HUMS – Health and Usage Monitoring Systems is a generic term given to activities that utilize data collection and analysis techniques to help ensureHUMS – Health and Usage Monitoring Systems is a generic term given to activities that utilize data collection and analysis techniques to help ensureavailability, reliability and safety of aircraft/helicopter engines, important flight data and parameters.
It comprises of three different units alltogether monitoring the actuall status of the aircraft/helicopter data. It is the HUMS AS 10 MPU – Main Processor Unit, the HUMS AS 10 CDU -Control Display Unit and the HUMS AS 10 DTU – Data Transfer Unit.
The monitoring system consists of two main parts. Hardware analog/digital converter for both Russian/USA systems, data collector and storage with a data analysis software evaluating received categorized data with amobile or front-end application as well.
Unique 7-bit number, according to which the MPU knows which aircraft – helicopter it is installed in. The aircraft – helicopter ID is loaded when the MPU is started, checking if stored calibrations and the statistics are valid for the aircraft – helicopter. If the aircraft – helicopter ID differs, the default calibration is loaded and the current flight is not added to the saved statistics. Assigning the current aircraft – helicopter ID to calibrations and statistics will occur when the “RESET.” SYSTEM DEFAULT ”which is available via the service menu.
Turbine and rotor speeds are measured from the signal frequency of the tachogenerator. Data is stored on CF card every 96ms. The stored value is the average of the last 4 measured values. Pulse is also the current fuel flow is received.
Analog data is stored on a CF card every 96ms. These data are the average out of the last four samples that load every 24ms. Exceedance occurs when the parameter value exceeds above or drops down the limit.
Digitally received data from Cargo Hook and Hoist. Cargo Hook sends cargo weight on the hook and Hoist sends the length of the unrolled rope in meters.
Discrete inputs are sampled every 6ms and the last 16 samples out of the diameter are stored to the CF card every 96ms.
Data from Air Data Computer
The aerodynamic control panel is connected with static and dynamic pressure from the pitot probe and ambient sensor temperature. The control panel has a fixed Baro potentiometer set to standard 29.92 conversionheight inHg. The control panel is also configured to measure IAS speedup to 40kts. Data from the control panel is being sent after Arinc429 to the processor, it stores them every 96ms.
Rotor torque is the sum of the torque of the left and the right engine.
Fuel Flow Sum and Fuel Used
Fuel flow sum is the sum of the fuel flow for both engines. Fuel used is the total amount of fuel which was consumed during the flight. If the current fuel quantity is greater than zero, then from the amount consumed.
Delta NG expresses a “performance reserve”. The NG delta value is dependent on the engine speed NG a temperature and air pressure.
VNE is the limit value for IAS. VNE is dependent on the ambient air temperature OAT (Static air temperatuere) and Altitude (Pressure Altitude).
Termination of the exceedance occurs when the hysteresis limit is exceeded. Start date and time the duration and maximum (minimum) value of the parameter during
the duration of the exceedance are stored and expoerted as the Exceedance List Table.
List of Events
OEI, Engine Start, Engine Cool, Engine Run, Engine Abort, Engine Spool, Engine Stop, Landing, Take off, Battery charge, Bleed heater, Bleed valve,
Power OFF, Recording.
Cool and spool Count
If at least one engine is in the cooling phase, the CDU screen is displayed with by counting down how much time remains until the end of cooling. Cooling time is 30s. If at least one engine is in the spool phase and there is no countdown on the CDU cooling, the spool time is displayed.
Hoist cycle is used for counting winch usage. When the winch is rotated, pulses from the Hoist cycle switch are being generated. These pulses are
added to the hoist cycle parameter. At the same time, these pulses are added to the Total Hoist Cycles statistics.
NG and NP cycles
The number of reference cycles consumed between one start and the consecutive shutdown.
If there were any exceedances during power on, then after landing and stopping the engines a the main rotor, Flight log appears on the CDU. In these screens, the exceedance is displayed first that occurred during the flight and are related to the airframe. Then, if so, the exceedance for engines. You cannot view them again when you exit these screens.