The Cool City digital flight guidance computer (DFGC) is the heart and soul of the automatic flight control system. The DFGC contains the latest in electronics technology with surface-mount printed circuit boards (PCBs), solid-state sensors, accelerometers and air transducers. Cool City uses the latest in surface-mount technology and electronic hardware to provide high reliability and RF interference resistance.

Cool City makes use of a single chassis for the electronics of the system. Each box is configured for the system to be installed; however, should you choose to update the system later, it is accomplished by the addition of the requisite internal PCBs.
Although all system PCBs are located within this one box, the autopilot and SCAS are independent and each has their own power source and internal power supply. The DFGC is tray-mounted outside the cockpit; therefore, installation in the cabin area has a very small footprint.

The tray for the DFGC contains a configuration module to store all airframe related specifics, which are downloaded by the DFGC each time at start-up. By utilizing this method, the DFGC remains generic with regards to different airframes. This allows operators of multiple helicopters to keep a single DFGC spare that may be used in many different airframe models with the same system installed. The tray also contains the air transducers; therefore, removing and replacing the DFGC does not require entry into the pitot-static system.

The DFGC contains 3-axis orthogonal, solid-state rate sensors, as well as an integral yaw-axis rate sensor and a long-term slip-skid sensor. The DFGC will interface with essentially all attitude systems for attitude data, ADAHRS from electronic flight instrument systems, AHRS, and/or the air data computer that have autopilot outputs.

Any failure of external data used by the autopilot causes the DFGC to revert to the internal rate package so you do not lose autopilot functions. This reversion occurs seamlessly; however, it is annunciated on the AP Controller by the annunciation of RATE.
The DFGC has seven ‘receive’ and one ‘transmit’ ARINC 429 ports, a CAN bus port and analog interfaces for connecting to the aircraft systems. The DFGC also contains a digital data recorder function which records up to 48 channels of information in a 28-minute loop.

Additionally, the computer contains a bi-directional CAN port for diagnostics that can be used with an external recorder for continuous recording of operations for Flight Operations Quality Assurance (FOQA).

The DFGC has been tested to the latest DO-160 environmental qualifications, against HIRF and protected against lightning, to ensure it meets the standards established by Cool City and the FAA and, more importantly, the expectations of you…the customer.