of large public corporations to small privately-held entities, with only one or two components in their entire product portfolios.

We compete on the basis of engineering, manufacturing and marketing high quality products, which we believe meet or exceed the performance and maintenance requirements of our customers, consistent and timely delivery, and superior customer service and support. The industry’s stringent regulatory, certification and

technical requirements, and the investments necessary in the development and certification of products, create barriers to entry for potential new competitors. As long as customers receive products that meet or exceed expectations and performance standards, we believe that they will have a reduced incentive to certify another supplier because of the cost and time of the technical design and testing certification process. In addition, we believe that concerns aboutthe availability, dependability and safety and flight delays ifof our products are unavailable or undependable are reasons for our customers to continue long-term supplier relationships.

Government Contracts

Companies engaged in supplying defense-related equipment and services to U.S. Government agencies are subject to business risks specific to the defense industry. These risks include the ability of the U.S. Government to unilaterally: (1) suspend us from receiving new contracts pending resolution of alleged violations of procurement laws or regulations; (2) terminate existing contracts; (3) reduce the value of existing contracts; (4) audit our contract-related costs and fees, including allocated indirect costs; and (5) control and potentially prohibit the export of our products.

Governmental Regulation

The commercial aircraft component industry is highly regulated by both the FAA in the United States and by the Joint Aviation Authorities in Europe and other agencies throughout the world, while the military aircraft component industry is governed by military quality specifications. We, and the components we manufacture, are required to be certified by one or more of these entities or agencies, and, in many cases, by individual OEMs, in order to engineer and service parts and components used in specific aircraft models.

We must also satisfy the requirements of our customers, including OEMs and airlines that are subject to FAA regulations, and provide these customers with products and services that comply with the government regulations applicable to commercial flight operations. In addition, the FAA requires that various maintenance routines be performed on aircraft components. We believe that we currently satisfy or exceed these maintenance standards in our repair and overhaul services. We also maintain several FAA approved repair stations.

In addition, sales of many of our products that will be used on aircraft owned by non-U.S. entities are subject to compliance with U.S. export control laws.

Our operations are also subject to a variety of worker and community safety laws. The Occupational Safety and Health Act (“OSHA”), mandates general requirements for safe workplaces for all employees. In addition, OSHA provides special procedures and measures for the handling of certain hazardous and toxic substances.

Raw Materials

We require the use of various raw materials in our manufacturing processes. We also purchase a variety of manufactured component parts from various suppliers. At times, we concentrate our orders among a few suppliers in order to strengthen our supplier relationships. Raw materials and component parts are generally available from multiple suppliers at competitive prices.

Intellectual Property

We have various trade secrets, proprietary information, trademarks, trade names, patents, copyrights and other intellectual property rights, which we believe, in the aggregate but not individually, are important to our business.

Backlog

As of September 30, 2011,2012, the Company estimated its sales order backlog at $737$833 million compared to an estimated sales order backlog of $467$737 million as of September 30, 2010.2011. The increase in backlog is primarily due to the acquisitions of McKechnie Aerospace, Talley ActuationAero-Instruments, Harco and Schneller HoldingsAmSafe discussed below, totaling approximately $207$62 million as of September 30, 2011.and an increase in orders across existing OEM product lines and to a lesser extent the aftermarket. The majority of the purchase orders outstanding as of September 30, 20112012 are scheduled for delivery within the next twelve months. Purchase orders may be subject to cancellation or deferral by the customer prior to shipment. The level of unfilled purchase orders at any given date during the year will be materially affected by the timing of the Company’s receipt of purchase orders and the speed with which those orders are filled. Accordingly, the Company’s backlog as of September 30, 20112012 may not necessarily represent the actual amount of shipments or sales for any future period.

Foreign Operations

Although we manufacture substantially alla significant portion of our products in the United States, we manufacture some products in Belgium, China, Malaysia, Mexico, Sri Lanka and Mexico.the United Kingdom. We sell our products in the United States, as well as in foreign countries. Although the majority of sales of our products are made to customers including distributors located in the United States, our products are ultimately sold to and used by customers, including airlines and other end users of aircraft, throughout the world. A number of risks inherent in international operations could have a material adverse effect on our results of operations, including currency fluctuations, difficulties in staffing and managing multi-national operations, general economic and political uncertainties and potential for social unrest in countries in which we operate, limitations on our ability to enforce legal rights and remedies, restrictions on the repatriation of funds, change in trade policies, tariff regulation, difficulties in obtaining export and import licenses and the risk of government financed competition.

Our direct sales to foreign customers were approximately $508.8 million, $305.5 million, $170.6 million, and $150.4$170.6 million for fiscal years 2012, 2011 2010 and 2009,2010, respectively. Sales to foreign customers are subject to numerous additional risks, including the impact of foreign government regulations, political uncertainties and differences in business practices. There can be no assurance that foreign governments will not adopt regulations or take other action that would have a direct or indirect adverse impact on the business or market opportunities of the Company within such governments’ countries. Furthermore, there can be no assurance that the political, cultural and economic climate outside the United States will be favorable to our operations and growth strategy.

Environmental Matters

Our operations and facilities are subject to a number of federal, state, local and foreign environmental laws and regulations that govern, among other things, discharges of pollutants into the air and water, the generation, handling, storage and disposal of hazardous materials and wastes, the remediation of contamination and the health and safety of our employees. Environmental laws and regulations may require that the Company investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. At certainCertain facilities acquired in connection with the acquisition of McKechnie Aerospace orand third-party sites utilized by subsidiaries of McKechnie Aerospace, subsidiaries of the Company have been identified as potentially responsible parties under the federal Superfund laws and comparable state laws. The Company is currently involved in the investigation and remediation of a number of sites under applicable laws.

Estimates of the Company’s environmental liabilities are based on current facts, laws, regulations and technology. These estimates take into consideration the Company’s prior experience and professional judgment of the Company’s environmental specialists. Estimates of the Company’s environmental liabilities are further subject to uncertainties regarding the nature and extent of site contamination, the range of remediation alternatives available, evolving remediation standards, imprecise engineering evaluations and cost estimates, the extent of corrective actions that may be required and the number and financial condition of other potentially responsible parties, as well as the extent of their responsibility for the remediation.

Accordingly, as investigation and remediation proceed, it is likely that adjustments in the Company’s accruals will be necessary to reflect new information. The amounts of any such adjustments could have a

material adverse effect on the Company’s results of operations or cash flows in a given period. Based on currently available information, however, the Company does not believe that future environmental costs in excess of those accrued with respect to sites for which the Company has been identified as a potentially responsible party are likely to have a material adverse effect on the Company’s financial condition.

Environmental liabilities are recorded when the liability is probable and the costs are reasonably estimable, which generally is not later than at completion of a feasibility study or when the Company has recommended a remedy or has committed to an appropriate plan of action. The liabilities are reviewed periodically and, as investigation and remediation proceed, adjustments are made as necessary. Liabilities for losses from environmental remediation obligations do not consider the effects of inflation and anticipated expenditures are not discounted to their present value. The liabilities are not reduced by possible recoveries from insurance carriers or other third parties, but do reflect anticipated allocations among potentially responsible parties at federal Superfund sites or similar state-managed sites, third party indemnity obligations, and an assessment of the likelihood that such parties will fulfill their obligations at such sites.

Employees

As of September 30, 2011,2012, we had approximately 3,8005,400 full time, part time and temporary employees. Approximately 16%12% of our employees were represented by labor unions. Collective bargaining agreements between us and these labor unions expire at various dates ranging from FebruaryNovember 2012 to April 2014.2016. We consider our relationship with our employees generally to be satisfactory.

Legal Proceedings

We are from time to time subject to, and are presently involved in, litigation or other legal proceedings arising in the ordinary course of business. Based upon information currently known to us, we believe the outcome of such proceedings will not have, individually or in the aggregate, a material adverse effect on our business, our financial condition or results of operations.

Available Information

TD Group’s Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, including any amendments, will be made available free of charge on the Company’s website,www.transdigm.com, as soon as reasonably practicable, following the filing of the reports with the Securities and Exchange Commission.

Set forth below are important risks and uncertainties that could negatively affect our business and financial condition and could cause our actual results to differ materially from those expressed in forward-looking statements contained in this report.

Our business is sensitive to the number of flight hours that our customers’ planes spend aloft, the size and age of the worldwide aircraft fleet and our customers’ profitability. These items are, in turn, affected by general economic conditions.

Our business is directly affected by, among other factors, changes in revenue passenger miles (RPMs), the size and age of the worldwide aircraft fleet and, to a lesser extent, changes in the profitability of the commercial airline industry. RPMs and airline profitability have historically been correlated with the general economic environment, although national and international events also play a key role. For example, in the recent past, decade, the airline industry has been severely affected by the downturn in the global economy, higher fuel prices, the increased security concerns among airline customers following the events of September 11, 2001, the Severe

Acute Respiratory Syndrome, or SARS, epidemic and the conflicts in Afghanistan and Iraq. In addition, global market and economic conditions have been challenging with continued turbulence in the U.S. and international markets and economies and have prolonged declines in business and consumer spending. As a result of the substantial reduction in airline traffic resulting from these events, the airline industry incurred large losses and financial difficulties. Some carriers have also parked or retired a portion of their fleets and have reduced workforces and flights. During periods of reduced airline profitability, some airlines may delay purchases of spare parts, preferring instead to deplete existing inventories. If demand for new aircraft and spare parts decreases, there would be a decrease in demand for certain of our products.

Our sales to manufacturers of aircraft are cyclical, and a downturn in sales to these manufacturers may adversely affect us.

Our sales to manufacturers of large commercial aircraft, such as The Boeing Company, Airbus S.A.S, and related OEM suppliers, as well as manufacturers of business jets, which accounted for approximately 25%26% of our net sales in fiscal year 2011,2012, have historically experienced periodic downturns. In the past, these sales have been affected by airline profitability, which is impacted by, among other things, fuel and labor costs, price competition, downturns in the global economy and national and international events, such as the events of September 11, 2001. In addition, sales of our products to manufacturers of business jets are impacted by, among other things, downturns in the global economy. Prior downturns have adversely affected our net sales, gross margin and net income.

We rely heavily on certain customers for much of our sales.

Our largest customer for fiscal year 20112012 was The Boeing Company (which includes Aviall, Inc., a distributor of commercial aftermarket parts to airlines throughout the world). Boeing accounted for approximately 14%13% of our net sales in fiscal year 2011.2012. Our top ten customers for fiscal year 20112012 accounted for approximately 43% of our net sales. A reduction in purchasing by one of our larger customers for any reason, such as economic downturn, decreased production or strike, could have a material adverse effect on our net sales, gross margin and net income.

We generally do not have guaranteed future sales of our products. Further, when we enter into fixed price contracts with some of our customers, we take the risk for cost overruns.

As is customary in our business, we do not generally have long-term contracts with most of our aftermarket customers and, therefore, do not have guaranteed future sales. Although we have long-term contracts with many of our OEM customers, many of those customers may terminate the contracts on short notice and, in most cases, our customers have not committed to buy any minimum quantity of our products. In addition, in certain cases, we must anticipate the future volume of orders based upon the historic purchasing patterns of customers and upon our discussions with customers as to their anticipated future requirements, and this anticipated future volume of orders may not materialize.

We also have entered into multi-year, fixed-price contracts with some of our customers, pursuant to which we have agreed to perform the work for a fixed price and, accordingly, realize all the benefit or detriment resulting from any decreases or increases in the costs of making these products. Sometimes we accept a fixed-price contract for a product that we have not yet produced, and this increases the risk of cost overruns or delays in the completion of the design and manufacturing of the product. Most of our contracts do not permit us to recover increases in raw material prices, taxes or labor costs.

U.S. military spending is dependent upon the U.S. defense budget.

The military and defense market is significantly dependent upon government budget trends, particularly the U.S. Department of Defense (the “DOD”) budget. In addition to normal business risks, our supply of products to

the United States Government is subject to unique risks largely beyond our control. Future DOD budgets could

be negatively impacted by several factors, including, but not limited to, a change in defense spending policy by the current presidential administration, the U.S. Government’s budget deficits, spending priorities, the cost of sustaining the U.S. military presence in Iraq and Afghanistanthe Middle East and possible political pressure to reduce U.S. Government military spending, each of which could cause the DOD budget to remain unchanged or to decline. A significant decline in U.S. military expenditures in the future could result in a reduction in the amount of our products sold to the various agencies and buying organizations of the U.S. Government.

We intend to pursue future acquisitions. Our business may be adversely affected if we cannot consummate acquisitions on satisfactory terms, or if we cannot effectively integrate acquired operations.

A significant portion of our growth has occurred through acquisitions. Any future growth through acquisitions will be partially dependent upon the continued availability of suitable acquisition candidates at favorable prices and upon advantageous terms and conditions. We intend to pursue acquisitions that we believe will present opportunities consistent with our overall business strategy. However, we may not be able to find suitable acquisition candidates to purchase or may be unable to acquire desired businesses or assets on economically acceptable terms. In addition, we may not be able to raise the capital necessary to fund future acquisitions. Because we may actively pursue a number of opportunities simultaneously, we may encounter unforeseen expenses, complications and delays, including difficulties in employing sufficient staff and maintaining operational and management oversight.

We regularly engage in discussions with respect to potential acquisition and investment opportunities. If we consummate an acquisition, our capitalization and results of operations may change significantly. Future acquisitions could likely result in the incurrence of additional debt and contingent liabilities and an increase in interest and amortization expenses or periodic impairment charges related to goodwill and other intangible assets as well as significant charges relating to integration costs.

Acquisitions involve risks that the businesses acquired will not perform in accordance with expectations and that business judgments concerning the value, strengths and weaknesses of businesses acquired will prove incorrect. In addition, we may not be able to successfully integrate any business we acquire into our existing business. The successful integration of new businesses depends on our ability to manage these new businesses and cut excess costs. The successful integration of future acquisitions may also require substantial attention from our senior management and the management of the acquired business, which could decrease the time that they have to service, attract customers and develop new products and services or attend to other acquisition opportunities.

We are subject to certain unique business risks as a result of supplying equipment and services to the U.S. Government.

Companies engaged in supplying defense-related equipment and services to U.S. Government agencies are subject to business risks specific to the defense industry. These risks include the ability of the U.S. Government to unilaterally:

Most of our U.S. Government contracts can be terminated by the U.S. Government for its convenience without significant notice. Termination for convenience provisions provide only for our recovery of costs incurred or committed, settlement expenses and profit on the work completed prior to termination.

On contracts for which the price is based on cost, the U.S. Government may review our costs and performance, as well as our accounting and general business practices. Based on the results of such audits, the U.S. Government may adjust our contract-related costs and fees, including allocated indirect costs. In addition, under U.S. Government purchasing regulations, some of our costs, including most financing costs, amortization of intangible assets, portions of research and development costs, and certain marketing expenses may not be subject to reimbursement.

In addition, even where the price is not based on cost, the U.S. Government may seek to review our costs to determine whether our pricing is “fair and reasonable”. Five of our subsidiaries and divisions were subject to such a pricing review for years 2002 through 2004 and it is possible that we will be subject to a similar pricing review in the future. Such a review could be costly and time consuming for our management and could distract from our ability to effectively manage the business. As a result of such a review, we could be subject to providing a refund to the U.S. Government or we could be asked to enter into an arrangement whereby our prices would be based on cost or the DOD could seek to pursue alternative sources of supply for our parts. Any of those occurrences could lead to a reduction in our revenue from, or the profitability of certain of our supply arrangements with, certain agencies and buying organizations of the U.S. Government.

Our business may be adversely affected if we would lose our government or industry approvals or if more stringent government regulations are enacted or if industry oversight is increased.

The aerospace industry is highly regulated in the United States and in other countries. In order to sell our components, we and the components we manufacture must be certified by the FAA, the DOD and similar agencies in foreign countries and by individual manufacturers. If new and more stringent government regulations are adopted or if industry oversight increases, we might incur significant expenses to comply with any new regulations or heightened industry oversight. In addition, if material authorizations or approvals were revoked or suspended, our business would be adversely affected.

In addition to the aviation approvals, we are at times required to obtain approval from U.S. Government agencies to export our products. Additionally, we are not permitted to export some of our products. A determination by the U.S. Government that we failed to receive required approvals or licenses could eliminate or restrict our ability to sell our products outside the United States, and the penalties that could be imposed by the U.S. Government for failure to comply with these laws could be significant.

Our substantial indebtedness could adversely affect our financial health and could harm our ability to react to changes to our business and prevent us from fulfilling our obligations under our indebtedness.

We have a significant amount of indebtedness. As of September 30, 2011,2012, our total indebtedness was approximately $3,138.4$3,619.1 million, which was approximately 79.5%74.8% of our total capitalization.

In addition, we may be able to incur substantial additional indebtedness in the future. For example, as of September 30, 2011,2012, we had approximately $237.0$302.9 million of unused commitments under our revolving loan facility. Although our senior secured credit facility and the indentures (the(together with the indenture governing the 5 ¹/₂% notes discussed below, the “Indentures”) governing the 7 ³/₄% senior subordinated notes issued in December 2010 (the “7 ³/₄% Senior Subordinated Notes”) contain restrictions on the incurrence of additional indebtedness, these restrictions are subject to a number of significant qualifications and exceptions, and the indebtedness incurred in compliance with these qualifications and exceptions could be substantial. If we incur additional debt, the risks associated with our substantial leverage would increase.

Our substantial indebtedness could have important consequences to investors. For example, it could:

In addition, all of our debt under the senior secured credit facility, which includes a $1.55$2.02 billion term loan facility and a revolving loan facility of $245$310.0 million, bears interest at floating rates. Accordingly, in the event that interest rates increase, our debt service expense will also increase. In order to reduce the floating interest rate risk, as of September 30, 2011,2012, the Company was party to three forward starting interest rate swap agreements that fix the rate of interest beginning December 31, 2012 through June 30, 2015 on an aggregate notional amount of $353 million of debt under the senior secured credit facility.

On October 9, 2012, the Company amended the secured credit facility to provide for an additional term loan facility in the aggregate principal amount of $150 million. The additional term loan facility was fully drawn on October 15, 2012. The Company also issued $550 million in aggregate principal amount of its 5 ¹/₂% Senior Subordinated Notes due 2020 (the “5 ¹/₂% Senior Subordinated Notes”) at an issue price of 100% of the principal amount on October 15, 2012.

Our substantial level of indebtedness increases the possibility that we may be unable to generate cash sufficient to pay, when due, the principal of, interest on or other amounts due in respect of our indebtedness, including the 7 ³/₄% Senior Subordinated Notes.Notes (as well as the 5 ¹/₂% Senior Subordinated Notes). We cannot assure you that our business will generate sufficient cash flow from operations or that future borrowings will be available to us under the senior secured credit facility or otherwise in amounts sufficient to enable us to service our indebtedness. If we cannot service our debt, we will have to take actions such as reducing or delaying capital investments, selling assets, restructuring or refinancing our debt or seeking additional equity capital.

To service our indebtedness, we will require a significant amount of cash. Our ability to generate cash depends on many factors beyond our control and any failure to meet our debt service obligations could harm our business, financial condition and results of operations.

Our ability to make payments on our indebtedness, including the 7 ³/₄% Senior Subordinated Notes (as well as the 5 ¹/₂% Senior Subordinated Notes) and amounts borrowed under the credit facilities, and to fund our operations, will depend on our ability to generate cash in the future, which, to a certain extent, is subject to general economic, financial, competitive, legislative, regulatory and other factors that are beyond our control.

We cannot assure you, however, that our business will generate sufficient cash flow from operations, that currently anticipated cost savings and operating improvements will be realized on schedule or at all or that future borrowings will be available to us under the senior secured credit facility or otherwise in amounts sufficient to enable us to service our indebtedness, including the amounts borrowed under the senior secured credit facility and the 7 ³/₄% Senior Subordinated Notes (as well as the 5 ¹/₂% Senior Subordinated Notes), or to fund our other liquidity needs. If we cannot service our debt, we will have to take actions such as reducing or delaying capital investments, selling assets, restructuring or refinancing our debt or seeking additional equity capital. We cannot assure you that any of these remedies could, if necessary, be effected on commercially reasonable terms, or at all. Our ability to restructure or refinance our debt will depend on the condition of the capital markets and our financial condition at such time. Any refinancing of our debt could be at higher interest rates and may require us

to comply with more onerous covenants, which could further restrict our business operations. The terms of existing or future debt instruments, the Indentures and the senior secured credit facility may restrict us from adopting any of these alternatives. In addition, any failure to make payments of interest and principal on our outstanding indebtedness on a timely basis would likely result in a reduction of our credit rating, which could harm our ability to incur additional indebtedness on acceptable terms and would otherwise adversely affect the 7 ³/₄% Senior Subordinated Notes.Notes (as well as the 5 ¹/₂% Senior Subordinated Notes).

The terms of the senior secured credit facility and Indentures may restrict our current and future operations, particularly our ability to respond to changes or to take certain actions.

Our senior secured credit facility and the Indentures contain a number of restrictive covenants that impose significant operating and financial restrictions on TD Group, TransDigm Inc. and its subsidiaries (in the case of

the senior secured credit facility) and TransDigm Inc. and its subsidiaries (in the case of the Indentures) and may limit their ability to engage in acts that may be in our long-term best interests. The senior secured credit facility and Indentures include covenants restricting, among other things, the ability of TD Group, TransDigm Inc. and its subsidiaries (in the case of the senior secured credit facility) and TransDigm Inc. and its subsidiaries (in the case of the Indentures) to:

A breach of any of these covenants could result in a default under the senior secured credit facility or the Indentures. If any such default occurs, the lenders under the senior secured credit facility and the holders of the 7 ³/₄% Senior Subordinated Notes (as well as the 5 ¹/₂% Senior Subordinated Notes) may elect to declare all outstanding borrowings, together with accrued interest and other amounts payable thereunder, to be immediately due and payable. The lenders under the senior secured credit facility also have the right in these circumstances to terminate any commitments they have to provide further borrowings. In addition, following an event of default under the senior secured credit facility, the lenders under that facility will have the right to proceed against the collateral granted to them to secure the debt, which includes our available cash, and they will also have the right to prevent us from making debt service payments on the 7 ³/₄% Senior Subordinated Notes.Notes (as well as the 5 ¹/₂% Senior Subordinated Notes). If the debt under the senior secured credit facility or the 7 ³/₄% Senior Subordinated Notes (as well as the 5 ¹/₂% Senior Subordinated Notes) were to be accelerated, we cannot assure you that our assets would be sufficient to repay in full our debt.

We could incur substantial costs as a result of violations of or liabilities under environmental laws and regulations.

Our operations and facilities are subject to a number of federal, state, local and foreign environmental laws and regulations that govern, among other things, discharges of pollutants into the air and water, the generation, handling, storage and disposal of hazardous materials and wastes, the remediation of contamination and the

health and safety of our employees. Environmental laws and regulations may require that the Company investigate and remediate the effects of the release or disposal of materials at sites associated with past and present operations. At certainCertain facilities acquired in connection with the acquisition of McKechnie Aerospace orand third-party sites utilized by subsidiaries of McKechnie Aerospace, subsidiaries of the Company have been identified as potentially responsible parties under the federal Superfund laws and comparable state laws. The Company is currently involved in the investigation and remediation of a number of sites under applicable laws.

Estimates of the Company’s environmental liabilities are based on current facts, laws, regulations and technology. These estimates take into consideration the Company’s prior experience and professional judgment of the Company’s environmental specialists. Estimates of the Company’s environmental liabilities are further subject to uncertainties regarding the nature and extent of site contamination, the range of remediation alternatives available, evolving remediation standards, imprecise engineering evaluations and cost estimates, the extent of corrective actions that may be required and the number and financial condition of other potentially responsible parties, as well as the extent of their responsibility for the remediation.

Accordingly, as investigation and remediation proceed, it is likely that adjustments in the Company’s accruals will be necessary to reflect new information. The amounts of any such adjustments could have a material adverse effect on the Company’s results of operations or cash flows in a given period. Based on currently available information, however, the Company does not believe that future environmental costs in excess of those accrued with respect to sites for which the Company has been identified as a potentially responsible party are likely to have a material adverse effect on the Company’s financial condition.

Environmental liabilities are recorded when the liability is probable and the costs are reasonably estimable, which generally is not later than at completion of a feasibility study or when the Company has recommended a remedy or has committed to an appropriate plan of action. The liabilities are reviewed periodically and, as investigation and remediation proceed, adjustments are made as necessary. Liabilities for losses from environmental remediation obligations do not consider the effects of inflation and anticipated expenditures are not discounted to their present value. The liabilities are not reduced by possible recoveries from insurance carriers or other third parties, but do reflect anticipated allocations among potentially responsible parties at federal Superfund sites or similar state-managed sites, third party indemnity obligations, and an assessment of the likelihood that such parties will fulfill their obligations at such sites.

We are dependent on our highly trained employees and any work stoppage or difficulty hiring similar employees could adversely affect our business.

Because our products are complicated and highly engineered, we depend on an educated and trained workforce. There is substantial competition for skilled personnel in the aircraft component industry, and we could be adversely affected by a shortage of skilled employees. We may not be able to fill new positions or vacancies created by expansion or turnover or attract and retain qualified personnel.

As of September 30, 2011,2012, we had approximately 3,8005,400 full time, part time and temporary employees. Approximately 16%12% of our employees were represented by labor unions. Collective bargaining agreements between us and these labor unions expire at various dates ranging from FebruaryNovember 2012 to April 2014.2016. We consider our relationship with our employees generally to be satisfactory. Although we believe that our relations with our employees are satisfactory, we cannot assure you that we will be able to negotiate a satisfactory renewal of these collective bargaining agreements or that our employee relations will remain stable. Because we maintain a relatively small inventory of finished goods, any work stoppage could materially and adversely affect our ability to provide products to our customers.

Our business is dependent on the availability of certain components and raw materials from suppliers.

Our business is affected by the price and availability of the raw materials and component parts that we use to manufacture our components. Our business, therefore, could be adversely impacted by factors affecting our

suppliers (such as the destruction of our suppliers’ facilities or their distribution infrastructure, a work stoppage or strike by our suppliers’ employees or the failure of our suppliers to provide materials of the requisite quality), or by increased costs of such raw materials or components if we were unable to pass along such price increases to our customers. Because we maintain a relatively small inventory of raw materials and component parts, our business could be adversely affected if we were unable to obtain these raw materials and components from our suppliers in the quantities we require or on favorable terms. Although we believe in most cases that we could identify alternative suppliers, or alternative raw materials or component parts, the lengthy and expensive FAA and OEM certification processes associated with aerospace products could prevent efficient replacement of a supplier, raw material or component part.

Our facilities are located near known earthquake fault zones, and the occurrence of an earthquake or other natural disaster could cause damage to our facilities and equipment, which could require us to curtail or cease operations.

SixA number of our manufacturing facilities are located in the greater Los Angeles area, an area known for earthquakes, and are thus vulnerable to damage. We are also vulnerable to damage from other types of disasters,

including power loss, fire, explosions, floods, communications failures, terrorist attacks and similar events. If any disaster were to occur, our ability to operate our business at our facilities could be impaired.

We have recorded a significant amount of intangible assets, which may never generate the returns we expect.

Mergers and acquisitions have resulted in significant increases in identifiable intangible assets and goodwill. Identifiable intangible assets, which primarily include trademarks, trade names, trade secrets, license agreements and technology, were approximately $828.4$1,123.6 million at September 30, 2011,2012, representing approximately 18%21% of our total assets. Goodwill recognized in accounting for the mergers and acquisitions was approximately $2,595.7$3,035.5 million at September 30, 2011,2012, representing approximately 58%56% of our total assets. We may never realize the full value of our identifiable intangible assets and goodwill, and to the extent we were to determine that our identifiable intangible assets or our goodwill were impaired within the meaning of applicable accounting standards, we would be required to write-off the amount of any impairment.

We face significant competition.

We operate in a highly competitive global industry and compete against a number of companies. Competitors in our product lines are both U.S. and foreign companies and range in size from divisions of large public corporations to small privately held entities. We believe that our ability to compete depends on high product performance, consistent high quality, short lead-time and timely delivery, competitive pricing, superior customer service and support and continued certification under customer quality requirements and assurance programs. We may have to adjust the prices of some of our products to stay competitive.

We could be adversely affected if one of our components causes an aircraft to crash.

Our operations expose us to potential liabilities for personal injury or death as a result of the failure of an aircraft component that we have designed, manufactured or serviced. While we maintain liability insurance to protect us from future products liability claims, in the event of product liability claims our insurers may attempt to deny coverage or any coverage we have may not be adequate. We also may not be able to maintain insurance coverage in the future at an acceptable cost. Any liability not covered by insurance or for which third party indemnification is not available could result in significant liability to us.

In addition, a crash caused by one of our components could damage our reputation for quality products. We believe our customers consider safety and reliability as key criteria in selecting a provider of aircraft components. If a crash were to be caused by one of our components, or if we were to otherwise fail to maintain a satisfactory record of safety and reliability, our ability to retain and attract customers may be materially adversely affected.

Our stock price may be volatile, and your investment in our common stock could suffer a decline in value.

There has been significant volatility in the market price and trading volume of equity securities, which is unrelated to the financial performance of the companies issuing the securities. These broad market fluctuations may negatively affect the market price of our common stock. You may not be able to sell your shares at or above the purchase price due to fluctuations in the market price of our common stock caused by changes in our operating performance or prospects, including possible changes due to the cyclical nature of the aerospace industry and other factors such as fluctuations in OEM and aftermarket ordering, which could cause short-term swings in profit margins, or unrelated to our operating performance, including market conditions affecting the stock market generally or the stocks of aerospace companies more specifically.

Future sales of our common stock in the public market could lower our share price.

We may sell additional shares of common stock into the public markets or issue convertible debt securities to raise capital in the future. The market price of our common stock could decline as a result of sales of a large number of shares of our common stock in the public markets or the perception that these sales could occur. These sales, or the possibility that these sales may occur, also might make it more difficult for us to sell equity securities to raise capital at a time and price that we deem appropriate.

Our corporate documents and Delaware law contain certain provisions that could discourage, delay or prevent a change in control of our company.

Provisions in our amended and restated certificate of incorporation and bylaws may discourage, delay or prevent a merger or acquisition involving us that our stockholders may consider favorable. For example, our amended and restated certificate of incorporation authorizes our Board of Directors to issue up to 149,600,000 shares of “blank check” preferred stock. Without stockholder approval, the Board of Directors has the authority to attach special rights, including voting and dividend rights, to this preferred stock. With these rights, holders of preferred stock could make it more difficult for a third party to acquire us. In addition, our amended and restated certificate of incorporation provides for a staggered Board of Directors, whereby directors serve for three-year terms, with approximately one-third of the directors coming up for re-election each year. Having a staggered board will make it more difficult for a third party to obtain control of our Board of Directors through a proxy contest, which may be a necessary step in an acquisition of us that is not favored by our Board of Directors. Our amended and restated certificate of incorporation also provides that the affirmative vote of the holders of at least 75% of the voting power of our issued and outstanding capital stock, voting together as a single class, is required for the alteration, amendment or repeal of certain provisions of our amended and restated certificate of incorporation, including the provisions authorizing a staggered board, and certain provisions of our amended and restated bylaws, including the provisions relating to our stockholders’ ability to call special meetings, notice provisions for stockholder business to be conducted at an annual meeting, requests for stockholder lists and corporate records, nomination and removal of directors, and filling of vacancies on our Board of Directors.

We are also subject to the anti-takeover provisions of Section 203 of the Delaware General Corporation Law. Under these provisions, if anyone becomes an “interested stockholder,” we may not enter into a “business combination” with that person for three years without special approval, which could discourage a third party from making a takeover offer and could delay or prevent a change of control. For purposes of Section 203, “interested stockholder” means, generally, someone owning 15% or more of our outstanding voting stock or an affiliate of ours that owned 15% or more of our outstanding voting stock during the past three years, subject to certain exceptions as described in Section 203.

We do not intend to pay regular quarterly or annual cash dividends on our stock.

On October 15, 2012 the Company’s Board of Directors authorized and declared a special cash dividend of $12.85 on each outstanding share of common stock and cash dividend equivalent payments under certain of its

stock option plans. The special cash dividend amounting to approximately $663.5 million was paid in November 2012 and Dividend Equivalent Payments amounting to approximately $36.0 million will be paid prior to December 31, 2012. The Company declared and paid a special cash dividend of $7.65 on each outstanding share of common stock in October 2009.

Notwithstanding the special cash dividenddividends paid in October 2009 and November 2012, we do not anticipate declaring or paying regular quarterly or annual cash dividends on our common stock or any other equity security in the foreseeable future. The amounts that may be available to us to pay cash dividends are restricted under our debt and other agreements. Any payment of cash dividends on our common stock in the future will be at the discretion of our Board of Directors and will depend on our results of operations, earnings, capital requirements, financial condition, future prospects, contractual restrictions and other factors deemed relevant by our Board of Directors. Therefore, you should not rely on quarterly or annual dividend income from shares of our common stock.

None.

ITEM 2.

PROPERTIES

TransDigm’s owned properties as of September 30, 20112012 are as follows:

The properties listed above, except Valencia,Bridport, Phoenix, Kent, Pinellas Park, BelgiumHerstal, Branford, Valencia and MalaysiaMelaka are subject to mortgage liens under our senior secured credit facility. The Seattle property is currently held for sale.vacant and under contract to sell.

TransDigm’s leased properties as of September 30, 20112012 are as follows:

Location		Square Footage
Cleveland, OH			12,40015,200
Cleveland, OH			13,100
Wichita, KS			10,000
Bookham, United Kingdom			9,900
Placentia, CA			8,400
Irvine,Pasadena, CA			5,6005,300
Brownsville, TXBorella, Sri Lanka			2,5004,900
Paris, France			2,100
Wichita, KS			1,700
Singapore			1,700
Kunshan, China			1,300

TransDigm also leases certain of its other non-material facilities. Management believes that our machinery, plants and offices are in satisfactory operating condition and that it will have sufficient capacity to meet foreseeable future needs without incurring significant additional capital expenditures.

During the ordinary course of business, TransDigm is from time to time threatened with, or may become a party to, legal actions and other proceedings related to its businesses, products or operations. While TransDigm is currently involved in some legal proceedings, management believes the results of these proceedings will not have a material effect on its financial condition, results of operations, or cash flows.

PART II

Market Information

Our common stock is traded on the New York Stock Exchange, or NYSE, under the ticker symbol “TDG.” The following chart sets forth, for the periods indicated, the high and low sales prices of the common stock on the NYSE.

Holders

On October 31, 2012, there were 29 stockholders of record of our common stock. We estimate that there were approximately 4,90055,228 beneficial holders of our common stockstockholders as of October 31, 2011.2012, which includes an estimated amount of stockholders who have their shares held in their accounts by banks and brokers.

Dividends

In October 2009 TD Group’s Board of Directors declared a special cash dividend of $7.65 on each outstanding share of common stock. Also, in October 2012 TD Group’s Board of Directors declared a special cash dividend of $12.85 on each outstanding share of common stock.

We do not anticipate declaring or paying regular quarterly or annual cash dividends on our common stock in the near future. Any payment of cash dividends on our common stock in the future will be at the discretion of our Board of Directors and will depend upon our results of operations, earnings, capital requirements, financial condition, future prospects, contractual restrictions, and other factors deemed relevant by our Board of Directors. TD Group is a holding company and conducts all of its operations through direct and indirect subsidiaries. Unless TD Group receives dividends, distributions, advances, transfers of funds or other payments from our subsidiaries, TD Group will be unable to pay any dividends on our common stock in the future. The ability of any subsidiaries to take any of the foregoing actions is limited by the terms of our debt documents and may be limited by future debt or other agreements that we may enter into.

Performance Graph

Set forth below is a line graph comparing the cumulative total return of a hypothetical investment in the shares of common stock of TD Group with the cumulative total return of a hypothetical investment in each of the S&P Midcap 400 Index and the S&P MidCap 400 S&P Aerospace & Defense Index, S&P SmallCap 600 Index and the S&P SmallCap 600 Aerospace & Defense Index based on the respective market prices of each such investment on the dates shown below, assuming an initial investment of $100 on September 30, 2006. The Company has concluded that the S&P Midcap 400 Index and the S&P MidCap 400 S&P Aerospace & Defense Index allow for more appropriate comparisons, as compared to the S&P SmallCap 600 Index and S&P SmallCap 600 Aerospace & Defense Index previously used, due to the growth in the market capitalization of TD Group.2007.

The following performance graph and related information shall not be deemed “soliciting material” nor to be “filed” with the SEC, nor shall such information be incorporated by reference into any future filings under the Securities Act of 1933 or the Securities Exchange Act of 1934, each as amended, except to the extent we specifically incorporate it by reference into such filing.

Purchases of Equity Securities by the Issuer or Affiliated Purchaser

On August 22, 2011 we announced a program permitting us to repurchase a portion of our outstanding shares not to exceed $100 million in the Board of Directors authorized a common share repurchase program, which was announced on August 23, 2011. Underaggregate. During the terms of the program,year ended September 30, 2012, the Company may purchase up to a maximum aggregate value of $100 millionrepurchased 11,300 shares of its sharescommon stock at a gross cost of common stock. At September 30, 2011, no shares were

repurchased under this program.approximately $0.8 million at a weighted-average price per share of $74.87 per share. The program replaces the repurchase program announced on October 23, 2008, under which the Company previously repurchased 494,100 shares of its common stock at a gross cost of approximately $15.2 million at a weighted-average price per share of $30.85. No purchases were made under that program during the year.

Equity Compensation Plan Information

2003 Stock Option Plan

In connection with the acquisition of the Company by Warburg Pincus in 2003, TD Group adopted a stock option plan for the benefit of our employees. The stock option plan has been amended and restated on several occasions, most recently effective as of July 18, 2008 and we refer to such stock option plan as it is currently in effect as the 2003 stock option plan.

Upon the closing of the acquisition of the Company by Warburg Pincus, certain employees rolled over certain then-existing options to purchase shares of common stock of TransDigm Inc.’s former holding company with an aggregate intrinsic value of approximately $35.7 million into a combination of options to purchase shares of common stock of TD Group, or rollover options, and interests in the two deferred compensation plans which have since been terminated. These employees were granted rollover options to purchase an aggregate of 3,870,152 shares of TD Group common stock, which gives effect to the 149.60 for 1.00 stock split that we effected on March 14, 2006 in connection with our initial public offering. All rollover options granted in connection with the closing of the acquisition were fully vested on the date of grant. As of September 30, 2011, there were2012, all rollover options to purchase 84,436 shares of TD Group common stock issued and outstanding (after giving effect to the stock split).were exercised.

In addition to the shares of TD Group common stock reserved for issuance upon exercise of rollover options, under the terms of the 2003 stock option plan, an aggregate of 5,469,301 shares of TD Group common stock are reserved for issuance upon exercise of new management options (after giving effect to the stock split). As of September 30, 2011,2012, there were new management options to purchase 2,096,2101,052,122 shares of TD Group common stock outstanding (after giving effect to the stock split). As of September 30, 2011,2012, there were 77,829 shares available for issuance under options not yet granted.

2006 Stock Incentive Plan

Prior to the consummation of its initial public offering, TD Group adopted a new stock incentive plan, which was amended on October 20, 2006, July 29, 2008 and March 3, 2011, designed to assist us in attracting,

retaining, motivating and rewarding key employees, directors or consultants, and promoting the creation of long-term value for stockholders of TD Group by closely aligning the interests of these individuals with those of our stockholders. The 2006 stock incentive plan permits TD Group to award our key employees, directors or consultants stock options, restricted stock and other stock-based incentives. The total number of shares of TD Group common stock reserved for issuance or delivery under the 2006 stock incentive plan is 8,119,668, subject to adjustment in the event of any stock dividend or split, reorganization, recapitalization, merger, share exchange

or any other similar corporate transaction or event. As of September 30, 2011,2012, there were 3,848 restricted22,944 shares of common stock issued and outstanding under the 2006 stock incentive plan that had been issued to directors as restricted stock.directors. In addition, options to purchase 4,697,4934,954,108 shares had been issued thereunder, of which 4,636,0854,726,195 were outstanding. As of September 30, 2011,2012, there were 3,400,1513,142,616 shares available for issuance under options not yet granted.

Other Option Awards

In connection with the acquisition of the Company by Warburg Pincus, the Company issued 132,096 options to Michael Graff, a director of the Company. Because Mr. Graff was not an employee of the Company and because participation in the 2003 Stock Option Plan was limited to employees, the options were issued outside of the 2003 Stock Option Plan. All of the options awarded to Mr. Graff are vested. As of September 30, 2011, 48,0962012, 16,096 options remained outstanding and exercisable.

ITEM 6.

SELECTED FINANCIAL DATA

The following table sets forth selected historical consolidated financial and other data of TD Group for the fiscal years ended September 30, 20072008 to 20112012 which have been derived from TD Group’s audited consolidated financial statements.

Separate historical financial information of TransDigm Inc. is not presented since the 7 ³/₄% Senior Subordinated Notes and the 5 ¹/₂% Senior Subordinated Notes are guaranteed by TD Group and all direct and indirect domestic restricted subsidiaries of TransDigm Inc. and since TD Group has no operations or significant assets separate from its investment in TransDigm Inc.

Acquisitions of businesses and product lines completed by TD Group during the last five fiscal years are as follows:

All of the acquisitions were accounted for using the acquisition method. The results of operations of the acquired businesses and product lines are included in TD Group’s consolidated financial statements from the date of each of the acquisitions.

Non-GAAP Financial Measures

We present below certain financial information based on our EBITDA and EBITDA As Defined. References to “EBITDA” mean earnings before interest, taxes, depreciation and amortization, and references to “EBITDA

“EBITDA As Defined” mean EBITDA plus, as applicable for each relevant period, certain adjustments as set forth in the reconciliations of net income to EBITDA and EBITDA As Defined and the reconciliations of net cash provided by operating activities to EBITDA and EBITDA As Defined presented below.

Neither EBITDA nor EBITDA As Defined is a measurement of financial performance under accounting principles generally accepted in the United States of America (“GAAP”). We present EBITDA and EBITDA As Defined because we believe they are useful indicators for evaluating operating performance and liquidity.

Our management believes that EBITDA and EBITDA As Defined are useful as indicators of liquidity because securities analysts, investors, rating agencies and others use EBITDA to evaluate a company’s ability to incur and service debt. In addition, EBITDA As Defined is useful to investors because the revolving credit facility under our senior secured credit facility requires compliance, on a pro forma basis, with a financial covenant that measures the ratio of the amount of our secured indebtedness to the amount of our Consolidated EBITDA defined in the same manner as we define EBITDA As Defined herein. This financial covenant is a material term of our senior secured credit facility as the failure to comply with such financial covenant could result in an event of default in respect of the revolving credit facility (and such an event of default could, in turn, result in an event of default under the IndentureIndentures governing our 7 ³/₄% Senior Subordinated Notes and 5 ¹/₂% Senior Subordinated Notes).

In addition to the above, our management uses EBITDA As Defined to review and assess the performance of the management team in connection with employee incentive programs and to prepare its annual budget and financial projections. Moreover, our management uses EBITDA As Defined to evaluate acquisitions.

Although we use EBITDA and EBITDA As Defined as measures to assess the performance of our business and for the other purposes set forth above, the use of these non-GAAP financial measures as analytical tools has limitations, and you should not consider any of them in isolation, or as a substitute for analysis of our results of operations as reported in accordance with GAAP. Some of these limitations are:

Because of these limitations, EBITDA and EBITDA As Defined should not be considered as measures of discretionary cash available to us to invest in the growth of our business. Management compensates for these limitations by not viewing EBITDA or EBITDA As Defined in isolation and specifically by using other GAAP measures, such as net income, net sales and operating profit, to measure our operating performance. Neither EBITDA nor EBITDA As Defined is a measurement of financial performance under GAAP, and neither should be considered as an alternative to net income or cash flow from operations determined in accordance with GAAP. Our calculation of EBITDA and EBITDA As Defined may not be comparable to the calculation of similarly titled measures reported by other companies.

The information presented below should be read together with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated financial statements and accompanying notes included elsewhere herein.

The following table sets forth a reconciliation of net income to EBITDA and EBITDA As Defined:

The following table sets forth a reconciliation of net cash provided by operating activities to EBITDA and EBITDA As Defined:

ITEM 7.

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion of our financial condition and results of operations should be read together with “Selected Financial Data” and TD Group’s consolidated financial statements and the related notes included elsewhere in this report. The following discussion may contain predictions, estimates and other forward-looking statements that involve a number of risks and uncertainties, including those discussed under the heading entitled “Risk Factors” included elsewhere in this report. These risks could cause our actual results to differ materially from any future performance suggested below.

Overview

We believe we are a leading global designer, producer and supplier of highly engineered aircraft components for use on nearly all commercial and military aircraft in service today. Our business is well diversified due to the broad range of products we offer to our customers. Some of our more significant product offerings, substantially all of which are ultimately provided to end-users in the aerospace industry, include mechanical/electro-mechanical actuators and controls, ignition systems and engine technology, specialized pumps and valves, power conditioning devices, specialized AC/DC electric motors and generators, NiCad batteries and chargers, engineered latching and locking devices, rods and locking devices, engineered connectors and elastomers, cockpit security components and systems, specialized cockpit displays, aircraft audio systems, specialized lavatory components, seatbelts and safety restraints, engineered interior surfaces and lighting and control technology. Each of these product offerings is composed of many individual products that are typically customized to meet the needs of a particular aircraft platform or customer.

Long-term Sustainable Growth

For fiscal year 2011,2012, we generated net sales of $1,206.0$1,700.2 million, gross profit of $661.2$945.7 million or 54.8%55.6% of sales, and net income of $172.1$325.0 million. We believe we have achieved steady, long-term growth in sales and improvements in operating performance since our formation in 1993 due to our competitive strengths and through execution of our value-driven operating strategy. More specifically, focusing our businesses on our value-driven operating strategy of obtaining profitable new business, carefully controlling the cost structure and pricing our highly engineered value-added products to fairly reflect the value we provide and the resources required to do so has historically resulted in improvements in gross profit and income from operations over the long term.

Our selective acquisition strategy has also contributed to the growth of our business. The integration of certain acquisitions into our existing businesses combined with implementing our proven operating strategy has historically resulted in improvements of the financial performance of the acquired business.

Our key competitive strengths and the elements of our business strategy are set forth in more detail below.

We believe our key competitive strengths include:

Large and Growing Installed Product Base with Aftermarket Revenue Stream.We provide components to a large and growing installed base of aircraft to which we supply aftermarket products. We estimate that our products are installed on approximately 70,000 commercial transport, regional transport, military and general aviation fixed wing turbine aircraft and rotary wing aircraft.

Diversified Revenue Base.We believe that our diversified revenue base reduces our dependence on any particular product, platform or market channel and has been a significant factor in maintaining our financial performance. Our products are installed on almost all of the major commercial aircraft platforms now in production. We expect to continue to develop new products for military and commercial applications.

Significant Barriers to Entry. We believe that the niche nature of our markets, the industry’s stringent regulatory and certification requirements, the large number of products that we sell and the investments necessary to develop and certify products create barriers to entry for potential competitors.

Our business strategy is made up of two key elements: (1) a value-driven operating strategy focused around our three core value drivers and (2) a selective acquisition strategy.

Value-Driven Operating Strategy.Our three core value drivers are:

Selective Acquisition Strategy.We selectively pursue the acquisition of proprietary aerospace component businesses when we see an opportunity to create value through the application of our three core value-driven operating strategies. The aerospace industry, in particular, remains highly fragmented, with many of the companies in the industry being small private businesses or small non-core operations of larger businesses. We have significant experience among our management team in executing acquisitions and integrating acquired businesses into our company and culture. As of the date of this report, we have successfully acquired and integrated 3439 businesses and/or product lines since our formation in 1993. Many of these acquisitions have been integrated into an existing TransDigm production facility, which enables a higher production capacity utilization, which in turn improves gross profit levels due to the ability to spread the fixed manufacturing overhead costs over higher production volume.

Public Offerings

On March 20, 2006 and May 25, 2007, certain stockholders of TD Group (including certain members of our management) sold an aggregate of 11.5 million and 12.6 million shares of TD Group’s common stock, respectively, in public offerings at prices of $21.00 and $35.25 per share. TD Group did not offer any shares of its common stock for sale in the public offerings and TD Group did not receive any of the proceeds from the sale of such shares by the selling stockholders. As a result of the initial public offering, TD Group’s common stock is publicly traded on the New York Stock Exchange under the ticker symbol “TDG.”

Certain Acquisitions and Divestitures

Aero-Instruments Co., LLC

On September 17, 2012, TransDigm Inc. acquired all of the outstanding equity interests in Aero-Instruments Co., LLC (“Aero-Instruments”), for approximately $34.7 million in cash, subject to adjustments based on the level of working capital as of the closing date of the acquisition. Aero-Instruments designs and manufactures highly engineered air data sensors including pitot probes, pitot-static probes, static pressure ports, angle of attack, temperature sensors and flight test equipment for use primarily in the business jet and helicopter markets. These products fit well with TransDigm’s overall business direction. The Company is in the process of obtaining information to value certain tangible and intangible assets of Aero-Instruments, and therefore the consolidated financial statements at September 30, 2012 reflect a preliminary purchase price allocation for the business.

AmSafe Global Holdings, Inc. Acquisition

On February 15, 2012, TransDigm Inc. acquired all of the outstanding stock of AmSafe Global Holdings, Inc. (“AmSafe”), for approximately $749.7 million in cash, which includes a purchase price adjustment of $0.5 million paid in the third quarter of fiscal 2012. AmSafe is a leading supplier of innovative, highly engineered and proprietary safety and restraint equipment used primarily in the global aerospace industry. These products fit well

with TransDigm’s overall business direction. The distribution business acquired as part of AmSafe was sold on August 16, 2012 for approximately $17.7 million in cash, subject to adjustments based on the level of working capital as of the closing date of the sale. The Company is in the process of obtaining information to value certain tangible and intangible assets of AmSafe, and therefore the consolidated financial statements at September 30, 2012 reflect a preliminary purchase price allocation for the business.

Harco Laboratories Acquisition

On December 9, 2011, TransDigm Inc. acquired all of the outstanding stock of Harco Laboratories, Incorporated (“Harco”), for approximately $83.3 million in cash, which includes a purchase price adjustment of $0.4 million paid in the second quarter of fiscal 2012. Harco designs and manufactures highly engineered thermocouples, sensors, engine cable assemblies and related products for commercial aircraft. These products fit well with TransDigm’s overall business direction. The Company is in the process of obtaining information to value certain tangible and intangible assets of Harco, and therefore the consolidated financial statements at September 30, 2012 reflect a preliminary purchase price allocation for the business.

Schneller Holdings Acquisition

On August 31, 2011, TransDigm Inc. acquired all of the outstanding equity interests in Schneller Holdings LLC (“Schneller”) for approximately $288.5$288.6 million in cash, subject to adjustments based onwhich includes a purchase price adjustment of $1.0 million paid in the levelfirst quarter of working capital as of the closing date of the acquisition.fiscal 2012. Schneller designs and manufactures proprietary, highly engineered laminates, thermoplastics, and non-textile flooring for use primarily on side walls, lavatories, galleys, bulkheads and cabin floors for commercial aircraft. These products fit well with TransDigm’s overall business direction. The Company is in the process of obtaining information to value certain tangible and intangible assets of Schneller, and therefore the consolidated financial statements at September 30, 2011 reflect a preliminary purchase price allocation for the business.

Talley Actuation Acquisition

On December 31, 2010, AeroControlex Group, Inc., a wholly owned subsidiary of TransDigm Inc., acquired the actuation business of Telair International Inc. (“Talley Actuation”), a wholly-owned subsidiary of Teleflex Incorporated, for approximately $93.6 million in cash, which includes a purchase price adjustment of $0.3 million received in the third quarter of fiscal 2011. Talley Actuation manufactures proprietary, highly engineered electro-mechanical products and other components for commercial and military aircraft. These products fit well with TransDigm’s overall business direction.

McKechnie Aerospace Holdings, Inc. Acquisition

On December 6, 2010, TransDigm Inc. acquired all of the outstanding stock of McKechnie Aerospace Holdings Inc. (“McKechnie Aerospace”), for approximately $1.27 billion in cash, which includes a purchase price adjustment of $0.3 million paid in the third quarter of fiscal 2011. McKechnie Aerospace, through its subsidiaries, is a leading global designer, producer and supplier of aerospace components, assemblies and subsystems for commercial aircraft, regional/business jets, military fixed wing and rotorcraft. Some of the businesses acquired as part of McKechnie Aerospace have since been divested (see below). The remaining products fit well with TransDigm’s overall business direction.

Semco Instruments Acquisition

On September 3, 2010, TransDigm Inc. acquired all of the outstanding capital stock of Semco Instruments, Inc. (“Semco”) for approximately $73.6 million in cash, which includes a purchase price adjustment of $3.0 million paid in the first quarter of fiscal 2011. Semco is a designer and manufacturer of proprietary, highly engineered components for all major turbo-prop, turbo-fan, and turbo-shaft engines, which are primarily used on helicopters, business jets and selected regional airplanes. These products fit well with TransDigm’s overall business direction.

Dukes Aerospace Acquisition

On December 2, 2009, Dukes Aerospace, Inc., a wholly owned subsidiary of TransDigm Inc., acquired substantially all of the aerospace-related assets of Dukes, Inc. and GST Industries, Inc. (collectively “Dukes Aerospace”) for approximately $95.5 million in cash, which includes a purchase price adjustment of $0.2 million received in the third quarter of fiscal 2011. Dukes Aerospace is a supplier of proprietary, highly engineered components primarily to the business jet, regional jet, and military aerospace markets, along with commercial and military helicopter markets. The products are comprised primarily of highly engineered valves and certain pumps, solenoids and related components. These products fit well with TransDigm’s overall business direction.

Woodward HRT Product Line Acquisition

On August 10, 2009, AeroControlex Group, Inc., a wholly owned subsidiary of TransDigm Inc., acquired certain product line assets of Woodward HRT, Inc., a subsidiary of Woodward Governor Company (“Woodward HRT product line”) for approximately $48.7 million in cash, which includes a purchase price adjustment of $0.7 million paid in the second quarter of fiscal 2010. The product line comprises a range of highly engineered fuel and pneumatic valves and surge suppressors, the majority of which are used on military rotary and fixed wing aircraft, all of which fit well with TransDigm’s overall business direction. Woodward Governor had recently acquired this business as part of its acquisition of HR Textron, Inc.

Acme Aerospace Acquisition

On July 24, 2009, TransDigm Inc. acquired all of the outstanding capital stock of Acme Aerospace, Inc. (“Acme”) for approximately $40.9 million in cash, which includes a purchase price adjustment of $0.2 million paid in the first quarter of fiscal 2010. Acme is a designer and manufacturer of proprietary, highly engineered components to the commercial aerospace industry, comprising primarily fibrous nickel cadmium main ship batteries, battery chargers, battery back-up systems and power conversion equipment. These products fit well with TransDigm’s overall business direction.

Aircraft Parts Corporation Acquisition

On December 16, 2008, TransDigm Inc. acquired all of the outstanding capital stock of Aircraft Parts Corporation (“APC”) for approximately $66.9 million in cash, net of a purchase price adjustment of $0.7 million received in the first quarter of fiscal 2010. APC is a designer and manufacturer of starter generators, generator control units and related components for turbine engines, all of which fit well with TransDigm’s overall business direction.

Aero Quality Sales Divestiture

On April 7, 2011, the Company completed the divestiture of Aero Quality Sales (“AQS”) to Satair A/S for approximately $31.8 million in cash, which includes a $1.8 million working capital adjustment received in the third quarter of fiscal 2011. AQS, which was acquired as part of the McKechnie Aerospace acquisition, is a distributor and service center of aircraft batteries and battery support equipment. The Company’s Chairman and Chief Executive Officer, W. Nicholas Howley was a director of Satair A/S from 2006 through October 2011. Mr. Howley discusseddisclosed his relationship to Satair A/S to the Company’s board of directors and abstained from the related vote.

Fastener Business Divestiture

On March 9, 2011, the Company completed the divestiture of its fastener business for approximately $239.6 million in cash, subject to adjustments based on the level of working capital as of the closing date.cash. This business, which was acquired as part of the McKechnie Aerospace acquisition, is made up of Valley-Todeco, Inc. and Linread Ltd. The business designs and manufactures fasteners, fastening systems and bearings for commercial, military and general aviation aircraft.

Recent Development

Agreement to Acquire Harco LaboratoriesGoodrich Pump & Engine Control Systems

On November 8, 2011,October 25, 2012, the Company entered into a definitive agreement to acquire Harco Laboratories, Incorporatedthe assets of the Goodrich Pump & Engine Control Systems business (“Harco”GPECS”) for approximately $84$236 million in cash. The acquisition, which is subject to review underapproval by the Hart-Scott-Rodino ActU.S. Department of Justice and other customary closing conditions,the European Commission, is expected to close duringlate in the first quarter of fiscal 2012. Harco designs andcurrent calendar year or early in 2013. GPECS manufactures proprietary, highly engineered thermocouples, sensors, engine cable assembliesaerospace fuel systems for the business jet, helicopter, military and related products primarily for major commercial aircraft.marketplace.

EBITDA and EBITDA As Defined

The following table sets forth a reconciliation of net income to EBITDA and EBITDA As Defined:

		Fiscal Years Ended September 30,
		2012				2011
		(in thousands)
Net income		$	324,969			$	172,134
Less income from discontinued operations			—				19,909
Income from continuing operations			324,969				152,225
Adjustments:
Depreciation and amortization expense			68,227				60,460
Interest expense, net			211,906				185,256
Income tax provision			162,900				77,200
EBITDA, excluding discontinued operations(1)			768,002				475,141
Adjustments:
Inventory purchase accounting adjustments(2)			12,882				18,073
Acquisition integration costs(3)			7,896				11,821
Acquisition transaction-related expenses(4)			5,880				2,817
Non-cash compensation costs(5)			22,151				12,568
Acquisition earn-out adjustments(6)			(5,000	)			(3,000	)
Other acquisition accounting adjustments			(2,792	)			—
Refinancing costs(7)			—				72,454
EBITDA As Defined(1)		$	809,019			$	589,874