Dassault Aviation: Software offers benefits beyond precision measurement

Dassault Aviation, the French aircraft manufacturer, has improved its test equipment for the development of its Falcon business jets by using HBM's data acquisition and analysis equipment.

During ground tests digital data transmitted by the aircraft has to be compared with readings transmitted from analog sensors sited on the ground test installation to validate and ensure the aircraft’s systems comply with regulations.

HBM’s equipment can acquire both the analog and digital parameters coming from the ARINC 429 standard avionics buses to improve accuracy and make these tests faster.

The ARINC 429-11 "Mark 33 Digital Information Transfer System (DITS)" standard describes a particular type of bus used by onboard avionics equipment and systems in more than 10,000 commercial aircraft worldwide. Avionics equipment transmits onboard data digitally, and the ARINC 429 standard specifies the electrical interfaces, the signal format, labels and discrete data together with the protocol for messages exchanged between different equipment. This data is logged digitally by means of an ARINC 429 acquisition card.

However, certain development tests for the Falcon series - which includes the Falcon 900C, the Falcon 900EX, the Falcon 2000 and the Falcon 2000EX - require the simultaneous and synchronised acquisition of analog and digital parameters. This synchronisation is needed to achieve precise correlation of information transmitted on the aircraft's buses and the data coming from the "ground" test instrumentation. In testing, this makes it possible to prove validation and compliance of the aircraft's system.

By using HBM's catman^®, Dassault Aviation is able firstly to capture both digital and analog data streams in real time and secondly to generate computation series. In order to enable dialogue between catman^® and the ARINC acquisition card, it is necessary to make catman® compatible with its API interfaces. An API interface enables programmers to access pre-built software modules through defined data structures and subroutines.

Notes Bernard Elissalde, Chief Inspections Engineer in Dassault's flight test Quality Control Department: "I would go so far as to say that catman^® is more than a software program capable of performing measurements; it is a software program which makes it possible to perform tests".

He adds: "For several years we have been working in conjunction with HBM, and they have always been available to note our requirements and technical constraints, so as to provide an optimum solution”.

Mr Elissalde feels that catman^®'s multi-level design has numerous advantages for Dassault Aviation. It is easily and intuitively configured and commissioned so that any desired measurements can be quickly secured. Experienced users can also exploit the wide range of functions offered by the program for the creation of more complex applications by programming individual scripts.

When used with HBM's MGCplus, catman^® guarantees metrological traceability, which Mr Elissalde says is always very useful.

Dassault's metrology department relies extensively on HBM's equipment; it utilises 45 displacement sensors and 45 load sensors along with a torque measurement instrument. It also uses an DMC9012A and a UPM60 together with eight HBM MG3150 amplifiers to amplify the signal.

Furthermore, two MGCpluses used in conjunction with a certain number of diverse cards provide the basis for its acquisition resources. The cards used by Dassault include three ML38 high-precision, single-channel modular cards, six ML30B cards, five ML801 cards and a single ML60B card.

Dassault also uses an ARINC 429 card for the transmission and reception of ARINC signals during the tests.

Mr Elissalde notes: "We have used HBM's equipment successfully for nearly 30 years. It enables us to perform our measurements with a very high degree of metrological quality, with particular reference to load measurements when weighing our aircraft. This is thanks to the very good characteristics of the Z4 and Z12 sensors as well as the quality of the associated amplifiers".

HBM's load transducers are used for weighing and centring measurement operations on the Dassault Aviation aircraft and their sub-assemblies. Adds Mr Elissalde: "I am also convinced that the combination of MGCplus and catman® has a long career ahead of it within our ‘Flight Test’ site".