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Environmental control systems engineering: design, analysis, tests and certification
Design, analysis, tests and certification reports for aircraft environmental control systems (ATA 21): air conditioning, pressurization, avionics cooling and cabin comfort. We issue the certification documents; you review them and submit them to the authority.
From the cabin to the avionics bay: ECS modifications of a surveillance aircraft based on a business jet, ram air and heat exchanger CFD, cabin thermal comfort, and pressurization test proposals for the Embraer E2.
Environmental control systems track record
- Surveillance aircraft ECS modificationsRedesign of the Global 6000 ECS for a surveillance variant: ducting and routing as per 14 CFR Part 25.831, laboratory, ground and flight tests, and cabin comfort.
- ECS and ice protection STCA four-year program: design, tests and certification for icing and ECS, on a surveillance aircraft based on the Bombardier Global 6000.
- Ram air and heat exchanger CFDPressure drop and flow maldistribution in ducts, heat exchangers and fans.
- Cabin thermal comfort3D CFD to choose the best air intake distribution for passenger comfort.
- Electric aircraft cabinAMESim thermal model of cabin, e-bays and batteries over typical missions and climates.
- Embraer E2, 2014 to 2018Pressurization test proposals on the ground and in flight, within the pneumatic system package.
Complete packages, from requirements to certification reports
We prefer whole, long-term programs to isolated tasks: ATS responsible for design support, tests and the certification documents.
What a package covers
System and cabin analyses, component sizing, test proposals, test support and the compliance reports. We issue these documents ourselves, from analysis or test results. You review them and submit them to the authorities.
One team for the whole program
At least one associate senior engineer stays assigned from the first requirement to the last report, so decisions, test points and evidence stay consistent.
Modifications and new designs
Redesign of an existing ECS, with ducting and routing as per 14 CFR 25.831, or support to a new design, including electric aircraft where the thermal management of cabin and batteries matters.
Need only a part? We define the scope with you.
What you receive
Air conditioning cycle analysis
Air cycle and vapor cycle machines: performance and operating limits.
Pressure drop and flow distribution
Ducts, gasper valves, heat exchangers and ram air paths, with CFD where the flow is not one-dimensional.
Cabin thermal comfort
3D CFD of temperature and air velocity, air intake distribution, pulldown and pullup times.
Avionics and equipment cooling
Cooling designed for the temperature limits of each equipment, since 10 °C more roughly halves electronics life.
Pressurization and cabin altitude
Pressure schedules and cabin altitude limits, with the relevant requirements checked.
Certification documents
Test proposals, test results and compliance reports, and component qualification as per RTCA DO-160.
How an ECS is organized and certified
The ECS, ATA 21
The environmental control system is chapter ATA 21, divided into subchapters from 21-00 to 21-70. It conditions, distributes and pressurizes the air of the cabin and cools the avionics and other equipment.
Air is conditioned by air cycle or vapor cycle machines. The choice depends on the aircraft, the heat loads and the available power.
Analyses
Typical analyses are pressure drop, gasper valve flow, thermal comfort, and the pulldown and pullup of the cabin. According to Airbus, 90% of passengers care about comfort. Humidity and its control also matter for comfort and for the equipment.
3D CFD of the cabin shows how the air reaches each passenger, and how contaminants and viruses are carried by the flow. The result depends on the air flow pattern, which is why the intake distribution is studied.
Cabin altitude and pressurization
Cabin altitude is limited by regulation. The reference values are 6,000, 8,000 and 10,000 ft for different conditions, and the pressurization system and its control are verified against them.
Certification and tests
Equipment is qualified as per RTCA DO-160, including temperature chambers. System tests include ground tests and flight tests in extreme temperature conditions.
Tools, and where each one fits
Tools serve the engineering work. We say what each one does in the project.
| Tool | Role in the project | Status |
|---|---|---|
| CFD++ | Cabin comfort, ram air ducts, heat exchangers, fans and thermal analyses. | Licensed |
| AMESim, FloMaster | System models: cabin, e-bays and batteries, pneumatic supply and flow. Run with the client’s license. | Client license |
| Femap, NX Nastran, Adina | Structural analysis of ducts, supports and equipment. | Licensed |
| MATLAB | Control and dynamics. Run with the client’s license. | Client license |
| Python, Nsp, Scilab | Tools that need no license and replace MATLAB when the client does not provide one. | In use |
| Excel/VBA | 0D models and test data reduction. | Licensed |
Evidence you can check
Project work for aircraft manufacturers and integrators.
Project work
| Project | What we did | Tools and tests | Result or venue |
|---|---|---|---|
| Akaer and TA: surveillance aircraft, ECS modificationsProject | Redesign of the Global 6000 ECS for the surveillance variant, with a supplementary liquid cooling system for radar and equipment, ducting and routing as per 14 CFR Part 25.831, and cabin comfort for the occupants. | Laboratory, ground and flight tests. | Reports ready for submission. |
| Akaer and TA: ECS and ice protection STCProject | A four-year program: design, tests and certification for icing and ECS, on a surveillance aircraft based on the Bombardier Global 6000. | Design, simulation, tests and certification documents. | Certification reports ready for submission. |
| Enviro Systems: ram air, heat exchanger and fan CFDProject | Ram air circuit pressure drop and flow maldistribution. | 3D CFD. | Pressure recovery calculated for several flight conditions. Influence of the engine inlet on the wing flow assessed. |
| UNIP: cabin thermal comfort, CFDProject | Air intake distribution for passenger comfort, including an empty seat next to a passenger. | 3D CFD of temperature and velocity. | Temperature and speed mapping. Best air intake distribution selected for thermal comfort. |
| Archer: electric aircraft, cabin thermal modelProject | Cabin, e-bays and batteries over typical missions, in the climates of the target cities. Variable cooling system versus simple ventilation. Comfort for pilots and passengers. | AMESim thermal model. | Model supports ECS and component sizing and architecture decisions. |
| Mectron: radio cooling with heat pipesProject | Cooling of a high-power radio with ventilation and heat pipes. | Analytical and CFD models, validated, including radiation. | Design approved. Maximum operating temperature of the main chip calculated. |
| Embraer E2: pressurization test proposalsProject | Ground and flight test proposals for the pressurization system. | Within the Embraer E2 pneumatic system package. | Proposals developed by ATS. |
Examples
Select an image to see each example.
Ram air system
Ram air system with 3D CFD: pressure drop and flow maldistribution in ducts, heat exchanger and fan.
Request a technical proposalHow an engagement runs
Requirements and architecture
Certification basis, heat loads and the architecture of the ECS.
System model
Steady-state and transient models of the cycle, cabin and equipment bays.
Detailed analysis
CFD of the cabin, ducts, ram air and heat exchangers.
Tests and qualification
Test proposals, laboratory, ground and flight tests, and component qualification.
Compliance with requirements
Reports issued by ATS, reviewed and submitted by you.
Start of operation
Operation support, service difficulties and follow-up.
Related services
Questions engineers ask before they hire us
Which ECS subsystems do you cover?
All of ATA 21: air conditioning, pressurization, avionics and equipment cooling, ventilation, and the analyses of pressure drop, thermal comfort and cabin altitude. We can take the whole system or only the part you need.
Do you issue certification documents?
Yes. Test proposals, test results and compliance reports, including component qualification as per RTCA DO-160. You review them and submit them to the authority.
Can you modify an existing aircraft ECS?
Yes. We worked on the ECS modifications of a surveillance aircraft based on a business jet, redesigning ducting and routing as per 14 CFR 25.831, with laboratory, ground and flight tests, and on a combined ECS and ice protection STC program.
Do you analyze thermal comfort and the spread of contaminants?
Yes, with 3D CFD of the cabin: air intake distribution, passenger comfort, and the dispersion of contaminants and viruses, which depends on the air flow pattern in the cabin.
Do we need to provide a license for the tools?
For AMESim and FloMaster, yes: the client gives access to its license. MATLAB works the same way; Python, Nsp and Scilab need no license. CFD++, Femap, NX Nastran, Adina and Excel/VBA are licensed by ATS.
Is our data kept confidential?
Yes. We work under NDA, and your design data and reports stay with you.
Tell us about the aircraft and the certification stage
Send the aircraft, the system and the question you need answered.
aerospace@aerothermalsolutions.co+55 11 3854-4224An ATS engineer replies. We work under NDA.