HOW CDB PROCESS WORKS?

The concept of operation is simple, there are accelerometers and other sensors temporarily placed in designated locations along the drivetrain in order to measure components RPM, vibration level and other data required. The aircraft is then run on the ground and measurements are taken. Using complex algorithms, the computer then analyzes the information, calculates a solution, and displays it to the technician. The technician follows the solution instructions and take the required steps to balance the drivetrain.

After applying the solution, a verification run is performed to confirm the reduction in vibration. Then, the sensors are removed along with the special cables and the aircraft is returned to service. The entire process takes an average of two to four hours for the first balancing run. Subsequent runs historically take much less time, sometimes as little as 30 minutes.

DO YOU HAVE DATA HISTORY THAT SHOWS THE BENEFITS OF CDB?

CDB is successfully used by an international fleet of rotary wing aircraft and has achieved more than 3 years of proven performance. Immediate benefits of before and after results and long term benefits of improving cost saving, safety and mission readiness can be sent upon request.


CAN CDB INTEGRATE WITH CURRENT MONITORING SYSTEMS?

CDB is a CBM enabler in that it compliments existing data source collectors such as Health Unit Monitoring Systems (HUMS) and Modernized Signal Processor Units (MSPU). CDB could be integrated into these and other monitoring systems in the future as needed, thus increasing the capability of such systems.

The critical part of the CDB system is the software. Integration effort would mostly involve software integration engineering. The hardware requirements for the CDB process are mostly common items readily available.

There are few options to acquire data for processing, one of which can be from current system (assuming data is collected from the same data points and RPM). During CDB run, data will be collected from current system and CDB algorithms will provide with balancing solutions. Another path will be to download data from current software and the CDB system will analyze and provide with solution if needed.

Depending on the needs of our clients, our engineering department can define the integration requirements and develop a path for a seamless integration with current and future planed solutions


WHY DO CDB DURING A GROUND RUN INSTEAD OF AIRBORNE?

The vibration data transmitted through the aircraft when on the ground gives a much more precise vibration profile, eliminating the differences of changing torque loads on drivetrain components in flight. These changing torque loads distort the measured vibration levels resulting in a misleading picture of the drivetrainʼs condition.

During a ground run, minimum torque is transmitted through the driveshafts vs. heavy torque load on the main rotors and drivetrain components during flight. Additionally, torque levels transmitted while airborne are changing due to flight conditions; therefore vibration levels are changing constantly. Onboard monitoring systems recording vibration data on the ground and in the air confirm these vibration changes as torque levels change.

During the CDB process, (verification stage) the pilot is asked to increase the collective 20 percent and it is verified that the vibration data transmitted is decreasing - due to the increase of the torque on the components. When the CDB process is completed, the vibration levels are low (significantly below limits) and when the aircraft is in flight the vibrations are reduced to farther. (See pilots / users testimonials)

As an example, when vibration data is collected in the regular spectrum through an accelerometer at either hanger bearing area, one set of vibration levels is seen. When the pilot increases the collective, the vibration levels dramatically decrease. Also, users would agree that when aircraft is descending (reduction of torque) vibration level increases.

Finally, the unbalanced point of the component is changing location along the component depending on the torque levels transmitted through the component. Usually, the shafts are unbalanced at many location points. The distribution and quantity of mass unbalance are random quantities. When the shaft is transmitting a torque, it creates a twist on the component. The twist of the shaft is changing the position/location of the mass unbalance point/position


AT WHAT POINT DO I START TO SPEND MONEY BECAUSE OF COMPONENT VIBRATIONS? (‘THE SPENDING POINT'). AND IS IT POSSIBLE TO PUSH THAT POINT FARTHER AWAY OR COMPLETELY ELIMINATE IT?

Aircraft owners agree that component vibration levels are deteriorating over time. Some aircraft platforms have monitoring systems that quickly become part of the maintenance process to try and identify or even solve vibration problems. (Where, when, why, etc..). When the onboard monitoring system is alerting for high vibrations, the maintenance procedures instructing the soldier to check a few options with the intention to try and find the root cause of the problem. At one point ('the spending point') the procedure calls for part replacements (before their TBOʼs) as another option to “try” and solve the problem. In most cases, the unit will replace parts until “they get the right combination of drive train components” and the indicators will confirm that the vibrations are reduced.
What is happening is that the root cause of the vibration problem is not eliminated, the vibration is just “reduced temporarily” by compensating for part replacement and the change contributes to the balancing of the aircraft. Since the root cause of the problem still exists, the vibration indicator will soon show high vibration and the unit will replace parts again.
So, at one point (“the spending point”) a maintenance process calls for component replacement as a way to try to solve vibration problems and put the aircraft back in service.
When the CDB Solution is applied, the entire aircraft is balanced and vibrations are reduced to very low limits by “eliminating the root cause of the problem”. Under these new conditions, when the aircraft is flying more hours, the increase of vibration is less dramatic (very low vibration deterioration rate) and always below limits, therefore the aircraft never reaches the “spending point”. Furthermore, in order to ensure that the aircraft will never reach the spending point, a CDB application may be applied every 250 flight hours and be part of routine maintenance process.


WHAT IS THE PROCESS TO DEVELOP CDB FOR A NEW PLATFORM?

CDB can be applied to all rotor wing platforms and all services to include paramilitary and commercial application with very little algorithm software modification. CDB will improve reliability of aircraft by reducing destructive vibration that causes system components to fail prematurely. Additionally, CDB technology is transferrable to the AH-64 Block III configuration.

CDB will serve in the Joint arena with ease, as it is easily adaptable to other rotary wing platforms.

Basic steps to develop:

 - Measure components and study trends
 - Collect platform vibration profiles
 - Analyze profiles for algorithm establishment
 - Refine algorithm for upload into computer platform for fielding
 - Perform balance with one ground run for data collection and corrective action
 - Set CDB interval based on the current schedule inspection criteria.
 - Set possibility for future integration with any of the Data Source Collectors (HUMS/MSPU and others)


HOW CDB CHECKS FOR SENSORS ACCURACY?

During the CDB process, data is collected from the additional accelerometers temporarily placed in designated locations along the drive-train. Using the CDB harness connected to the computer, data is also collected from the onboard SPU accelerometers at the IGB and TGB locations, which will show the data transmitted via the onboard SPU sensors and wiring. Using proprietary algorithms, the CDB computer considers the vibration and modulation conditions and is able to alert in case of unusual/unwanted conditions. The CDB system is able to detect and provide maintenance instructions to resolve the identified deficiencies. Examples are:

• Sensors are checked as described above and found to be serviceable, but the CDB system detects a high vibration from the SPU sensors and the alert system is not illuminating. The system gives instructions to check the wiring from the SPU box to the sensor as well as the power and the SPU box itself.

• Sensors are checked as described above and found to be serviceable and the aircraft vibrations are within limits, but the SPU VGB light is illuminated. The CDB system instructs the technician to check the electricity around the SPU box and recommends sending the SPU box for calibration. Generally, the CDB system recommends checking the integrity of the SPU box every 6 months.