Human Systems Integration - Engineer JT4 LLCHuman Systems Integration - EngineerEdwards AFB, California$110,000–$185,000 / yearSome jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment. Candidates will perform a variety of engineering tasks in the field of aerospace human systems integration (HSI) in design, development, manufacturing, testing, installation, integration, sustainment, operations, and maintenance of electronic, and/or mechanical equipment and systems.
NewSystem Integration Engineer - Remote Teoresi GroupSystem Integration Engineer - RemoteSan Jose, CARemoteAt Teoresi, we specialize in supporting companies in creating projects using cutting-edge technologies such as self-driving cars and nanotechnology for the medical field. Teoresi Inc is an international Group, with offices in Europe and United States, that acts as an engineering partner to customers’ product and process development.
Sr. Electrical Engineer, Bee Amazon.com Services LLCSr. Electrical Engineer, BeeSan Francisco, CAYou'll work closely with a small, tight-knit team including mechanical engineers and industrial designers to ensure electrical systems integrate seamlessly into elegant product designs. You'll work directly with the Head of Hardware, and have close collaboration with mechanical engineers, firmware developers, and product designers who are all equally invested in creating exceptional products.
Electrical Design Engineer Tigo EnergyElectrical Design EngineerLos Gatos, CA$85,000–$95,000 / yearFull timeThe Electrical Desing Enginner will use scientific methodologies and circuit design techniques to develop manufacturable products from a comprehensive integrated systems perspective.
Power Engineer Tigo EnergyPower EngineerLos Gatos, CA$155,000–$170,000 / yearFull timeThe ideal candidate combines deep technical understanding with strong business leadership and market insight to drive scalable, intelligent energy management solutions that integrate hardware and software into seamless customer experiences. This role will own the software experience across IoT-connected devices, cloud platforms, mobile applications, analytics, and AI-driven technologies supporting residential, commercial & industrial (C&I), and utility-scale renewable energy systems.
Senior Systems Engineer V JT4Senior Systems Engineer VEdwards AFB, CA$150,000–$175,000 / yearFull timeJT4 is seeking a Senior Systems Enginee r V at its location on Edwards Air Force Base in California. Must be a US citizen.
Lead Dimensional Engineer-Autonomous Vehicle Sensors (Multi-Platform) ComriseLead Dimensional Engineer-Autonomous Vehicle Sensors (Multi-Platform)Foster City, CA$0–$105 / hourFull timeDatum and Tolerance Strategy: Define vehicle build requirements, establish robust datum schemes, sensor mounting locator strategies, and tolerance allocations to guarantee rock-solid sensor-to-body and sensor-to-sensor co-calibration stability. Supplier Capability and PPAP: Partner directly with Supplier Quality (SQ) teams to evaluate supplier capability, establish dimensional acceptance criteria, and resolve engineering escalations to protect program milestones.
Senior Hardware Development Engineer, AWS Mainstream Compute Amazon Web Services, Inc.Senior Hardware Development Engineer, AWS Mainstream ComputeCupertino, CAYou will work closely with our customers to understand their technical needs and business goals, leveraging your experience with server design and the knowledge of various teams to architect the solutions that we will deploy at scale. We pioneered cloud computing and never stopped innovating — that’s why customers from the most successful startups to Global 500 companies trust our robust suite of products and services to power their businesses.
NewAirborne Electronic Attack (AEW) Systems Integration Enigineer DCS CorporationAirborne Electronic Attack (AEW) Systems Integration EnigineerRidgecrest, CA$96,757–$114,000 / yearAirborne Electronic Warfare (AEW) Systems Integration Engineer supporting the F/A-18 & EA-18G Integrated Product Team (IPT) the incumbent will be required to support requirements analysis, acquisition, test, and Fleet support for AEA and/or EW sub-systems integration efforts as required. Program Office, Technical Program Office (TPO), NAVAIR, Boeing, NGC, etc.) on matters related to Weapons integration, project planning, scheduling, document preparation, engineering assessments and integration planning.
Senior Software Engineer, Data Integrations (Java/Python) BlackRockSenior Software Engineer, Data Integrations (Java/Python)San Francisco, CAIn this role, you will work across APIs, data pipelines, microservices, and relational data stores, partnering closely with product, analytics, and business stakeholders to ensure data and services are reliable, secure, and delivered at scale. At BlackRock SMA Solutions, our strategies are designed to put our clients’ and their clients’ interests at the center of our investment advice; to minimize costs and taxes; and to incorporate each client’s unique values-aligned preferences into their investment portfolio.
Sr. Software Systems Engineer - China Lake JT4 LLCSr. Software Systems Engineer - China LakeRidgecrest, California$131,601.60–$158,601.60 / yearJT4, LLC is looking for a highly experienced Senior Software Systems Engineer that is highly proficient with object oriented software design and that is also well versed with live-virtual-constructive simulation and aircraft avionics to MIL-STD-1153 and MIL-STD-1773. Some jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license or other licenses / certifications and the inability to obtain and maintain the required clearance, license or certification may affect an employee's ability to maintain employment.
Software Systems Engineer - China Lake JT4 LLCSoftware Systems Engineer - China LakeRidgecrest, California$127,358–$142,358 / yearJT4, LLC is looking for a Software Systems Engineer that is highly proficient with object oriented software design and that is also well versed with live-virtual-constructive simulation and aircraft avionics to MIL-STD-1153 and MIL-STD-1773. Some jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license or other licenses / certifications and the inability to obtain and maintain the required clearance, license or certification may affect an employee's ability to maintain employment.
Team Hornet Systems Engineer DCS CorporationTeam Hornet Systems EngineerRidgecrest, CA$70,310–$90,500 / yearParticipate in peer review for various requirements documentation (Functional Requirement Sheets/Documents, Interface Control Documents, Statement of Limitations, System and Subsystem Requirements, etc.). The individual must have strong communication skills that are necessary to effectively coordinate integration and certification activities across multiple engineering disciplines and support organizations.
DTP-N System Engineer DCS CorporationDTP-N System EngineerRidgecrest, CA$96,757–$120,000 / yearAs Distributed Targeting Processor -Networked (DTP-N) Systems Engineer supporting the F/A-18 and EA-18G Integrated Product Team (IPT) the incumbent will be required to support requirements analysis, acquisition, test, and Fleet support for DTP-N and other CNI / AVMS efforts as required. Program Office, Technical Program Office (TPO), NAVAIR, Boeing, NGC, etc.) on matters related to Weapons integration, project planning, scheduling, document preparation, engineering assessments and integration planning.
JSSA Systems Engineer DCS CorporationJSSA Systems EngineerRidgecrest, CA$70,310–$75,000 / yearConduct requirements development, contribute to design reviews, develop and execute system evaluation test procedures for laboratory and flight integration events, characterize and document anomaly reports, troubleshoot and verify system and sub-system anomalies, perform system data analysis using MUX 1553 raw data and video data, log and document integration activities throughout the aircraft life cycle block upgrades. Support airborne systems installation, maintenance, and troubleshooting to support integration efforts, respond to inquiries from the fleet operators, and support fleet introductions of new and modified systems.
NewSystems Engineer III #26-17842 US Tech Solutions, Inc.Systems Engineer III #26-17842Valencia, CAKey Responsibilities Leads or participates on project teams to develop clear specifications, evaluates feasibility of concepts, and provides formal estimates for electrical/software designs. Independently or as a member of a team directs, develops, concepts, and executes specifications, designs, plans and builds of complex manufacturing and test equipment.
Sr. Physical Design Engineer - Static Timing Analysis, Annapurna Labs, Cloud Scale Machine Learning Annapurna Labs (U.S.) Inc.Sr. Physical Design Engineer - Static Timing Analysis, Annapurna Labs, Cloud Scale Machine LearningCupertino, CAAs a member of the Cloud-Scale Machine Learning Acceleration team you’ll be responsible for the design and optimization of Hardware in our data centers including technologies such as AWS Inferentia which is a machine learning inference product designed to deliver high performance at low cost. As a member of the UC organization, you’ll support the development and management of Compute, Database, Storage, Internet of Things (IoT), Platform, and Productivity Apps services in AWS, including support for customers who require specialized security solutions for their cloud services.
Test Engineer II (Torrance, CA) - 2 positions GCR Professional ServicesTest Engineer II (Torrance, CA) - 2 positionsTorrance, California$36–$46 / hourContractorTest Planning and Strategy: Collaborate with cross-functional teams, including design engineers and project managers, to understand the requirements and specifications of defense and aerospace systems. Test Automation and Continuous Improvement: Identify opportunities for test automation and develop automated test scripts and frameworks to streamline testing processes and increase efficiency.
Senior Ride Control Hardware Engineer (Controls Automation) Walt Disney ImagineeringSenior Ride Control Hardware Engineer (Controls Automation)Glendale, CA$129,300–$173,300 / yearWorking across a spectrum of disciplines that range from creative and conceptual to scientific and technical, Imagineers blend an innovative mixture of storytelling, art, science, and technology to create immersive experiences, memorable destinations, and innovative entertainment for families around the globe. About The Role & Team Walt Disney Imagineering is the creative force that imagines, designs, and brings to life all Disney theme parks, resorts, attractions, and cruise ships worldwide.
NewElectrical Engineer II (Torrance, CA) - HYBRID GCR Professional ServicesElectrical Engineer II (Torrance, CA) - HYBRIDTorrance, CaliforniaContractorSystem Analysis: Analyze electrical systems and circuits, perform calculations, and use simulation software to evaluate their performance and make necessary improvements. *Collaboration: Collaborate with other engineers, technicians, and professionals to integrate electrical systems into larger projects or products.
Sr. Test Engineer – AN2024 Marvin Test SolutionsSr. Test Engineer – AN2024Irvine, CAAbility to technically lead a team of cross functional engineers and providing leadership, mentorship and guidance to complete technical and design tasks to achieve project goals. Responsibilities: You will work in an exciting and fast-paced environment designing and integrating test systems and Test Program Sets (TPS) for commercial and military electronics.
Senior Robotics Automation Engineer Daiichi Sankyo, Inc.Senior Robotics Automation EngineerSan Diego, CA$136,080–$204,120 / yearFull timeEvaluate, integrate, configure, troubleshoot, and maintain advanced laboratory automation systems, including liquid handlers, dispensers, pipettors, plate movers, robotic arms, plate sealers and desealers, acoustic transfer devices, multimodal assay readers, incubators, storage systems, and related scientific instrumentation. This role requires deep expertise in laboratory automation, engineering principles, scientific workflows, and biopharma research operations, combined with the ability to influence technical direction, guide cross-functional decision-making, and mentor less experienced engineers and scientists.
C4ISR - Engineer JT4 LLCC4ISR - EngineerEdwards AFB, California$110,000–$185,000 / yearThe candidate must have a Bachelor of Science in Engineering from an ABET-accredited academic institution and four years of related engineering experience or have an accredited Master of Science in Engineering with at least 2 years of related engineering experience or have an accredited doctoral degree in Engineering. Some jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment.
NewAEW flight Test Engineer DCS CorporationAEW flight Test EngineerRidgecrest, CA$84,137–$90,000 / yearAirborne Electronic Warfare (AEW) Flight Test Engineer supporting the F/A-18 & EA-18G Integrated Product Team (IPT) the incumbent will be required to support Flight Test and Fleet support for AEA and/or EW sub-systems integration efforts as required. Report systems performance in official Navy Test and Evaluation reports, such as Daily Test Summaries, Naval Message Report, DT/OT Transition report, Summary Report, RTR, Deficiency Report.
Software Engineer - GUI/OpenGL DCS CorporationSoftware Engineer - GUI/OpenGLPoint Mugu, CA$84,137–$125,000 / yearThe engineer will collaborate with cross-functional teams, including hardware, systems, and test engineers, to deliver high-performance, mission-focused software solutions for Department of Defense (DoD) programs. The Software Engineer will design, develop, integrate, and test advanced software applications with a primary focus on Graphical User Interface (GUI) development using OpenGL and Microsoft Visual Studio.
Embedded Software Computer Engineer DCS CorporationEmbedded Software Computer EngineerRidgecrest, CA$82,004–$107,593 / yearCommunication skills required, both verbally and in writing, to interface with an Integrated Product team that includes Systems and Software Engineers as well as technical leadership in both government and contractor roles. Perform software engineering duties over the product life cycle environment, encompassing requirements development, requirements analysis, design, coding, unit testing, system integration, and problem investigation.
Systems Engineer LeidosSystems EngineerSpring Valley, CA$87,100–$157,450Support aspects of system engineering for SMIT, to include technical planning, design, development, integration, assessment, and requirements analysis, as well as future capability needs (near and long-term) to drive the design and maintain an IT Enterprise. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at LeidosCareersFraud@leidos.com.
System Engineer - ArcGIS EsriSystem Engineer - ArcGISRedlands, CA$120,640–$197,600 / yearDeploy and configure ArcGIS in a wide variety of environments across operation systems, cloud providers, security architectures, customer types and organizations, to meet the customers service level agreement. Experience with Esri software including ArcGIS Enterprise, ArcGIS Desktop, ArcGIS Online, Portal for ArcGIS and ArcGIS Runtime and their associates APIs or interfaces.
Sr. System Engineer - ArcGIS EsriSr. System Engineer - ArcGISRedlands, CA$156,000–$239,200 / yearDeploy and configure complex ArcGIS in a wide variety of environments across operation systems, cloud providers, security architectures, customer types and organizations, to meet the customers service level agreement. Experience with Esri software including ArcGIS Enterprise, ArcGIS Desktop, ArcGIS Online, Portal for ArcGIS and ArcGIS Runtime and their associates APIs or interfaces.
Video Engineer - China Lake CA JT4 LLCVideo Engineer - China Lake CARidgecrest, California$96,491.20–$111,491.20 / yearThe engineer will work in collaboration with the branch's technical and engineering teams and provide technically sound advice to managers and peers on the technical aspects of system development, and may require managing small to medium-sized projects. Some jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment.
Systems Engineer DCS CorporationSystems EngineerPoint Mugu, CA$73,160–$85,000 / yearCoordinate analysis activities and products with functional team leaders, senior management, and other personnel responsible for executing analysis tasks. In this role, you will be at the forefront of innovation, contributing to the development of sophisticated hardware and software solutions for complex challenges in the electronic warfare domain.
NewEngineer IV - JSE Edwards JT4 LLCEngineer IV - JSE EdwardsEdwards AFB, California$135,000–$170,000 / yearA Bachelor of Science in Engineering from an ABET-accredited academic institution and eight (8) years of related engineering experience, or an accredited Master of Science in Engineering and a minimum of six (6) years of related engineering experience, or an accredited doctorate degree in engineering and a minimum four (4) years of related engineering experience are required for this position. Some jobs may require a candidate to be eligible for a government security clearance, state-issued driver’s license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee’s ability to maintain employment.
NewSenior Blockchain Engineer, Digital Assets Charles SchwabSenior Blockchain Engineer, Digital AssetsSan Francisco, CAThis is a hands on engineering role focused on Layer 1 blockchain integration, core blockchain infrastructure components, wallet engineering, and custody related blockchain workflows. The role works in close partnership with Crypto Custody Lead Engineers and Crypto Security Engineers to ensure blockchain interactions are secure, reliable, observable, and production ready.
Radar Fusion - Engineer JT4 LLCRadar Fusion - EngineerEdwards AFB, California$110,000–$185,000 / yearSome jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment. The candidate must have a Bachelor of Science in Engineering from an ABET-accredited academic institution and four years of related engineering experience or have an accredited Master of Science in Engineering with at least 2 years of related engineering experience or have an accredited doctoral degree in Engineering.
Autonomy - Engineer JT4 LLCAutonomy - EngineerEdwards AFB, California$110,000–$185,000 / yearDevelop test plans and procedures for the integration, characterization, and testing of complex test Navigation, Defense Aviation Systems, Intelligence, Surveillance, and Reconnaissance platforms, Command & Control, Automation, Flight Controls, Guidance Navigation & Control, and Inertial Navigation Systems, Global Navigation Satellite System Integration, and Navigation Error Modeling. The candidate must have a Bachelor of Science in Engineering from an ABET-accredited academic institution and four years of related engineering experience or have an accredited Master of Science in Engineering with at least 2 years of related engineering experience or have an accredited doctoral degree in engineering.
JSSA Software Engineer DCS CorporationJSSA Software EngineerRidgecrest, CA$73,160–$95,500 / yearKnowledge in avionics computer systems (embedded software development), Team Software Process (TSP), Configuration Management (CM), Capability Maturity Model (CMM/CMMI) are a plus. Provide software engineering/programming services to the T-45 JSSA Integrated Product Team (IPT) program at NAWCWD China Lake.
NewSenior Mobile iOS Full-Stack Engineer Pinnacle Technical ResourcesSenior Mobile iOS Full-Stack EngineerCupertino, CaliforniaContractorThis role requires someone who is comfortable owning features end-to-end—from designing intuitive mobile experiences to integrating with backend services and cloud infrastructure. We are seeking an experienced Senior Mobile iOS Full-Stack Engineer to join a high-performing engineering team developing large-scale, customer-facing mobile applications.
Field Engineer III JT4 LLCField Engineer IIIEdwards AFB, California$97,000–$135,000 / yearThe systems to be supported are comprise of, but are not limited to, power generation equipment, power distribution units, uninterruptible power supply (UPS), backup generators, multifueled, and portable power generators, dedicated mission heating, ventilation, and air conditioning (HVAC), aircraft power systems (270 VDC, 28 VDC). A Field Engineer III performs as a lead on more complex field engineering assignments and performs a variety of engineering assignments involving technology applications involved in the installation, operation, testing, and maintenance of complex electronic/mechanical equipment and systems.
NewPrincipal Hardware Engineer, AI Systems MicrosoftPrincipal Hardware Engineer, AI SystemsMountain View, CA$142,800–$274,800 / yearMasters Degree in Electrical Engineering, Computer Engineering, Mechanical Engineering, or related field AND 7+ years technical engineering experience OR Bachelors Degree in Electrical Engineering, Computer Engineering, Mechanical Engineering, or related field AND 8+ years technical engineering experience. To achieve this goal, the Cloud Hardware Systems Engineering (CHSE) team is instrumental in defining and delivering operational measures of success for hardware manufacturing, improving the planning process, quality, delivery, scale and sustainability related to Microsoft cloud hardware.
Engineer III - Structures JT4 LLCEngineer III - StructuresEdwards AFB, California$110,000–$135,000 / yearSome jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment. JT4 develops and maintains realistic, integrated test and training environments and prepares our nation's war-fighting aircraft, weapons systems, and aircrews for today's missions and tomorrow's global challenges.
Structures - Engineer JT4 LLCStructures - EngineerEdwards AFB, California$110,000–$185,000 / yearSome jobs may require a candidate to be eligible for a government security clearance, state-issued driver's license, or other licenses/certifications, and the inability to obtain and maintain the required clearance, license, or certification may affect an employee's ability to maintain employment. JT4 develops and maintains realistic, integrated test and training environments and prepares our nation's war-fighting aircraft, weapons systems, and aircrews for today's missions and tomorrow's global challenges.
Propulsions - Engineer JT4 LLCPropulsions - EngineerEdwards AFB, California$110,000–$185,000 / yearResponsibilities will include providing technical input to test planning efforts, developing and/or modifying data analysis tools, defining engine test instrumentation requirements, supporting test execution, including control room support, performing post-flight data analysis, and assisting with technical reporting. Support the Director of Propulsion Safety and Technical Review (DoPSTR), Joint Propulsion Council meetings and special topic IPTs, assist in the coordination of input from allied engineering disciplines (avionics, armament, electronic warfare, flying qualities, performance, structures, subsystems, and signature) for PI T&E.
NewSr. Software Engineer Infotron SolutionsSr. Software EngineerSanta Clarita, CA$184,558 / yearFull timeAnalyze/document data flows across multiple enterprise systems/trading/accounting, compliance/risk platforms for accurate data integration/reporting. Requires BS in computer science/Computer Applications/closely related (foreign equivalent).
Specialty Software Engineer 3 - Contingent Pinnacle Technical ResourcesSpecialty Software Engineer 3 - ContingentConcord, California$60–$70 / hourContractorClient is engineering a next-generation Digital Asset Platform designed to solve the "Approval-to-Execution Gap" in institutional finance: ensuring that digital asset transactions are signed only when strictly authorized by policy, without exposing private keys to cloud operators or insiders. Confidential Computing Architecture: Design and build services that run inside Trusted Execution Environments (TEEs), specifically targeting AMD SEV-SNP and Intel TDX via Confidential Containers (CoCo).
Senior Software Engineer - Connected Workflows SamsaraSenior Software Engineer - Connected WorkflowsAnywhere, CARemoteConnected Workflows power critical work across safety, compliance, maintenance, operations, and field workflows, enabling drivers and frontline teams to collect structured data, trigger automations, and give back-office teams real-time visibility. The Connected Workflows team builds Samsara’s digital Connected Workflows platform, helping customers replace paper-based operational workflows with configurable, mobile-first Connected Workflows.
Remote Senior Flutter / Dart Mobile Engineer Kforce Inc.Remote Senior Flutter / Dart Mobile EngineerCarlsbad, CARemote$150,000–$175,000Employee pay is based on factors like relevant education, qualifications, certifications, experience, skills, seniority, location, performance, union contract and business needs. By clicking “Apply Today” you agree to receive calls, AI-generated calls, text messages or emails from Kforce and its affiliates, and service providers.
Software Development Engineer in Test II (SDET) – ArcGIS Enterprise EsriSoftware Development Engineer in Test II (SDET) – ArcGIS EnterpriseRedlands, CA$101,192–$167,336 / yearAs a SDET, you will work with our cross-functional global team of product engineers, software engineers, designers, product managers, and release engineers to understand functional and non-functional requirements and have them be recorded in your automated tests. Build the next generation of ArcGIS Enterprise, a suite of products delivering state-of-the-art mapping and analytics capability to thousands of customers and millions of users worldwide.
NewHardware-In-Loop Engineer Kforce Inc.Hardware-In-Loop EngineerPalo Alto, CA$65–$90Kforce's client, a leading automotive engineering organization in Palo Alto, CA is expanding its Hardware-in-the-Loop (HIL) validation capability and is actively seeking experienced HIL Engineers to support the buildout of multiple new systems. Preferred Experience Areas: Candidates may come from various domains, but strongest alignment includes: Low Voltage Systems (high priority).
NewSenior Firmware Engineer MicrosoftSenior Firmware EngineerMountain View, CA$119,800–$234,700 / yearDoctorate in Electrical Engineering, Computer Engineering, Computer Science, or related field AND 1+ year(s) technical engineering experience OR Masters Degree in Electrical Engineering, Computer Engineering, Computer Science, or related field AND 4+ years technical engineering experience OR Bachelors Degree in Electrical Engineering, Computer Engineering, Computer Science, or related field AND 5+ years technical engineering experience OR equivalent experience. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $160,200 - $261,000 per year.
Engineer V - JSE Edwards JT4 LLCEngineer V - JSE EdwardsEdwards AFB, California$150,000–$175,000 / yearA Bachelor of Science in Engineering from an ABET-accredited academic institution and 14 years of related engineering experience, or an accredited Master of Science in Engineering and a minimum of 10 years of related engineering experience, or an accredited doctorate degree in engineering and a minimum of eight (8) years of related engineering experience are required for this position. Ability to develop, execute, and report on classified test events focused on verification and validation of system requirement, integrated model capabilities, and data architectures to determine that the digital battlespace environment properly represents virtualized open air engagements.