EMC in the Viggen Aircraft

The Viggen is a combat aircraft built by SAAB Aircraft Company in Sweden. The first production aircraft is scheduled for the middle of 1971. The third prototype aircraft, containing the complete electronic system made its first flight in April this year. The EMC program is based on sound design, measurements of subsystem characteristics and system tests in a mock-up. Much importance is paid to good aircraft installation. For instance susceptible and interfering wire bundles are separated. The blackbox design is continuously monitored by the maincontractor. Instead of prescribing limits for the subsystem measurements the test results have been collected and combined by the main contractor. In case of obvious interference special measures have been taken. The measurements also serve as support for the system tests. The system tests are made in a mock-up with the same electromagnetic configuration as the aircraft and include marginal measurements. Some measurements are also made in the prototype aircrafts. The subsystem measurements are completed and the system tests in the mock-up and in the third prototype aircraft are now going on. The results are promising so far.