Session 1: EMC Test Challenges for Military/Electric Aircraft

This paper provides an overview of the test methods employed in the HIRF certification of civil aircraft.  This addresses the full aircraft test methods rather than the equipment level test methods performed at bench level to RTCA DO160. Based on the experience gained over many decades of testing this paper provides both an overview of the full aircraft techniques and highlights some of the challenges with applying these methods to a range of different aircraft from large airliners to small business jets and more recently to autonomous aircraft.  The test methods discussed range from the low level coupling methods, known as Low Level Swept Current (LLSC) and Low Level swept Field (LLSF) to full aircraft High Level Radiated Susceptibility (HLRS), on-aircraft Bulk Current Injection (BCI) and Portable Electronic Device (PED) testing.

The methods are applied to aircraft at sites around the World and this paper considers some of the challenges associated with site suitability, licensing and access into the aircraft under test. As aircraft become more and more reliant on electronics and with the introduction of battery powered technology, the test challenges are increasing year on year.

Vertical Aerospace are developing an all-electric aircraft, the VX4. The aircraft is a tilt rotor aircraft capable of both vertical and conventional flight.

In order to achieve this, an initial aircraft has been developed (VA-1X) which will be used to evaluate the necessary design and flying qualities for this style of aircraft and  in the future will also be used as a test bed for new components.

The VA-1X prototype is a fully composite aircraft which was designed using COTS components from a variety of aerospace and automotive companies, which in some cases have not undergone the rigor of a full EMC qualification test program.

Clearly this prototype aircraft will never undergo a full HIRF certification program but to get the maximum benefit from this aircraft it will need to be flown to understand the transitional aspects of the flight program.

This paper briefly discusses the approach taken to develop the necessary HIRF clearances required to complete its flight test program.

This paper considers the challenges of performing E3 clearance on large military aircraft, covering factors including: the size and shape of the aircraft under test; access to and availability of appropriate test facilities; the required test levels, safety margins and how to achieve them; issues of access to aircraft systems; the potential Commercial-Off-The-Shelf nature of equipment; and, consideration of the new and/or legacy nature of an aircraft and its systems. Discussion on the potential for future modification of an aircraft and the requirements for further testing, as well as availability of an aircraft for testing, such as in-service demands, are also considered.