Following in the footsteps of the mammoth effort by
Gulfstream to get lowered approach minimums via an enhanced vision system on a
heads-up display, major avionics manufacturers are gearing up to pursue a
similar route for heads-down synthetic vision systems.
Though several "strategic" synthetic vision systems (SVSs)
are currently available on the market as situational awareness enhancers,
including Chelton's FlightLogic and Universal Avionics' Vision 1, companies
like Honeywell and Rockwell Collins will attempt to transform SVS to a
"tactical" device to gain operational credit— primarily lower approach minimums— for
operators who equip and specially train with the new equipment.
Judging from the effort that Gulfstream and its partner
companies went through to get lowered minimums using an optical-based enhanced
visions system (EVS) tuned to runway lights— it took about two decades from
start to finish, including more than three years of certification testing— doing
the same thing for a database model of the outside world will likely be more
difficult. The gain could be worth the pain, however. Operators using the
Gulfstream forward-looking infrared (FLIR) camera-based system and the
appropriate training program are able to lower their Category I decision height
minimums from 200 ft to 100 ft.
Tim Rayl, senior director of business and regional systems
marketing for Rockwell Collins, says the company's efforts in SVS will be aimed
at getting "credit" for lower minimums. Rockwell Collins has been heavily
involved in research in the area for the past few years, in partnership with
NASA, the FAA and "key" original equipment manufacturers. Here at NBAA, Rayl
says he'll "very, very likely" have some of the company's SVS hardware and
software on display behind the scenes, but by invitation only.
The company last year flew developmental algorithms and
hardware onboard a Gulfstream V as part of a NASA SVS test in Reno, Nev. In the
test, Rockwell Collins engineers studied the usefulness of various
highway-in-the-sky (HITS) concepts with guest pilots behind the yoke and
investigated techniques for validating the integrity of an SVS database, an
area of much concern for the FAA. In particular, the company used a modified
version of its WXR-2100 weather radar to verify that the aircraft's
GPS/WAAS-derived distance to terrain in the database matched with what WXR-2100
measured.
Rayl also notes that Pro Line 21, the company's newest and
most advanced flat-panel display cockpit, was designed with SVS in mind. "We've
added processing capabilities, interface capabilities and architectural
decisions that are all aimed at supporting SVS," he says. "We originally
envisioned SVS for Pro Line 21 down the road."
Rayl says the new system is probably five years from
certification for FAR Part 25 aircraft. "Certifying a new technology like this
for tactical operations is going to be a long and very detailed process," he
says.
One of the big issues will be database validity. Based on
the WXR-2100 work, the company is considering using various sensor inputs to
validate that the terrain is really where the database says it is. The sensors
will also be used to map out real-time changes to the environment— for instance,
when an aircraft or vehicle is blocking the runway. Rayl says the final product
may include both SVS and a FLIR system, with the FLIR being used for "what's
really in front of you" and the SVS for "what's farther away."
Likewise, Honeywell engineers are quietly working behind the
scenes on an as-yet-unnamed SVS product. With vast experience in terrain database
management and verification through its EGPWS work, Honeywell's primary effort
at the moment is figuring out the best way to display information to the pilot.
Chad Cundiff, displays and crew interface portfolio director
for Honeywell, says the company's approach will incorporate lessons learned
from heads-up display applications in order to make its heads-down displays
"more intuitive," reducing scanning time and increasing operations efficiency.
He says the company has tested the displays in flight tests with company
aircraft.
"We want to replicate the world the pilot would see out his
cockpit window," Cundiff says. Such a replication hints that Honeywell won't
adopt HITS. "HITS introduces non-aviation symbology," says Cundiff. "When you
fly along, you don't see boxes in front of you." Cundiff says there's "well
documented" research that suggests HITS can give pilots a form of tunnel vision
that may decrease situational awareness.
Like Rockwell Collins, Honeywell is also considering
infrared devices as a companion technology for a comprehensive SVS.
