Item 1. Business

General

United Technologies Corporation was incorporated in Delaware in 1934. UTC provides high technology products and services to the building systems and aerospace industries worldwide. Growth is attributable primarily to the internal development of our existing businesses and to acquisitions. The following description of our business should be read in conjunction with "Management’s Discussion and Analysis of Financial Condition and Results of Operations" in our 2017 Annual Report, including the information contained therein under the heading "Business Overview."

Our operations for the periods presented herein are classified into four segments: Otis, UTC Climate, Controls & Security, Pratt & Whitney, and UTC Aerospace Systems, with each segment comprised of groups of similar operating companies. References to each segment include the various operating companies established worldwide through which the operations for each segment are conducted.

Otis and UTC Climate, Controls & Security (collectively referred to as the "commercial businesses") serve customers in the commercial, government, infrastructure and residential property sectors and transport and refrigeration businesses worldwide. Pratt & Whitney and UTC Aerospace Systems (collectively referred to as the "aerospace businesses") primarily serve commercial and government customers in both the original equipment and aftermarket parts and services markets of the aerospace industry. For 2017, our commercial and industrial sales (generated principally by the commercial businesses) were approximately 50 percent of our consolidated sales, and our commercial aerospace sales and military aerospace sales (generated exclusively by our aerospace businesses) were approximately 37 percent and 13 percent, respectively, of our consolidated sales. International sales for 2017, including U.S. export sales, were 61% percent of our total segment sales.

This Form 10-K and our quarterly reports on Form 10-Q, current reports on Form 8-K and all amendments to those reports are available free of charge through the Investor Relations section of our Internet website (http://www.utc.com) under the heading "SEC Filings" as soon as reasonably practicable after these reports are electronically filed with, or furnished to, the Securities and Exchange Commission (SEC). Our SEC filings are also available for reading and copying at the SEC’s Public Reference Room at 100 F Street, NE, Washington, D.C. 20549. Information on the operation of the Public Reference Room may be obtained by calling the SEC at 1-800-SEC-0330. In addition, the SEC maintains an Internet site (http://www.sec.gov) containing reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC.

Description of Business by Segment

Each segment's business, including its principal products and services and other material developments and information, is described below. Segment financial data for the years 2015 through 2017, including financial information about foreign and domestic operations and export sales, appears in Note 19 to the Consolidated Financial Statements in our 2017 Annual Report. Segment sales as discussed below include intercompany sales, which are ultimately eliminated within the "Eliminations and other" category as reflected in the segment financial data in Note 19 to the Consolidated Financial Statements in our 2017 Annual Report. Similarly, total segment backlog as discussed below includes intercompany backlog, as well as fully-funded government orders.

Otis

Otis is the world’s largest elevator and escalator manufacturing, installation and service company. Otis designs, manufactures, sells and installs a wide range of passenger and freight elevators as well as escalators and moving walkways. In addition to new equipment, Otis provides modernization products to upgrade elevators and escalators as well as maintenance and repair services for both its products and those of other manufacturers. Otis serves customers in the commercial and residential property industries around the world. Otis sells directly to the end customer and through sales representatives and distributors.

Sales generated by Otis’ international operations were 73 percent and 75 percent of total Otis segment sales in 2017 and 2016, respectively. At December 31, 2017, Otis’ backlog was $16.2 billion as compared to $14.9 billion at December 31, 2016. Of the total Otis backlog at December 31, 2017, approximately $8.4 billion is expected to be realized as sales in 2018.

UTC Climate, Controls & Security

UTC Climate, Controls & Security is a leading provider of heating, ventilating, air conditioning (HVAC), refrigeration, fire, security and building automation products, solutions and services for residential, commercial, industrial and transportation applications. UTC Climate, Controls & Security provides a wide range of building systems, including cooling, heating, ventilation, refrigeration, fire and smoke detection, portable fire extinguishers, fire suppression, gas and flame safety, intruder alarms, access control systems, video surveillance and building control systems. UTC Climate, Controls & Security also provides a broad array of related building services, including audit, design, installation, system integration, repair, maintenance, and monitoring services.

UTC Climate, Controls & Security sells its HVAC and refrigeration solutions directly to end customers, including building contractors and owners, homeowners, transportation companies, retail stores and food service companies, and through joint ventures, manufacturer's representatives, distributors, wholesalers, dealers and retail outlets. These products and services are sold under the Carrier name and other brand names. UTC Climate, Controls & Security’s security and fire safety products and services are used by governments, financial institutions, architects, building owners and developers, security and fire consultants, homeowners and other end-users requiring a high level of security and fire protection for their businesses and residences. UTC Climate, Controls & Security provides its security and fire safety products and services under Chubb, Kidde and other brand names and sells directly to customers as well as through manufacturer's representatives, distributors, dealers, value-added resellers and retail distribution.

Certain UTC Climate, Controls & Security HVAC businesses are seasonal, and sales and service activity can be impacted by weather. UTC Climate, Controls & Security customarily offers its customers incentives to purchase products to ensure an adequate supply of its products in the distribution channels. The principal incentive program provides reimbursements to distributors for offering promotional pricing on UTC Climate, Controls & Security products.

Sales generated by UTC Climate, Controls & Security’s international operations, including U.S. export sales, were 55 percent of total UTC Climate, Controls & Security segment sales in each of 2017 and 2016. At December 31, 2017, UTC Climate, Controls & Security’s backlog was $4.4 billion as compared to $3.2 billion at December 31, 2016. Substantially all of the backlog at December 31, 2017 is expected to be realized as sales in 2018.

Pratt & Whitney

Pratt & Whitney is among the world’s leading suppliers of aircraft engines for the commercial, military, business jet and general aviation markets. Pratt & Whitney provides fleet management services and aftermarket maintenance, repair and overhaul services. Pratt & Whitney produces and develops families of large engines for wide- and narrow-body and large regional aircraft in the commercial market and for fighter, bomber, tanker and transport aircraft in the military market. Pratt & Whitney Canada (P&WC) is among the world's leading suppliers of engines powering general and business aviation, as well as regional airline, utility and military airplanes, and helicopters. Pratt & Whitney and P&WC also produce, sell and service auxiliary power units for commercial and military aircraft.

The development of new engines and improvements to current production engines present important growth opportunities. In view of the risks and costs associated with developing new engines, Pratt & Whitney has entered into collaboration arrangements in which revenues, costs and risks are shared with third parties. At December 31, 2017, the interests of third-party participants in Pratt & Whitney-directed commercial jet engine programs ranged from approximately 14 percent to 50 percent. UTC holds a 61 percent interest in the IAE International Aero Engines AG (IAE) collaboration with MTU Aero Engines AG (MTU) and Japanese Aero Engines Corporation (JAEC). Pratt & Whitney also holds a 59 percent program share interest in the International Aero Engines, LLC (IAE LLC) collaboration with MTU and JAEC. IAE LLC sells the PW1100G-JM engine for the Airbus A320neo aircraft and the PW1400G-JM engine for the Irkut MC-21 aircraft. In addition, Pratt &

Whitney has interests in other engine programs, including a 50 percent ownership interest in the Engine Alliance (EA), a joint venture with GE Aviation, which markets and manufactures the GP7000 engine for the Airbus A380 aircraft. Pratt & Whitney has entered into risk and revenue sharing arrangements with third parties for 40 percent of the products and services that Pratt & Whitney is responsible for providing to the EA. Pratt & Whitney accounts for its interests in the EA joint venture under the equity method of accounting. See Note 1 to the Consolidated Financial Statements in our 2017 Annual Report for a description of our accounting for collaborative arrangements.

Pratt & Whitney produces the PurePower PW1000G Geared TurboFan engine family, the first of which, the PW1100G-JM, entered into service in January 2016. The PurePower PW1000G engine has demonstrated a significant reduction in fuel burn and noise levels with lower environmental emissions and operating costs than current production engines. The PW1100G-JM engine is offered on the Airbus A320neo family of aircraft. PurePower PW1000G engine models also power Bombardier’s CSeries passenger aircraft. Additionally, the PurePower PW1000G engine models have been selected to power the new Mitsubishi Regional Jet, the new Irkut MC-21 passenger aircraft and Embraer’s E-Jet family of aircraft. The Irkut MC-21 and Embraer’s E-Jet family aircraft are scheduled to enter service in 2018. The Mitsubishi Regional Jet is scheduled to enter service in 2020. As previously disclosed, Gulfstream announced the selection of the PurePower PW 800 engine to exclusively power Gulfstream’s new G500 and G600 business jets scheduled to enter service in 2018. P&WC's PurePower PW 800 engine has also been selected to power the new Falcon business jet by Dassault Aviation. P&WC has developed and certified the PW210 engine family for helicopters manufactured by Sikorsky and Leonardo Helicopters. Pratt & Whitney continues to enhance its programs through performance improvement measures and product base expansion. The success of these aircraft and engines is dependent upon many factors, including technological accomplishments, program execution, aircraft demand, and regulatory approval. As a result of these factors, as well as the level of success of aircraft program launches by aircraft manufacturers and other conditions, additional investment in these engine programs may be required.

In 2017, Pratt & Whitney’s commercial products supported engine certification of the PW1200G and PW 1700G for the Mitsubishi Regional Jet and Embraer E190-E2 and E-195-E2, the first flight of the Irkut MC21. Pratt & Whitney Canada has developed and received European Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) Type Certifications for the PurePower PW800 turbofan engine for the Gulfstream G500 and G600 aircraft. Also during the year, the Pratt & Whitney F-135 program experienced the first engine delivery from the Japan Final Assembly and Check Out facility and the Israeli Air Force achieved initial operational capability for their F-35I ‘Adir’ fleet. The military business also supported FAR Part 25 aircraft certification for the Boeing Tanker KC-46A aircraft.

Pratt & Whitney is under contract with the U.S. Government's F-35 Joint Program Office to produce and sustain the F135 engine to power the single-engine F-35 Lightning II aircraft (commonly known as the Joint Strike Fighter) being produced by Lockheed Martin. The two F135 propulsion system configurations for the F-35A, F-35B and F-35C jets are used by the U.S. Air Force, U.S. Marine Corps and U.S. Navy, respectively. F135 engines are also used on F-35 aircraft purchased by Joint Strike Fighter partner countries and foreign military sales countries.

Pratt & Whitney’s products are sold principally to aircraft manufacturers, airlines and other aircraft operators, aircraft leasing companies and the U.S. and foreign governments. Pratt & Whitney’s products and services must adhere to strict regulatory and market-driven safety and performance standards. The frequently changing nature of these standards, along with the long duration of aircraft engine development, production and support programs, creates uncertainty regarding engine program profitability. Sales to Airbus (Pratt & Whitney’s largest customer by sales) were 38 percent and 34 percent of total Pratt & Whitney segment sales in 2017 and 2016, respectively, before taking into account discounts or financial incentives offered to customers. Sales to the U.S. Government were approximately 21 percent of total Pratt & Whitney segment sales in 2017 and 2016.

Sales generated by Pratt & Whitney’s international operations, including U.S. export sales, were 61 percent and 63 percent of total Pratt & Whitney segment sales in 2017 and 2016, respectively. At December 31, 2017, Pratt & Whitney’s backlog was $64.3 billion, including $6.0 billion of U.S. Government-funded contracts and subcontracts. At December 31, 2016, these amounts were $61.8 billion and $6.4 billion, respectively. Of the total Pratt & Whitney backlog at December 31, 2017, approximately $11.1 billion is expected to be realized as sales in 2018. Pratt & Whitney’s backlog includes certain contracts for which actual costs may ultimately exceed total sales. Pratt & Whitney’s backlog excludes orders for new commercial engines that have not yet received aviation authority engine certification. See Note 1 to the Consolidated Financial Statements in our 2017 Annual Report for a description of our accounting for long-term contracts, including a discussion of the impact of Accounting Standards Update 2014-09, Revenue from Contracts with Customers, on our revenue recognition and backlog accounting policies.

UTC Aerospace Systems

UTC Aerospace Systems is a leading global provider of technologically advanced aerospace products and aftermarket service solutions for aircraft manufacturers, airlines, regional, business and general aviation markets, military, space and

undersea operations. UTC Aerospace Systems’ product portfolio includes electric power generation, power management and distribution systems, air data and aircraft sensing systems, engine control systems, intelligence, surveillance and reconnaissance systems, engine components, environmental control systems, fire and ice detection and protection systems, propeller systems, engine nacelle systems, including thrust reversers and mounting pylons, interior and exterior aircraft lighting, aircraft seating and cargo systems, actuation systems, landing systems, including landing gear, wheels and brakes, and space products and subsystems. Aftermarket services include spare parts, overhaul and repair, engineering and technical support and fleet management solutions. UTC Aerospace Systems sells aerospace products to aircraft manufacturers, airlines and other aircraft operators, the U.S. and foreign governments, maintenance, repair and overhaul providers, and independent distributors. UTC Aerospace Systems’ largest customers are Boeing and Airbus with a combined 33 percent and 34 percent of total UTC Aerospace Systems segment sales in 2017 and 2016, respectively. Sales to the U.S. Government were 17 percent of total UTC Aerospace Systems segment sales in 2017 and 2016.

In 2017, UTC Aerospace Systems' products supported first flights of the Boeing 737MAX-9 and 787-10, Embraer E195-E2, COMAC C919, AirbusA330neo and Irkut MC21 aircraft. In addition, UTC Aerospace Systems' products supported the certification of the Airbus A350-1000, and the on-going certification efforts for the Gulfstream G500 and the Embraer E190-E2.

Significant product development activity continues, including major systems for the Embraer E175-E2 and KC390, the Mitsubishi Regional Jet and the Bombardier Global 7000/8000. UTC Aerospace Systems is also the operations support prime contractor for NASA’s space suit/life support system and produces environmental monitoring and control, life support, power management and distribution, and thermal control systems for the International Space Station and the Orion crew exploration vehicle.

Sales generated by UTC Aerospace Systems’ international operations, including U.S. export sales, were 56 percent of total UTC Aerospace Systems segment sales in each of 2017 and 2016. At December 31, 2017, UTC Aerospace Systems’ backlog was $13.9 billion, including $3.0 billion of U.S. Government-funded contracts and subcontracts. At December 31, 2016, these amounts were $12.7 billion and $2.4 billion, respectively. The 2016 amounts have been revised to present backlog balances on a basis consistent with the 2017 presentation. Of the total UTC Aerospace Systems backlog at December 31, 2017, approximately $7.8 billion is expected to be realized as sales in 2018. See Note 1 to the Consolidated Financial Statements in our 2017 Annual Report for a description of our accounting for long-term contracts, including a discussion of the impact of Accounting Standards Update 2014-09, Revenue from Contracts with Customers, on our revenue recognition and backlog accounting policies.

UTC's Pending Acquisition of Rockwell Collins

On September 4, 2017, we announced that we had entered into a merger agreement with Rockwell Collins, Inc. (Rockwell Collins), under which we agreed to acquire Rockwell Collins. Under the terms of the merger agreement, each Rockwell Collins shareowner will receive $93.33 per share in cash and a fraction of a share of UTC common stock equal to the quotient obtained by dividing $46.67 by the average of the volume-weighted average price per share of UTC common stock on the NYSE on each of the 20 consecutive trading days ending with the trading day immediately prior to the closing date (the “UTC Stock Price”), subject to adjustment based on a two-way collar mechanism as described below (the “Stock Consideration”). The cash and UTC stock payable in exchange for each such share of Rockwell Collins common stock are collectively the “Merger Consideration.” The fraction of a share of UTC common stock into which each such share of Rockwell Collins common stock will be converted is the “Exchange Ratio.” The Exchange Ratio will be determined based upon the UTC Stock Price. If the UTC Stock Price is greater than $107.01 but less than $124.37, the Exchange Ratio will be equal to the quotient of (i) $46.67 divided by (ii) the UTC Stock Price, which, in each case, will result in the Stock Consideration having a value equal to $46.67. If the UTC Stock Price is less than or equal to $107.01 or greater than or equal to $124.37, then a two-way collar mechanism will apply, pursuant to which, (x) if the UTC Stock Price is greater than or equal to $124.37, the Exchange Ratio will be fixed at 0.37525 and the value of the Stock Consideration will be greater than $46.67, and (y) if the UTC Stock Price is less than or equal to $107.01, the Exchange Ratio will be fixed at 0.43613 and the value of the Stock Consideration will be less than $46.67. On January 11, 2018, the merger was approved by Rockwell Collins' shareowners. We currently expect that the merger will be completed in the third quarter of 2018, subject to customary closing conditions, including the receipt of required regulatory approvals.

We anticipate that approximately $15 billion will be required to pay the aggregate cash portion of the Merger Consideration. We expect to fund the cash portion of the Merger Consideration through debt issuances and cash on hand. Additionally, we have entered into a $6.5 billion 364-day unsecured bridge loan credit agreement that would be funded only to the extent certain anticipated debt issuances are not completed prior to the completion of the merger. We expect to assume approximately $7 billion of Rockwell Collins' outstanding debt upon completion of the merger. To help manage the cash flow and liquidity impact resulting from the pending acquisition, we have, among other things, suspended share repurchases, excluding activity relating to our employee savings plans. As we continue to assess the impacts of the U.S. tax reform enacted on December 22, 2017, commonly referred to as the Tax Cuts and Jobs Act of 2017 (TCJA), future opportunities for

repatriation of our non-U.S. earnings, and accelerated de-leveraging, we may consider, in addition to investments in our operations, limited additional share repurchases to offset the effects of dilution related to our stock-based compensation programs - see Note 12 to the Consolidated Financial Statements in our 2017 Annual Report.

Rockwell Collins is a leader in aviation and high-integrity solutions for commercial and military customers and is globally recognized for its leading-edge avionics, flight controls, aircraft interior and data connectivity solutions. Upon completion of the transaction, Rockwell Collins and UTC Aerospace Systems will be integrated to create a new business unit named Collins Aerospace Systems. Kelly Ortberg, Rockwell Collins' current Chairman and Chief Executive Officer, is expected to assume the role of Chief Executive Officer of this new business unit, with David Gitlin, UTC Aerospace Systems' current President, serving as President and Chief Operating Officer of the unit.

Other Matters Relating to Our Business as a Whole

Competition and Other Factors Affecting Our Businesses

As worldwide businesses, our operations can be affected by a variety of economic, industry and other factors, including those described in this section, in "Management’s Discussion and Analysis of Financial Condition and Results of Operations" included in our 2017 Annual Report, in Item 1, "Cautionary Note Concerning Factors That May Affect Future Results," and in Item 1A, "Risk Factors" in this Form 10-K. Each business unit is subject to significant competition from a large number of companies in the U.S. and other countries, and each competes on the basis of price, delivery schedule, product performance and service.

Our aerospace businesses are subject to substantial competition from various domestic and foreign manufacturers, customers and companies that obtain regulatory agency approval to manufacture spare parts, with foreign companies sometimes receiving government research and development assistance, marketing subsidies and other assistance for certain of their commercial products beyond the assistance that may be available in the U.S. Customer selections of aircraft engines, components and systems can also have a significant impact on future sales of parts and services. In addition, the U.S. Government’s and other governments’ policies of purchasing parts from suppliers other than the original equipment manufacturer affect military spare parts sales. Significant elements of our aerospace businesses, such as spare parts sales for engines and aircraft in service, have short lead times. Therefore, backlog information may not be indicative of future demand. Additionally, our aerospace businesses' competitors may offer substantial discounts and other financial incentives, performance and operating cost guarantees, and participation in financing arrangements, in an effort to compete for the aftermarket associated with these products. For information regarding customer financing commitments, participation in guarantees of customer financing arrangements and performance and operating cost guarantees, primarily related to Pratt & Whitney, see Notes 5 and 17 to the Consolidated Financial Statements in our 2017 Annual Report. Pratt & Whitney’s major competitors in the sale of engines are GE Aviation, Honeywell, Safran Helicopter Engines, and CFM International.

Research and Development

Because changes in technology can have a significant impact on our operations and competitive position, we spend substantial amounts of our own funds on research and development. These expenditures, which are charged to expense as incurred, were $2.4 billion or 4.0 percent of total sales in 2017 and $2.3 billion or 4.1 percent of total sales in 2016 and 2015. We also perform research and development work under contracts funded by the U.S. Government and other customers. Costs incurred under this contract research and development, which is performed in our aerospace businesses, amounted to $1.5 billion in 2017, as compared to $1.4 billion in 2016 and $1.5 billion in 2015. These contract research and development costs include amounts that are expensed as incurred, through cost of products sold, and amounts that are capitalized into inventory to be subsequently recovered through production shipments. Total contract research and development costs of $1.5 billion, $1.4 billion and $1.6 billion were expensed through cost of products sold in 2017, 2016 and 2015, respectively.

U.S. Government Contracts

Contracting with the U.S. Government entails certain unique risks. U.S. Government contracts are subject to termination by the government, either for convenience or for default in the event of our failure to perform under the applicable contract. In the case of a termination for convenience, we would normally be entitled to reimbursement for our allowable costs incurred and termination costs. If terminated by the government as a result of our default, we could be liable for additional costs the government incurs in acquiring undelivered goods or services from another source and any other damages it suffers. Most of our U.S. Government sales are made under fixed-price type contracts, while approximately $1.8 billion or 3 percent of our total sales for 2017 were made under cost-reimbursement type contracts.

Our contracts with the U.S. Government are also subject to audits. Like many defense contractors, we have received audit reports, which recommend that certain contract prices should be reduced, or that certain payments should be delayed, refunded

or withheld to comply with various government regulations, including reports alleging that cost or pricing data we submitted in negotiation of the contract prices or cost accounting practices may not have conformed to government regulations. Some of these audit reports involved substantial amounts. We have made voluntary refunds in those cases we believe appropriate, have settled some allegations and, in some cases, continue to negotiate with the government and/or litigate. For further discussion of risks related to government contracting, Item 1A, "Risk Factors" and Item 3, "Legal Proceedings," in this Form 10-K and Note 18 to the Consolidated Financial Statements in our 2017 Annual Report.

Compliance with Environmental and Other Government Regulations

Our operations are subject to and affected by environmental regulation by federal, state and local authorities in the U.S. and regulatory authorities with jurisdiction over our foreign operations. We have incurred and will likely continue to incur liabilities under various government statutes for the cleanup of pollutants previously released into the environment. We do not anticipate that compliance with current provisions relating to the protection of the environment or that any payments we may be required to make for cleanup liabilities will have a material adverse effect upon our cash flows, competitive position, financial condition or results of operations. Environmental matters are further addressed in "Management’s Discussion and Analysis of Financial Condition and Results of Operations" and Notes 1 and 18 to the Consolidated Financial Statements in our 2017 Annual Report.

Most of the U.S. laws governing environmental matters include criminal provisions. If we were convicted of a violation of the federal Clean Air Act or Clean Water Act, the facility or facilities involved in the violation could be deemed ineligible to be used in performing any U.S. Government contract we are awarded until the Environmental Protection Agency thereafter certifies that the condition giving rise to the violation has been corrected.

In addition, we could be affected by future laws or regulations imposed in response to concerns over climate change. Changes in climate change concerns, or in the regulation of such concerns, including greenhouse gas emissions, could subject us to additional costs and restrictions, including compliance costs and increased energy and raw materials costs.

We conduct our businesses through subsidiaries and affiliates worldwide. Changes in legislation or government policies can affect our worldwide operations. For example, governmental regulation of refrigerants and energy efficiency standards and fire safety regulations are important to our UTC Climate, Controls & Security businesses, and elevator safety codes are important to the businesses of Otis, while government safety and performance regulations, restrictions on aircraft engine noise and emissions and government procurement practices can impact our aerospace businesses.

U.S. laws, regulations, orders, and other measures concerning the export or re-export of products, software, services and technology to, and other trade-related activities involving, non-U.S. countries and parties affect the operations of UTC and its affiliates.

For further discussion of risks related to environmental matters and other government regulations, see Item 1A, "Risk Factors" and Item 3, "Legal Proceedings," in this Form 10-K and Note 18 to the Consolidated Financial Statements in our 2017 Annual Report.

Intellectual Property and Raw Materials and Supplies

We maintain a portfolio of patents, trademarks, copyrights, trade secrets, licenses and franchises related to our businesses. While we believe we have taken reasonable measures to protect this portfolio, our efforts may not be sufficient. See Item 1A "Risk Factors" in this Form 10-K for further discussion of intellectual property matters.

We believe we have adequate sources for our purchases of materials, components, services and supplies used in our manufacturing. We work continuously with our supply base to ensure an adequate source of supply and to reduce costs. We pursue cost reductions through a number of mechanisms, including consolidating our purchases, reducing the number of suppliers, strategic global sourcing and using bidding competitions among potential suppliers. In some instances, we depend upon a single source of supply or participate in commodity markets that may be subject to allocations of limited supplies by suppliers. Like other users in the U.S., we are largely dependent upon foreign sources for certain raw materials requirements, such as cobalt, tantalum, chromium, rhenium and nickel. We have a number of ongoing programs to manage this dependence and the accompanying risk, including long-term agreements and the conservation of materials through scrap reclamation and new manufacturing processes. We believe that our supply management practices are based on an appropriate balancing of the foreseeable risks and the costs of alternative practices. Although at times high prices for some raw materials important to our businesses (for example, steel, copper, aluminum, titanium and nickel) have caused margin and cost pressures, we do not foresee near term unavailability of materials, components or supplies that would have a material adverse effect on our competitive position, results of operations, cash flows or financial condition. For further discussion of the possible effects of the cost and availability of raw materials on our business, see Item 1A, "Risk Factors" in this Form 10-K.

Employees and Employee Relations

At December 31, 2017, our total number of employees was approximately 205,000, of which approximately 67 percent represents employees based outside the U.S. During 2017, we negotiated or concluded 12 domestic collective bargaining agreements, the largest of which covered certain workers at Otis across the U.S. In 2018, numerous collective bargaining agreements are subject to renegotiation, the largest of which covers certain workers at UTC Aerospace Systems in Rockford, Illinois. Although some previous contract renegotiations have had a significant impact on our financial condition or results of operations, we do not anticipate that the renegotiation of these contracts in 2018 will have a material adverse effect on our competitive position, cash flows, financial condition or results of operations. For discussion of the effects of our restructuring actions on employment, see Item 1A, "Risk Factors" in this Form 10-K and under "Management’s Discussion and Analysis of Financial Condition and Results of Operations" and Note 13 to the Consolidated Financial Statements in our 2017 Annual Report.

For a discussion of other matters which may affect our competitive position, cash flows, financial condition or results of operations, including the risks of our international operations, see the further discussion under the headings "General" and "Description of Business by Segment" in this section, Item 1A, "Risk Factors" in this Form 10-K, and under "Management’s Discussion and Analysis of Financial Condition and Results of Operations" in our 2017 Annual Report.

Cautionary Note Concerning Factors That May Affect Future Results

This Form 10-K contains statements which, to the extent they are not statements of historical or present fact, constitute "forward-looking statements" under the securities laws. From time to time, oral or written forward-looking statements may also be included in other information released to the public. These forward-looking statements are intended to provide management’s current expectations or plans for our future operating and financial performance, based on assumptions currently believed to be valid. Forward-looking statements can be identified by the use of words such as "believe," "expect," "expectations," "plans," "strategy," "prospects," "estimate," "project," "target," "anticipate," "will," "should," "see," "guidance," "outlook", "confident" and other words of similar meaning in connection with a discussion of future operating or financial performance. Forward-looking statements may include, among other things, statements relating to future sales, earnings, cash flow, results of operations, uses of cash, share repurchases, tax rates and other measures of financial performance or potential future plans, strategies or transactions of United Technologies or the combined company following United Technologies’ pending acquisition of Rockwell Collins, the anticipated benefits of the pending acquisition, including estimated synergies, the expected timing of completion of the transaction and other statements that are not historical facts. All forward-looking statements involve risks, uncertainties and other factors that may cause actual results to differ materially from those expressed or implied in the forward-looking statements. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the U.S. Private Securities Litigation Reform Act of 1995. Such risks, uncertainties and other factors include, without limitation:

•

the effect of economic conditions in the industries and markets in which we and Rockwell Collins operate in the U.S. and globally and any changes therein, including financial market conditions, fluctuations in commodity prices, interest rates and foreign currency exchange rates, levels of end market demand in construction and in both the commercial and defense segments of the aerospace industry, levels of air travel, financial condition of commercial airlines, the impact of weather conditions and natural disasters and the financial condition of our customers and suppliers;

•	challenges in the development, production, delivery, support, performance and realization of the anticipated benefits of advanced technologies and new products and services;

•	the scope, nature, impact or timing of acquisition and divestiture activity, including the pending acquisition of Rockwell Collins, including among other things integration of acquired businesses into UTC's existing businesses and realization of synergies and opportunities for growth and innovation;

•	future levels of indebtedness, including indebtedness expected to be incurred by UTC in connection with the proposed Rockwell Collins acquisition, and capital spending and research and development spending, including in connection with the proposed Rockwell Collins acquisition;

•	future availability of credit and factors that may affect such availability, including credit market conditions and our capital structure;

•	the timing and scope of future repurchases of our common stock, which may be suspended at any time due to various factors, including market conditions and the level of other investing activities and uses of cash;

•	delays and disruption in delivery of materials and services from suppliers;

•	company and customer-directed cost reduction efforts and restructuring costs and savings and other consequences thereof;

•	new business and investment opportunities;

•	our ability to realize the intended benefits of organizational changes;

•	the anticipated benefits of diversification and balance of operations across product lines, regions and industries;

•	the outcome of legal proceedings, investigations and other contingencies;

•	pension plan assumptions and future contributions;

•	the impact of the negotiation of collective bargaining agreements and labor disputes;

•	the effect of changes in political conditions in the U.S. and other countries in which we and Rockwell Collins operate, including the effect of changes in U.S. trade policies or the U.K.'s pending withdrawal from the EU, on general market conditions, global trade policies and currency exchange rates in the near term and beyond; and

•	the effect of changes in tax (including the U.S. tax reform enacted on December 22, 2017 and is commonly referred to as the Tax Cuts and Jobs Act of 2017 (TCJA), environmental, regulatory (including among other things import/export) and other laws and regulations in the U.S. and other countries in which we and Rockwell Collins operate;

•	the ability of UTC and Rockwell Collins to receive the required regulatory approvals (and the risk that such approvals may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the merger) and to satisfy the other conditions to the closing of the proposed merger on a timely basis or at all;

•	the occurrence of events that may give rise to a right of one or both of UTC or Rockwell Collins to terminate the merger agreement, including in circumstances that might require Rockwell Collins to pay a termination fee of $695 million to UTC or $50 million of expense reimbursement;

•	negative effects of the announcement or the completion of the merger on the market price of UTC’s and/or Rockwell Collins’ common stock and/or on their respective financial performance;

•	the risks related to Rockwell Collins and UTC being restricted in their operation of their businesses while the merger agreement is in effect;

•	risks relating to the value of the UTC’s shares to be issued in connection with the proposed Rockwell merger, significant merger costs and/or unknown liabilities;

•	risks associated with third-party contracts containing consent and/or other provisions that may be triggered by the Rockwell merger agreement;

•	risks associated with merger-related litigation or appraisal proceedings; and

•	the ability of UTC and Rockwell Collins, or the combined company, to retain and hire key personnel.

In addition, this Form 10-K includes important information as to risks, uncertainties and other factors that may cause actual results to differ materially from those expressed or implied in the forward-looking statements. See the "Notes to Consolidated Financial Statements" under the heading "Note 18: Contingent Liabilities," the section titled "Management’s Discussion and Analysis of Financial Condition and Results of Operations" under the headings "Business Overview," "Results of Operations," "Liquidity and Financial Condition," and "Critical Accounting Estimates," and the section titled "Risk Factors." This Form 10-K also includes important information as to these factors in the "Business" section under the headings "General," "Description of Business by Segment" and "Other Matters Relating to Our Business as a Whole," and in the "Legal Proceedings" section. Additional important information as to these factors is included in our 2017 Annual Report in the section titled "Management’s Discussion and Analysis of Financial Condition and Results of Operations" under the headings "Restructuring Costs," "Environmental Matters" and "Governmental Matters." The forward-looking statements speak only as of the date of this report or, in the case of any document incorporated by reference, the date of that document. We undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law. Additional information as to factors that may cause actual results to differ materially from those expressed or implied in the forward-looking statements is disclosed from time to time in our other filings with the SEC.