Advanced diagnostics for air conditioning systems: Annecy Électronique’s know-how at the service of a major helicopter manufacturer

On-board air conditioning is vital to the safety, performance and comfort of crews and passengers. On demanding platforms such as helicopters, these systems must function optimally whatever the operating conditions. Guaranteeing their reliability requires diagnostic tools capable of accurately measuring physical quantities, analyzing their consistency and providing feedback that can be immediately exploited by maintenance teams.

In this context,a major helicopter manufacturer entrusted Annecy Électronique with the design and development of the ACS-DIAG tool, specially adapted to air conditioning loops running on R134a fluid.

A comprehensive, modular diagnostic tool

TheACS-DIAG combines a robust measurement case, a suite of specific sensors and a dedicated PC software application.

It offers users several complementary modes:

Measurement mode: real-time acquisition of pressure (0-40 bar HP, 0-12 bar BP), temperature (-20°C to +120°C via thermocouple probes) and humidity (0-100% RH), with graphic display and data logging.
Diagnostic mode: automated analysis of air-conditioning loop performance. The tool directly interprets the measured values and provides a final diagnosis (correct operation, identified fault, efficiency of cold air produced, fluid charge, probable causes of failure).
Control mode: targeted checks on key components – overall efficiency, refrigerant charge, condenser, evaporator, compressor – with graphical representation of results (Mollier diagrams, superheat or subcooling curves).
Electronic diagnostics mode: direct communication with an air-conditioning system control module, enabling visualization of input/output status, dynamic monitoring (cockpit or cabin) and decoding of fault messages.

Thanks to this integrated approach, technicians can move from a simple one-off measurement to an in-depth, documented analysis, reducing downtime and making maintenance operations more reliable.

Designed for operational use

The ACS-DIAG is designed for use in the field:

Modular architecture: 5 universal connectors capable of automatically recognizing connected sensor beams.
Rugged and reliable: IP40 ABS enclosure, wide operating temperature range (-20°C to +70°C).
User-friendly: carrying case with all harnesses (high and low pressure, TK1-4 thermocouples, THR temperature/hygrometry probe), wiring and intuitive software interfaces.
Interoperability: Windows-compatible PC application, with automatic report generation in PDF or CSV format for traceability and technical support.

The tool is also scalable: its software architecture enables updates and the addition of new functions, according to the needs expressed.

From aeronautics to other fields

The development of the ACS-DIAG illustratesAnnecy Electronique ‘s ability to design measurement and diagnostic solutions adapted to critical environments. Our design office masters :

electronic and software design,
integration of physical sensors and communication protocols,
the development of automated diagnostic algorithms,
industrialization and qualification of field equipment.

While this project was carried out for the aeronautics industry, our skills can be applied to other sectors: special vehicles, mobile machines, railways, automobiles, etc., wherever the performance of a thermal or air-conditioning system needs to be measured, analyzed and guaranteed.

Let’s build your diagnostic solution together

Each system has its own specific technical features and operating constraints. That’s why we offer to help our partners design tailor-made tools, combining robustness, precision and ease of use.