**Date Posted:** 2025-06-27 **Country:** United States of America **Location:** 01: Building 01 Windsor Locks One Hamilton Road, Windsor Locks, CT, 06096 USA **Position Role Type:** Hybrid **U.S. Citizen, U.S. Person, or Immigration Status Requirements:** This job requires a U.S. Person. A U.S. Person is a lawful permanent resident as defined in 8 U.S.C. 1101(a)(20) or who is a protected individual as defined by 8 U.S.C. 1324b(a)(3). U.S. citizens, U.S. nationals, U.S. permanent residents, or individuals granted refugee or asylee status in the U.S. are considered U.S. persons. For a complete definition of “U.S. Person” go here: https://www.ecfr.gov/current/title-22/chapter-I/subchapter-M/part-120/subpart-C/section-120.62 **Security Clearance:** None/Not Required Collins Aerospace is looking for a Senior Principal Engineer to lead thermal fluid design for our Engine Control Systems (ECS) powering the next generation of aircraft. In this high-impact role, you'll shape the performance of systems like pumps, valves, and controls that keep engines running efficiently. You'll work alongside a top-tier engineering team and have a direct line to customers, suppliers, and product leadership. **What You Will Do** + Lead steady-state and transient thermal analyses on pumps, valves, electronics, heat exchangers, and more, using both analytical models and real-world test data + Plan, estimate, and execute complex aerodynamic and thermal designs across multiple aircraft programs + Analyze and improve systems such as Engine Bleed Air, Environmental Control, Air Distribution, Liquid & Vapor Cycle, and Inerting Systems + Develop and validate design changes based on heat transfer and fluid dynamics considerations + Document methods, results, processes, and procedures clearly and formally + Coach, delegate, and review work across a team of engineers + Communicate across disciplines and with customers, influencing design decisions and driving strategic direction + Contribute to new technologies, product strategies, and engineering standards that support long-term business goals **Qualifications You Must Have** + Requires a degree in Science, Technology, Engineering or Mathematics (STEM) and minimum 10 years prior relevant experience or an Advanced Degree in a related field and minimum 7 years of experience **Qualifications We Prefer** + M.S. in Mechanical or Aerospace Engineering + Hands-on experience with Star CCM+ or similar CFD/thermal simulation tools + Experience guiding product development from concept through qualification + Strong technical expertise in thermal fluids, aerodynamics, and heat transfer, and experience performing Computational Fluid Dynamics (CFD) analysis + Demonstrated ability to work effectively across cross-functional teams + Exceptional communication, collaboration, and influencing skills at all organizational levels + Proven experience leading engineering efforts in complex aerospace systems **What We Offer** Some of our competitive benefits packages include:  · Medical, dental, and vision insurance · Three weeks of vacation for newly hired employees · Generous 401(k) plan that includes employer matching funds and separate employer retirement contribution, including a Lifetime Income Strategy option · Tuition reimbursement program · Student Loan Repayment Program · Life insurance and disability coverage · Optional coverages you can buy pet insurance, home and auto insurance, additional life and accident insurance, critical illness insurance, group legal, ID theft protection · Birth, adoption, parental leave benefits · Ovia Health, fertility, and family planning · Adoption Assistance          · Autism Benefit · Employee Assistance Plan, including up to 10 free counseling sessions · Healthy You Incentives, wellness rewards program · Doctor on Demand, virtual doctor visits · Bright Horizons, child and elder care services · Teladoc Medical Experts, second opinion program ·  And more!  Eligible for relocation **Learn More & Apply Now!** We make modern flight possible for millions of travelers and our military every second.  Our major product lines are on-board virtually every aircraft flying. Be it keeping passengers safe with our emergency power generation systems or creating a positive in flight experience through reliable cabin pressure controls and quieter engines, Power & Controls focuses on delivering a best-in-class experience to our customers. We hire the top people in the industry. Their ideas drive our performance, and their integrity keeps our customers happy. Join us as we take flight! *Please ensure the role type (defined below) is appropriate for your needs before applying to this role. **Hybrid** : Employees who are working in Hybrid roles will work regularly both onsite and offsite. Ratio of time working onsite will be determined in partnership with your leader. At Collins, the paths we pave together lead to limitless possibility. And the bonds we form – with our customers and with each other -- propel us all higher, again and again. Apply now and be part of the team that’s redefining aerospace, every day. The salary range for this role is 124,000 USD - 250,000 USD. The salary range provided is a good faith estimate representative of all experience levels. RTX considers several factors when extending an offer, including but not limited to, the role, function and associated responsibilities, a candidate’s work experience, location, education/training, and key skills. Hired applicants may be eligible for benefits, including but not limited to, medical, dental, vision, life insurance, short-term disability, long-term disability, 401(k) match, flexible spending accounts, flexible work schedules, employee assistance program, Employee Scholar Program, parental leave, paid time off, and holidays. Specific benefits are dependent upon the specific business unit as well as whether or not the position is covered by a collective-bargaining agreement. Hired applicants may be eligible for annual short-term and/or long-term incentive compensation programs depending on the level of the position and whether or not it is covered by a collective-bargaining agreement. Payments under these annual programs are not guaranteed and are dependent upon a variety of factors including, but not limited to, individual performance, business unit performance, and/or the company’s performance. This role is a U.S.-based role. If the successful candidate resides in a U.S. territory, the appropriate pay structure and benefits will apply. RTX anticipates the application window closing approximately 40 days from the date the notice was posted. However, factors such as candidate flow and business necessity may require RTX to shorten or extend the application window. _RTX is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability or veteran status, or any other applicable state or federal protected class. RTX provides affirmative action in employment for qualified Individuals with a Disability and Protected Veterans in compliance with Section 503 of the Rehabilitation Act and the Vietnam Era Veterans’ Readjustment Assistance Act._ **Privacy Policy and Terms:** Click on this link (http://www.rtx.com/privacy/Job-Applicant-Privacy-Notice) to read the Policy and Terms Raytheon Technologies is An Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability or veteran status, age or any other federally protected class.