Item 1. BUSINESS

The Company

TransDigm Inc. was formed in 1993 in connection with a leveraged buyout transaction. TD Group was formed in 2003 to facilitate a leveraged buyout of TransDigm Inc. The Company was owned by private equity funds until its initial public offering in 2006. TD Group’s common stock is publicly traded on the New York Stock Exchange, or NYSE, under the ticker symbol “TDG.”

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 about 90% of our net sales for fiscal year 2018 were generated by proprietary products. In addition, for fiscal year 2018, we estimate that we generated about 80% 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 25 to 30 years. A typical platform can be produced for 20 to 30 years, giving us an estimated product life cycle in excess of 50 years. We estimate that approximately 60% of our net sales in fiscal year 2018 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, databus and power controls, cockpit security components and systems, specialized cockpit displays, aircraft audio systems, specialized lavatory components, seat belts and safety restraints, engineered interior surfaces and related components, lighting and control technology, military personnel parachutes, high performance hoists, winches and lifting devices, and cargo loading, handling and delivery systems.

Segments

The Company’s businesses are organized and managed in three reporting segments: Power & Control, Airframe and Non-aviation.

The Power & Control segment includes operations that primarily develop, produce and market systems and components that predominately provide power to or control power of the aircraft utilizing electronic, fluid, power and mechanical motion control technologies. Major product offerings 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, databus and power controls, high performance hoists, winches and lifting devices and cargo loading and handling systems. Primary customers of this segment are engine and power system and subsystem suppliers, airlines, third party maintenance suppliers, military buying agencies and repair depots. Products are sold in the OEM and aftermarket market channels.

The Airframe segment includes operations that primarily develop, produce and market systems and components that are used in non-power airframe applications utilizing airframe and cabin structure technologies. Major product offerings include engineered latching and locking devices, rods and locking devices, engineered connectors and elastomers, cockpit security components and systems, aircraft audio systems, specialized lavatory components, seat belts and safety restraints, engineered interior surfaces and related components, lighting and control technology, military personnel parachutes and cargo delivery systems. Primary customers of this segment are airframe manufacturers and cabin system suppliers and subsystem suppliers, airlines, third party maintenance suppliers, military buying agencies and repair depots. Products are sold in the OEM and aftermarket market channels.

The Non-aviation segment includes operations that primarily develop, produce and market products for non-aviation markets. Major product offerings include seat belts and safety restraints for ground transportation applications, mechanical/electro-mechanical actuators and controls for space applications, and refueling systems for heavy equipment used in mining, construction and other industries. Primary customers of this segment are off-road vehicle suppliers and subsystem suppliers, child restraint system suppliers, satellite and space system suppliers and manufacturers of heavy equipment used in mining, construction and other industries.

For financial information about our segments, see Note 16, “Segments,” to the consolidated financial statements included herein, which is incorporated by reference.

Pending Acquisition of Esterline Technologies Corporation

On October 9, 2018, the Company entered into a merger agreement with Esterline Technologies Corporation (“Esterline”), under which the Company agreed to acquire Esterline. Under the terms of the merger agreement, the Company will purchase each share of Esterline common stock outstanding for $122.50 per share in cash. TransDigm anticipates that the total transaction value will be approximately $4 billion, representing the $122.50 price paid per share for common stock outstanding plus existing debt. The Company expects the acquisition to be financed primarily through existing cash on hand and the incurrence of new term loans. In connection with the merger agreement, the Company entered into a commitment letter for a senior secured term facility up to $3.7 billion. The actual amount and timing of the new senior secured term facility is subject to the closing of the Esterline acquisition and the cash on hand at that time. The Company currently expects that the merger will be completed in 2019, subject to approval of Esterline’s shareholders, as well as other customary closing conditions, including the receipt of required regulatory approvals.

For further details on the acquisitions and divestiture that occurred during fiscal 2018, refer to Note 2, “Acquisitions and Divestitures,” to the consolidated financial statements included herein, which is incorporated by reference.

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 business unit manager to certain products. Each business unit 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 business unit 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 business unit 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 serve as a primary customer contact with certain smaller accounts. Our major distributors are Aviall, Inc. (a subsidiary of The Boeing Company) and Satair A/S (a subsidiary of Airbus S.A.S.).

Manufacturing and Engineering

We maintain approximately 80 manufacturing facilities. Most of our manufacturing facilities are 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 accounting and reporting, 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 expenses and research and development costs are recorded in selling and administrative expenses in our consolidated statements of income. The aggregate of engineering expense and research and development expense represents approximately 8% of our operating units’ aggregate costs, or approximately 4% of our consolidated net sales for fiscal year 2018. 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 (“FAA”) and OEM requirements. We perform a variety of testing procedures as required by our customers, such as testing under different temperature, humidity and altitude levels, flammability testing, 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. Refer to Note 3, “Summary of Significant Accounting Policies,” to the consolidated financial statements included herein with respect to total costs of research and development, which is incorporated by reference.

Customers

We predominantly serve customers in the commercial, regional, business jet and general aviation aftermarket, which accounts for approximately 36% of total sales; the commercial aerospace OEM market, comprising large commercial transport manufacturers and regional and business jet manufacturers, which accounts for approximately 24% of total sales; and the defense market, which accounts for approximately 35% of total sales. Non-aerospace sales comprise approximately 5% of our total sales.

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, 2018, Airbus S.A.S. (which includes Satair A/S, a distributor of commercial aftermarket parts to airlines throughout the world) accounted for approximately 11% of our net sales and The Boeing Company (which includes Aviall, Inc., also a distributor of commercial aftermarket parts to airlines throughout the world) accounted for approximately 10% of our net sales. Our top ten customers for fiscal year 2018 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 (including the 737MAX), 747, 767, 777 and 787, the Airbus A220 (previously known as the Bombardier CSeries), A320 family (including neo), A330, A350 and A380, the Bombardier CRJs, Q400/Dash-8 aircraft, Challenger and Learjets, the Embraer regional and business jets, the Cessna Citation family, the Gulfstream aircraft family, the Dassault aircraft family, the HondaJet and the ATR42/72 turboprop. Military platforms include aircraft such as the Boeing AH-64 Apache, CH-47, C-17, F-15, F-18, KC46 Tanker, P-8 and V-22, the Airbus A400M, the Lockheed Martin C-130J, F-16 and F-35 Joint Strike Fighter, UH-60 Blackhawk helicopter, the Northrop Grumman E-2C Hawkeye, the General

Atomics Predator Drone and the Raytheon Patriot Missile. We have been awarded numerous contracts for the development of engineered products for production on the Airbus A330neo, the Boeing 777x, the Bombardier Global 7500/8000, the Embraer E2, the Mitsubishi Regional Jet and the Sikorsky S-97 and JMR helicopter.

The markets in which we sell our products are, to varying degrees, cyclical and have experienced upswings and downturns. The demand for our commercial 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, the percentage of the worldwide fleet that is in warranty, and airline profitability. The demand for defense products is specifically dependent on government budget trends, military campaigns and political pressures.

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 may create disincentives for potential new competitors for certain products. If 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 the availability, dependability and safety of our products 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; (2) terminate existing contracts; (3) reduce the value of existing contracts; (4) audit our contract-related costs and fees, including allocated indirect costs; (5) control and potentially prohibit the export of our products; and (6) seek repayment of contract related payments under certain circumstances. Violations of government procurement laws could result in civil or criminal penalties.

Governmental Regulation

The commercial aircraft component industry is highly regulated by 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, our businesses are subject to many other laws and requirements typically applicable to manufacturers and exporters. Without limiting the foregoing, sales of many of our products that will be used on aircraft owned by foreign entities are subject to compliance with export control laws and the manufacture of our products and the operations of our businesses, including the disposal of hazardous wastes, are subject to compliance with applicable environmental laws.

Market Channels

The commercial aerospace industry, including the aftermarket and OEM market, is impacted by the health of the global economy and geo-political events around the world. The commercial aerospace industry has shown strength with increases in revenue passenger miles, or RPMs, since 2010, and positive growth continued through 2018 with increases in RPMs, as well as the growth in the large commercial OEM sector (aircraft with 100 or more seats) with order announcements by The Boeing Company and Airbus S.A.S. leading to planned increases in production. The 2019 leading indicators and industry consensus suggest a continuation of current trends in the commercial transport market sector supported by continued RPM growth and increases in production at the OEM level.

The defense aerospace market is dependent on government budget constraints, the timing of orders, political pressures and the extent of global conflicts. It is not necessarily affected by general economic conditions that affect the commercial aerospace industry.

Our presence in both the commercial aerospace and military sectors of the aerospace industry may mitigate the impact on our business of any specific industry risk. We service a diversified customer base in the commercial and military aerospace industry, and we provide components to a diverse installed base of aircraft, which mitigates our exposure to any individual airframe platform. At times, declines in sales in one channel have been offset by increased sales in another channel. However, due to differences between the profitability of our products sold to OEM and aftermarket customers, variation in product mix can cause variation in gross margin.

There are many short-term factors (including inventory corrections, unannounced changes in order patterns, strikes and mergers and acquisitions) that can cause short-term disruptions in our quarterly shipment patterns as compared to previous quarters and the same periods in prior years. As such, it can be difficult to determine longer-term trends in our business based on quarterly comparisons. To normalize for short-term fluctuations, we tend to look at our performance over several quarters or years of activity rather than discrete short-term periods.

There are also fluctuations in OEM and aftermarket ordering and delivery requests from quarter-to-quarter, as well as variations in product mix from quarter-to-quarter, that may cause positive or negative variations in gross profit margins since commercial aftermarket sales have historically produced a higher gross margin than sales to commercial OEMs. Again, in many instances these are timing events between quarters and must be balanced with macro aerospace industry indicators.

Commercial Aftermarket

The key growth factors in the commercial aftermarket include worldwide RPMs and the size and activity level of the worldwide fleet of aircraft and the percentage of the fleet that is in warranty.

Commercial OEM Market

The commercial transport market sector, the largest sector in the commercial OEM market, grew modestly during 2018. Our commercial transport OEM shipments and revenues generally run ahead of the Boeing and Airbus airframe delivery schedules. As a result and consistent with prior years, our fiscal 2019 shipments will be a function of, among other things, the estimated 2019 and 2020 commercial airframe production rates. We have been experiencing increased sales in the large commercial OEM sector (aircraft with 100 or more seats) driven by an increase in production by The Boeing Company and Airbus S.A.S tied to previous order announcements. Industry consensus indicates this production increase will continue in 2019 and 2020, though the growth may continue to moderate and begin to flatten.

Defense

Our military business fluctuates from year to year, and is dependent, to a degree, on government budget constraints, the timing of orders and the extent of global conflicts. For a variety of reasons, the military spending outlook is very uncertain. For planning purposes we assume that military related sales of our types of products to be flat in future years over the recent high levels.

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. Most of our 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, 2018, the Company estimated its sales order backlog at $2,026 million compared to an estimated sales order backlog of $1,669 million as of September 30, 2017. The increase in estimated sales order backlog is primarily due to organic growth in the commercial and defense markets and growth from acquisitions. The majority of the purchase orders outstanding as of September 30, 2018 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, 2018 may not necessarily represent the actual amount of shipments or sales for any future period.

Foreign Operations

Although we manufacture a significant portion of our products in the United States, we manufacture some products in Belgium, China, Germany, Hungary, Japan, Malaysia, Mexico, Norway, Sri Lanka, Sweden and the United Kingdom. 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.

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. Certain facilities and third-party sites utilized by 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. For information regarding environmental accruals, see Note 14, “Environmental Liabilities,” to the consolidated financial statements included herein, which is incorporated by reference.

Employees

As of September 30, 2018, we had approximately 10,100 full-time, part-time and temporary employees. Approximately 10% of our full-time and part-time employees were represented by labor unions. Collective bargaining agreements between us and these labor unions expire at various dates ranging from December 2018 to May 2022. We consider our relationship with our employees generally to be satisfactory.

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. In addition, the Company’s website allows investors and other interested persons to sign up to automatically receive e-mail alerts when news releases and financial information is posted on the website. The SEC also maintains a website, www.sec.gov, that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC. The content on any website referred to in this Annual Report on Form 10-K is not incorporated by reference into this Annual Report unless expressly noted.