Lead Mechanical Engineer - TS/SCI Polygraph Required

Leidos is seeking an experienced Mechanical Engineer to support critical national security missions in Reston, Virginia. This role focuses on the assessment, reverse engineering, and characterization of complex above-ground and subterranean facilities located in denied-access environments.

The successful candidate will apply engineering expertise to analyze facility designs, spatial layouts, operational workflows, and supporting infrastructure to determine functional capabilities and mission relevance. You will evaluate facility systems, model critical infrastructure, identify vulnerabilities, and provide technical insights that support complex intelligence and defense initiatives.

This position requires a creative and analytical engineer who can develop sound technical assessments in situations where complete information is inherently unavailable. The ideal candidate combines strong problem-solving skills with engineering rigor, attention to detail, and a commitment to thorough analysis. You will work alongside an interdisciplinary team of government and contractor professionals in a fast-paced, mission-focused environment supporting high-priority national security objectives.

Primary Responsibilities

• Reverse Engineering: Dissect and characterize physical and functional attributes of facility layouts, building architecture, and workflows in denied access environments.

• Vulnerability Assessments: Evaluate facility and infrastructure designs for security vulnerabilities, single points of failure, and operational bottlenecks.

• 3D Modeling & Simulation: Build high-fidelity 3D models and conduct simulations to replicate facility workflows, operational efficiency, and structural/mechanical limitations.

• Infrastructure Analysis: Apply a strong, multidisciplinary engineering background to assess supporting facility systems, with a primary focus on Mechanical, Electrical, and Plumbing (MEP) integration.

• Technical Documentation: Translate field data and intelligence into comprehensive engineering reports, CAD/BIM drawings, and simulation results for DoD stakeholders.

• Perform customer approved R&D projects individually or as part of a team

• Serves as a subject matter expert within technical domain area.

Required Qualifications

• Candidates for consideration must possess an in-scope and active TS/SCI Polygraph clearance and the ability/willingness to maintain this clearance while holding this position. U.S. Citizenship is required.

• ​Demonstrated understanding of advanced engineering principles, theories, and concepts, and the ability to apply them across a broad range of technical programs and mission challenges.

• Bachelor's degree with 8+ years of relevant experience, or a Master's degree with 6+ years of relevant experience. Additional experience may be considered in lieu of degree.

• Relevant experience includes facility analysis, infrastructure vulnerability assessments, and mechanical engineering within commercial, Department of Defense, or Intelligence Community environments.

• MEP Systems Expertise: Strong multidisciplinary understanding of Mechanical, Electrical, and Plumbing (MEP) system design, integration, and operational functionality within complex industrial or military facilities, including specialized containment systems, filtration systems, and backup power infrastructure.

• Ability to identify industrial HVAC equipment, estimate system size and capacity, and assess operational capabilities through visual analysis.

• Ability to evaluate, organize, and utilize large datasets from diverse sources, including field-collected data, equipment technical manuals, and existing facility models.

• Expertise in 3D modeling, engineering analysis, and physical simulation methodologies.

• Experience interpreting engineering drawings, facility layouts, blueprints, and intelligence-derived technical data.

• Demonstrated ability to make sound technical judgments with incomplete information while clearly communicating assumptions, uncertainties, and recommended paths forward.

Preferred Qualifications

• Five or more years of field experience working with industrial HVAC systems, including air-cooled and water-cooled chillers, condensers, cooling towers, air handlers, heat exchangers, boilers, and related equipment.

• Working knowledge of air management systems supporting critical environments, including medical laboratories, clean rooms, chemical laboratories, and similar specialized facilities.

• Hands-on experience with advanced Building Information Modeling (BIM) and engineering simulation tools, including Autodesk Revit, VENTSIM, ETAP, and other industry-standard CAD and modeling platforms.

• Experience supporting forensic engineering investigations, industrial accident analyses, or Department of Defense facility vulnerability studies.

• Professional Engineer (PE) license and/or Project Management Professional (PMP) certification.

• Experience identifying mechanical system vulnerabilities and developing effective mitigation or corrective action strategies.

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If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

August 14, 2026

Pay Range:

Pay Range $107,900.00 - $195,050.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.