Power requirements in your average helicopter represent a few uncommon challenges. Consider the startup power required to get those turbines spinning.  Then the instantaneous braking force necessary to respond to the pilots commands in real-time as he dips and rises to navigate safely.

All of that requires a pretty powerful engine, and that engine is lubricated by a whole lot of oil. Over a long trip or in hot/dusty conditions, that oil gets hot, too hot to be a very effective lubricant or coolant for the engine. If it remains too hot for too long, even specialized lubricants can break down and so oil temperature control has become a key safety subsystem in many high power, high rpm engines and motors on many kinds of military and industrial vehicles, boats and planes.

CPI Thermals are Helping the Next Generation of Helicopters Fly

The road to a world filled non-polluting electric vehicles doesn’t stop with cars. Manufacturers like Kopter helicopters of Switzerland already have their eyes on the prize. Per CEO Gian Piero Cutillo, of Leonardo who recently acquired Kopter, “… (Kopter) will act as a competence center for new light helicopters, developing future advanced technologies, especially in the areas of hybrid/electrical propulsion”.

Key to the success of this future roadmap is their new AW09 light helicopter. This is the first all new single engine helicopter design in over 4 decades, reimagined to be a design that could someday represents the world’s first hybrid chopper.

The powerful Honeywell HTS 900 turbine engine with 1020 hp is of particular interest to operators who wish to avail themselves of hot and high altitude performance.  But a critical single engine design requires a critical, fail-safe cooling system.

“For Kopter we actually created a custom version of our AD series SnapStat Thermal Switch with a MIL STD connector”, notes John Crozier of CPI. “The thermal switch is installed in an oil cooler heat exchanger for the helicopter”.  As is common to many CPI thermal switches used in this application, the switch activates when the oil temperature is above the thermal activation temperature (pre-programmed set point). The signal is used to switch a cooling fan on or off depending on the oil temperature.

Several Characteristics Make CPI Thermals Perfect for Heat Exchangers

According to Crozier, CPI’s SnapStat line of Thermals are finding their way into more and more heat exchanger designs for a number of reasons.

• Small Form Factor – AD series thermal switches like the AD197 can fit in tight spots with a surface mount footprint of less than 0.75 square inches.
• Extreme Durability – The basic SnapStat design is a double snap action design making them extremely resistant to vibration, shock and other modes of field failure. In almost every case, our switches will outlive your equipment.
• Standalone Operations – CPI Thermal Switch closures do not require external power or interpretation by central control circuitry. Thermocouple based closure/opening is guaranteed to happen based on set point every time, making them the ultimate fail-safe solution.
• Temperature Range – CPI’s SnapStat Switches have an operating temperature range of between 0F to 300F, easily covering the breakdown temperature limits of almost any modern lubricants.
• Readily Available Customizations – With CPI’s engineering ready to provide parts with your exact customizations you can fit our parts more easily into your manufacturing process and specific mounting requirements. Customer connectors, lead lengths, hermetic sealing, and double pole double throw options are all available.

For more information about any of CPI’s Thermal Switches contact John Crozier of CPI’s Application engineering team today to discuss your application.

Original content published: https://www.cpi-nj.com/cpi-thermal-switches-tried-and-true-for-aviation-applications/