Sr. Principal Thermal Integration Engineer

About the Company

Blue Bird (NASDAQ: BLBD) is recognized as a technology leader and innovator of school buses since its founding in 1927. The company designs, engineers, and manufactures school buses with a focus on safety, reliability, and durability. School buses carry 25 million children twice a day, making them the most trusted mode of student transportation. Blue Bird is a leader in low- and zero-emission school buses, with over 25,000 propane, natural gas, and electric-powered buses sold. The company is transforming the student transportation industry through cleaner energy solutions.

About the Role

The Sr. Principal Thermal Integration Engineer is responsible for the vehicle-level thermal management strategy for next-generation commercial chassis platforms from concept through production launch. This role involves engine and transmission cooling, HVAC integration, cooling module design, airflow management, coolant routing, fan strategy, thermal controls, and heat rejection performance across demanding commercial vehicle duty cycles. The engineer will make vehicle-level technical decisions affecting chassis packaging, durability, serviceability, manufacturing, performance, and launch timing. This high-accountability role requires an experienced thermal specialist who can create solutions from a blank slate, make sound decisions with incomplete information, and own results from concept through production.

Responsibilities

• Define and own the commercial chassis cooling architecture, including engine cooling, transmission cooling, HVAC integration, coolant circuits, airflow management, fan strategy, and thermal protection.
• Design and optimize cooling modules, radiators, charge air coolers, condensers, heat exchangers, pumps, fans, valves, reservoirs, plumbing, and related components.
• Lead integration of thermal systems into the chassis while balancing heat rejection, packaging, manufacturability, serviceability, durability, cost, and production readiness.
• Develop cooling strategies for high ambient temperatures, low-speed operation, extended idle, grade performance, stop-and-go use, heavy payloads, and other severe commercial vehicle conditions.
• Perform and interpret 1D and 3D thermal-fluid analyses to optimize coolant flow, airflow, heat rejection, fan performance, and system efficiency.
• Define requirements and operating strategies for fans, pumps, valves, compressors, protection logic, and thermal derate functions in collaboration with controls engineering.
• Provide technical direction to suppliers and engineering service providers while retaining ownership of requirements, component selection, design decisions, performance, and technical deliverables.
• Develop and execute thermal DVP&R activities through laboratory, dynamometer, environmental, proving-ground, and vehicle testing to confirm readiness for production.
• Support prototype builds, pilot operations, production launch, and early manufacturing by resolving packaging, assembly, supplier, and performance issues with urgency.
• Lead investigation and resolution of overheating, insufficient heat rejection, coolant imbalance, leakage, airflow recirculation, HVAC deficiencies, thermal derating, and field reliability concerns.
• Operate in ambiguity, creating structure and driving execution where requirements, packaging constraints, supplier capabilities, and technical solutions are evolving simultaneously.

Requirements

• Bachelor’s degree in Mechanical, Aerospace, or Automotive Engineering or a related discipline with an emphasis in thermal sciences, heat transfer, or fluid mechanics.
• 10+ years of experience developing vehicle cooling systems, thermal architectures, HVAC systems, or heat rejection solutions for automotive, commercial vehicle, heavy-duty, off-highway, or similarly complex mobile platforms.
• Deep expertise in commercial vehicle cooling systems, thermodynamics, heat transfer, fluid dynamics, refrigeration cycles, and airflow management.
• Strong understanding of engine, transmission, HVAC, and auxiliary cooling systems for commercial or heavy-duty vehicle applications.
• Proven ability to make vehicle-level technical trade-offs involving performance, packaging, durability, serviceability, manufacturing, cost, and launch timing.
• Advanced experience with cooling module design, heat exchanger sizing, coolant routing, fan systems, thermal controls, and underhood airflow.
• Proficiency with GT-SUITE, Simcenter Amesim, ANSYS Fluent, Star-CCM+, or equivalent thermal and CFD tools.
• Experience developing requirements, DVP&R plans, DFMEAs, technical specifications, and system-level validation strategies.
• Experience instrumenting and testing vehicles using thermocouples, pressure transducers, flow meters, data acquisition systems, and CAN-based tools.
• Ability to direct suppliers and external engineering partners while maintaining technical ownership and accountability.
• U.S. citizenship or permanent residency is required.

Preferred Qualifications

• Demonstrated ownership of a major vehicle thermal system from concept through prototype development, validation, production launch, and issue resolution.
• Experience integrating thermal systems into constrained chassis packaging environments while balancing vehicle-level performance and production requirements.
• Experience making complex engineering decisions with limited structure, incomplete information, and aggressive program timing.
• Experience working directly with manufacturing, suppliers, external engineering partners, and cross-functional vehicle development teams.
• Experience with commercial trucks, buses, vocational vehicles, stripped chassis, body-on-chassis platforms, or incomplete vehicle applications.
• Experience developing cooling architectures for high-load, high-ambient, low-speed, grade, extended-idle, or severe-duty operation.
• Experience integrating multiple propulsion or vehicle configurations within a common commercial chassis architecture.
• Experience with clean-sheet or major redesign vehicle programs operating under aggressive launch timelines.
• Experience leading supplier technical development, component selection, industrialization, or recovery activities.
• Master’s degree in Mechanical Engineering, Aerospace Engineering, Automotive Engineering, or a related thermal discipline.
• Experience resolving thermal issues during prototype builds, manufacturing launch, or customer field operation.

Skills

• Strong analytical, troubleshooting, communication, and rapid decision-making skills.
• Ability to take ownership of complex vehicle behavior and controls challenges and drive them to resolution.
• Thrives in ambiguity and enjoys developing new control strategies from a clean sheet.
• Operates with urgency while maintaining strong engineering judgment.
• Thinks in systems and understands how software influences complete vehicle performance.
• Balances vehicle performance, energy efficiency, emissions, diagnostics, durability, and customer experience.
• Influences technical direction across cross-functional engineering teams, suppliers, and external engineering partners without direct authority.
• Desires meaningful ownership over how next-generation commercial vehicles perform in the real world.

Benefits

• Medical, dental, and vision insurance.
• 14 paid holidays.
• Vacation time.
• 401k matching.
• Continued professional development.

Work Conditions

• Office environment and production environment.
• Exposure to heat, cold, and noise in a manufacturing setting.
• Fast-paced production area with moving objects and sheet metal.
• Occasional periods of standing or sitting for extended periods of time.
• Must wear appropriate PPE when and where required.
• Frequent weeks working 40+ hours.
• Frequent communication with people throughout the day.