Copyright © 2020 Xflight Technologies LLC, Florida, USA
3
A. Introduction
The XF-160GL3 produces a double exponential voltage / current pulse intended to give
confidence that a design can pass DO160G and MIL-STD-461G conformance / Qualification
tests. DO160G is the RTCA Inc. Environmental Conditions and Test Procedure for Airborne
Equipment. It is a very important aviation industry specification and used throughout the
industry to qualify any equipment prior to it being allowed to fly on commercial aircraft.
Section 22 relates to Lightning Induced Transient Susceptibility testing. It defines certain
waveforms that must be applied to any unit under test (UUT). Two types of application of
simulated lighting energy are described.
(i) Induced. This is where the energy it transferred to the UUT via induction into cables
connecting signals and power to the UUT. (The cabling to be as similar to a real
installation as possible).
(ii) Direct pin injection. A test probe is connected, in turn, to each connector pin that
allows any signal or power line to connect the unit to the aircraft.
Of the two cases above the direct pin injection is considered to be the worst case since all
the energy is concentrated onto a single pin / signal. Furthermore, of the different types of
waveform, the one considered to be the worst case is the double exponential (see appendix
A(5)(b). The rise time and fall time of the pulse is important. This defines the pulse width
and so the amount of energy that can be transferred to a UUT. For high impedance signals
that effectively deflect the energy back to the source, the pulse width defines for how long
a high voltage is present on the interface. The XF-160GL3 supports a waveform very similar
to the DO-160G waveform 1 (WF1) and waveform 4 (WF4). WF1 is a current waveform for
low impedance signals where it is not possible to meet the voltage requirement. WF4 is the
voltage waveform.
DO160G defines different levels of energy (Level 1 being the weakest and level 5 the
strongest). The level needed depends primarily on the equipment function (i.e. critical or
not) and the installation location. (There is also a dependence on any electrical connections
to other parts / equipment on the aircraft).
The XF-160GL3 allows for confidence testing of WF1/4 to level 3 as shown below.
* Voc is peak open circuit voltage. Isc is peak short circuit current.
Level 3 waveforms and levels are generally for non-critical equipment inside the aircraft,
such as in the Electronics bay.
