JobsBoeing

Experienced or Senior Mechanical System Design Engineers

Boeing · Mascoutah, IL

Posted Sep 3, 2026 · We last checked this listing on Sep 20, 2026

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Likely interview questions for this role

Written from this job description, not a generic list. Each one notes what the interviewer is really checking.

Behavioral

Tell me about a time you had to develop or modify a component design for a fluid system, like a pump, valve, or heat exchanger, and it didn't meet requirements on first pass. What did you do?

depth of hands-on fluid systems experience and how they troubleshoot design failures

Describe a time you had to reconcile analysis results with test data that disagreed with each other. How did you figure out which one to trust?

rigor in validation and verification, and comfort challenging their own analysis

Give me an example of a design problem where the obvious solution wouldn't work because of weight, space, or integration constraints, and how you found another way.

ability to innovate under the tight physical constraints typical of aircraft subsystem design

Tell me about a time you worked under minimal direction on a design task with no clear precedent. What did you decide on your own, and when did you loop in your lead?

judgment about autonomy versus escalation, tied to the Level 4 'minimal direction' expectation

Technical

Walk me through a mechanical subsystem you designed from requirements through release, using 3-D CAD. What was the subsystem and what tools did you use?

whether the candidate has genuine end-to-end design ownership, not just isolated CAD tasks

How do you use NX and Teamcenter day to day, and have you run into any issues with data management or configuration control across a large team?

real fluency with the specific PLM and CAD tools rather than resume keyword familiarity

What thermal or modeling tools have you used, things like ANSYS Thermal Desktop, Matlab, Simulink, Amesim, or Flomaster, and can you give me an example of a problem you solved with one?

whether preferred tool experience is real or just listed

Tell me about the most complex requirements document you've had to write or interpret for an air vehicle subsystem. What made it hard?

ability to translate system-level needs into component-level requirements, a core Level 3/4 duty

Have you worked with Model Based Systems Engineering tools like Magic Systems of Systems Architect? Tell me about how you used it on a project.

actual MBSE exposure versus theoretical familiarity

What's your experience with landing gear, mechanisms, environmental cooling, or another one of these named subsystem areas, and which one do you know best?

matching candidate's actual subsystem depth against the specific domains this role covers

Situational

Say a supplier's test results come back and their component doesn't meet the spec you gave them. Walk me through how you'd handle that conversation and get the design back on track.

how they manage supplier relationships and hold technical ground without derailing the schedule

Imagine you're leading a design review and a structures engineer and a systems engineer disagree on where a mechanism should be located. How do you run that meeting?

cross-discipline coordination and leadership under conflicting technical priorities, relevant to senior-level scope

This role requires the ability to get a Secret clearance, which means US citizenship. Do you have any concerns about that process or your eligibility?

confirming a hard eligibility requirement before investing further in the candidate

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The full job description

As published by Boeing.

Experienced or Senior Mechanical System Design Engineers Company: The Boeing Company Boeing St. Louis is building the future ‒ creating innovative solutions that will define the next generation of aerospace.  We are currently seeking Experienced or Senior Mechanical System Design Engineers to develop, maintain and modify air vehicle subsystems (Armament, Crew Systems, Environmental Cooling, Equipment, Fuel, Hydraulics, Landing Gear, Mechanisms and Thermodynamic) and component designs, using 3-D Computer Aided Design tools and/or other design methods, to provide product definition to other engineering groups, production operations, suppliers and external customers throughout the product lifecycle. These positions are located in the St. Louis region and support current and emerging aircraft programs as part of the Air Dominance division in Boeing Defense Space and Security (BDS). Positions will be located at one of the listed locations: Berkeley, MO; Hazelwood, MO; St. Louis, MO; St. Charles, MO; Mascoutah, IL. Position Responsibilities: Level 3 • Develop, integrate and document air vehicle subsystems requirements to establish the system design • Develop, maintain and modify air vehicle subsystems and component designs, using 3-D Computer Aided Design tools and/or other design methods, to provide product definition to other engineering groups, production operations, suppliers and external customers throughout the product lifecycle • Perform, integrate analytical and test results to validate and verify systems and components meet requirements and specifications • Manage supplier development, test and production activities and coordinates with the supplier to optimize the design and achieve program goals • Develop new design/analysis processes and tools to improve the effectiveness, quality and efficiency of the development effort • Investigate emerging technologies to develop concepts for future product designs to meet projected requirements • Work under general direction Level 4 • Develop, integrate and document air vehicle subsystems requirements to establish the system design • Develop, maintain and modify air vehicle subsystem and component designs, using 3-D Computer Aided Design tools and/or other design methods, to provide product definition to other engineering groups, production operations, suppliers and external customers throughout the product lifecycle • Lead performance, integration and analysis of tests to validate and verify systems and components meet requirements and specifications • Manage supplier development, test and production activities and coordinates with the supplier to optimize the design and achieve program goals • Assist with investigation of emerging technologies to develop concepts for future product designs to meet projected requirements • Work under minimal direction Basic Qualifications (Required Skills / Experience): • Bachelor of Science degree in Engineering (with a focus on Mechanical, Civil, Aerospace Aeronautical or Material Sciences) • Level 3: 5 or more years' related work experience or an equivalent combination of technical education and experience • Level 4: 9 or more years' related work experience or an equivalent combination of technical education and experience • Experience using NX / Teamcenter and familiarity with reading 2-D drawings • This position requires the ability to obtain a US Security Clearance for which the US Government requires US Citizenship as a condition of employment. An interim and/or final U.S. Secret Clearance Post-Start is required. • Some positions may require the ability to obtain Special Program Access, for which the U.S. Government requires U.S. Citizenship only. Preferred Qualifications (Desired Skills / Experience): • Mechanical Design experience on military or commercial aircraft • An active U.S. Security Clearance in the past 24 months • Experience leading and working with aircraft fluid systems design and components including pumps, valves, heat exchangers, sensors and controls • Experience with component requirement specifications and managing supplier development activities • Experience with thermal analysis tools such as ANSYS Thermal Desktop • Experience with modeling and simulation software such as Matlab, Simulink, Simcenter Amesim and Flomaster • Experience with Model Based Systems Engineering concepts and tools such as Magic Systems of Systems Architect • The ability to work in a multidisciplinary team • Experience in developing solutions to a wide range of complex technical problems, requiring ingenuity and innovation Successful candidates for this job must satisfy the Company's Conflict of Interest (COI) assessment process. Drug Free Workplace: Boeing is a Drug Free Workplace where post offer applicants and employees are subject to testing for marijuana, cocaine, opioids, amphetamines, PCP, and alcohol when criteria is met as outlined in our policies. At Boeing, we strive to deliver a Total Rewards package that will attract, engage and retain the top talent.  Elements of the Total Rewards package include competitive base pay and variable compensation opportunities.  The Boeing Company also provides eligible employees with an opportunity to enroll in a variety of benefit programs, generally including health insurance, flexible spending accounts, health savings accounts, retirement savings plans, life and disability insurance programs, and a number of programs that provide for both paid and unpaid time away from work.  The specific programs and options available to any given employee may vary depending on eligibility factors such as geographic location, date of hire, and the applicability of collective bargaining agreements. The Boeing 401(k) helps you save for your future, with contributions from Boeing that can help you grow your retirement savings. Our best-in-class retirement benefit features: • Best in class 401(k) plan: we'll match your contributions dollar for dollar, up to 10% of eligible pay with Immediate 100% vesting • Student Loan Match: The Boeing 401(k) Student Loan Match allows eligible enrolled U.S. employees to have their qualified student loan debt payments counted, along with any match-eligible contributions they make, for purposes of determining the Company Match to employees' Boeing 401(k) accounts.  Pay is based upon candidate experience and qualifications, as well as market and business considerations.  Summary Pay Range: Level 3: $103,700 - $140,300 Level 4: $126,650 - $171,350 Language Requirements: Not Applicable Education: Bachelor's Degree or Equivalent Relocation: This position offers relocation based on candidate eligibility. Export Control Requirement: Safety Sensitive: Security Clearance: This position requires the ability to obtain a U.S. Security Clearance for which the U.S. Government requires U.S. Citizenship. An interim and/or final U.S. Secret Clearance Post-Start is required. This position requires ability to obtain program access, for which the U.S. Government requires U.S. Citizenship only. Visa Sponsorship: Employer will not sponsor applicants for employment visa status. Contingent Upon Award Program This position is not contingent upon program award Shift: Shift 1 (United States of America) Stay safe from recruitment fraud! The only way to apply for a position at Boeing is via our Careers website. Learn how to protect yourself from recruitment fraud - Recruitment Fraud Warning Boeing is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, national origin, gender, sexual orientation, gender identity, age, physical or mental disability, genetic factors, military/veteran status or other characteristics protected by law. EEO is the law Boeing EEO Policy Request an Accommodation Applicant Privacy Boeing Participates in E – Verify • E-Verify (English) • E-Verify (Spanish) Right to Work Statement • Right to Work (English) • Right to Work (Spanish)

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