DARA – AIRCRAFT HYDRAULIC RING MAIN SYSTEMS

 
DARA (Defence Aviation Repair Agency) have completed a state of the art Aircraft Servicing Facility at St Athan in South Wales. DARAawarded the hydraulic system contract to T A Savery, based in Birmingham UK, who under the direction of Mr R Peacock systems director, designed, manufactured and installed the complete hydraulic system.

ADVANCED HYDRAULICS SYSTEMS MONITORING

At the heart of the new DARA Aircraft Facility are the two state of the art Hydraulic Ring Main Systems that allow the Aircraft Hydraulic Systems to be fully functionally tested, filled, drained and flushed.

The Ring Mains are primarily designed to operate the Hydraulic Systems incorporated into Fast Jets that use either self pressurising reservoirs (Tornado, Eurofighter and Jaguar) or pressurised reservoirs (Harrier and Hawk).

The design incorporates the following philosophies, with safety of personnel being of paramount importance:

b)  Supplying a system that meets the Aircraft test requirements including the extremely tight tolerance bands on supply and return pressures as well as flows.
c)  Supplying a system to automatically meet the dynamic response required to test the Aircraft which has randomly varying loads. 
d)  Supplying a system requiring minimum operator input. 
e)  Minimising the operating and maintenance costs.
f)  Maximising the system availability and Mean Time between failure periods.

The Electronic/Computer System controls the interface parameters with the Aircraft and minimises the human input requirements by:

a)  The use of a Touch Screen Console adjacent to each Aircraft Interface Unit that allows programmable pre-set levels to be loaded for various types of Aircraft and types of test. 
b)  Matching the flow rates from the Powerpacks automatically via an algorithm to match the actual requirements of the Aircraft. This greatly reduces and minimises the operating costs as well as maximising the reliability.
c)  The inclusion of a PC based SCADA system to provide real time monitoring of the Ring Main Systems with historical data being gathered and stored on the flows, pressures, temperatures, operating times and sequences, etc to assist with monitoring and fault finding. This data can be displayed and printed in graphical or tabular format. 

System contamination monitoring is achieved by using an in-line particle counter. Incorporating the particle counters into the hydraulic system was achieved by using a software package called "Modbus ". This protocol enables the PML2 to be programmed to communicate with a Programmable Logic Controller. (PLC). This measures and reports the leanliness of the various aircraft hydraulic systems The technicians are able to view the cleanliness of the hydraulic fluid during all periods of servicing and testing, once the technician has finished the servicing, the aircrafts hydraulic systems can be checked that the correct operating cleanliness is achieved. Achieving and monitoring the correct cleanliness standards for the reliability of today's aircraft is critical.

Savery have engineered a standard proportional control circuit which complements the PB300.

Developed specifically for the Lift Market , it is suitable for controlling progressive raise and lower lift speeds.

The proportional Lift Control Circuit which has been incorporated into the ultra versatile PB300 Centre Adaptor uses a SP08-25 Normally Open and SP10-20 Normally Closed  Proportional Direction Valve  from the Hydraforce Proporrtional Valve range.

Offered is a comprehensive selection of recommended Electronic Controllers for various control solutions.  

Thermo Plastic Reservoirs are available in standard sizes from 1 to 4 litres to suit our range of 12 & 24 volt Mini-Pak series Power Units.

Reservoirs feature translucent oil fill indicators. Filler / Breathers can be located in a number of different positions, making these reservoirs suitable for both horizontal and vertical mounting.