One of the biggest challenges in
studying Enhanced Flight Vision
Systems (EFVS) in helicopters is the
subjectivity of pilots. In other words,
depending on their experience,
proficiency and personal preferences,
different pilots will respond differently to
To make a fair assessment of the
effectiveness of the various EVS
(enhanced vision systems) technologies
they are studying the FAA must take
account of this variability in pilot
experience, says lead researcher Cliff
Johnson. He says, “We’ve just been
testing with FAA test pilots so far to get
comfort and familiarity with the device
but later on we plan to bring in outside
pilots. Either from the FAA, government
or industry folks that have experience in
Budget limitations mean the FAA
won’t be able to recruit a large sample
group of pilots. But Johnson
says there are ways
to circumvent this
limitation with the
structure of the test.
“If you intersperse
your subjects and randomize your
design that gives you a good crosssection.
Even in the small sample we’ve
used we’ve seen some differences
based on the different pilots.”
The biggest difference they have
noted has been linked to whether the
pilot has prior experience with headworn
equipment or not, says Johnson.
However Tal Golan, rotorcraft
business development manager at
Universal Avionics, says the technology
is so intuitive that differences based on
experience quickly fall away.
“The only advantage a prior user will
have over the non-user will be a few
hours of flight time, until they can
fully take advantage of such a device,”
“We have seats in the back for the flight test
engineers. We also have a GPS receiver on the
helicopter to pull satellite data that gets us down to
sub-one-meter accuracy for the position of the aircraft.”
The video feed from the EFVS sensor’s video feed is
routed to the back of the cockpit where it is recorded.
Johnson’s team then have the option to replay the video
feed to other pilots on the ground in a laboratory
environment, expanding their pool of test subjects.
Most of the testing is taking place in the air. “It’s very
hard to simulate the sensor returns,” Johnson says.
During the flight tests an FAA-test pilot with a headworn
or head-bound display flies multiple approaches in
varying test conditions. “It might be a normal approach to
the helipad with the EVS and symbology on. We’ll ask the
pilot to say when they see the various visual elements.
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“We’ll start by testing
their performance with
no enhanced vision. Then
we’ll added basic flight
symbology such as air
speed, altitude, rotor
torque and RPM.
Information that you would
have on your instrument panel but now you’re able
to see on the head-worn display.
“Then we add EVS and run the test again. Then we
do it again with SVS and then with CVS.”
Following the test flights pilots are asked to fill in
questionnaires which help Johnson’s team assess the
ergonomic effects of the EFVS technology.
In relation to ergonomics, another potential
challenge with EFVS is information overload. In other
words “what is the right level of symbology that might be
needed to inform certification,” says Johnson.
The program is also investigating the viability of
vision technologies outside of the mainstream market.
Johnson says, “On the helicopter side we have the
added challenge of flying into phenomenon like
maritime fog, where there are limitations to infrared
systems. So, we’ve taken the forward-looking step of
looking at other systems like millimeter wave radar and
VISUAL DATA MIX
Johnson anticipates that the final version of EFVS in
helicopters will probably be “a blended approach” of
combinations of EVS technologies that could vary
according to the specific use.
“We’re trying to let it be performance-based, so we’re
trying not to say you have to have infrared or Lidar. But
rather we want people to select the best technologies for
their particular use.”
When the study is complete Johnson’s findings will
be passed to the FAA’s Office of Aviation Safety and its
Office of Aircraft Certification, who will develop the
operational rules and criteria for use and certification
respectively. However, this final certification step is
some way off, he says.
“We’re about in the middle of the study. On the fixed
wing side it took ten years for certification. Hopefully it
won’t take that long for us. We’ve made a lot of progress
but we still have a way to go.”. \\
5 // Tal Golan, rotorcraft
manager, Universal Avionics
6 // The Max Vis enhanced
vision systems increase the
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