NASA considers windowless flightdecks
Designers plan external vision systems for supersonic cockpits.
Test engineer Mark D'Aprile checks out a small needle-nosed model of a Gulfstream supersonic jet concept mounted in the Langley Unitary Wind Tunnel.
Honeywell demonstrated component level feasibility of what NASA called its external visibility system (XVS) program. The XVS had to perform 3 crucial functions— avoid collisions with other aircraft, land the aircraft in all weather regardless of external visibility, and perform safe ground operations.
Honeywell research with NASA Langley also included lipstick-size cameras tiled together to make a big display, with tests in the NASA Ames vertical motion simulator—the same device used to train Space Shuttle pilots.
Gulfstream, in collaboration with NASA on the XVS program, conducted a series of studies to identify key display and control issues if the front window were totally replaced with high-definition displays.
Some of the tests, flown on a NASA Dryden F18 by Gulfstream test pilots, included limited HUD symbology to evaluate all phases of flight, based solely on the view of the hi-def display. Operations with the prototype XVS were shown to be smooth for all operations, including following the yellow taxi line to the ramp and parking.
NASA Langley, Honeywell and Gulfstream also recently completed a significant test and evaluation of both EFVS and SVS operations in actual low visibility. These tests were in support of FAA rule development for vision systems, and the flight experiments included sample pilots from both industry and the military.
Test data analysis focused on the pilot's ability to fly and land manually in conditions of extreme low visibility. Early test data showed that for both the instrument segments and EFVS "visual" segments, pilot control and safety of the operation were all normal.
Bombardier, a key player in advanced vision flightdecks, has ramped up its implementation of Global Vision Flight Deck with EFVS supplied by CMC Esterline and the Pro Line Fusion avionics and HUD supplied by Rockwell Collins.
Bombardier recently became the first to gain FAA certification of synthetic vision on the HUD, and is in the process of further expanding Global Vision's operational envelope.
The company's experiments with SVS and sensors for maneuvering in all phases of flight are safety driven to improve pilot awareness of the terrain and the airport, and to improve a pilot's accuracy.
Rockwell Collins has also been a long-time partner with NASA Langley in experiments on advanced SVS flightdecks. Studies included PFD formats, size and shapes, and actual flight tests on several aircraft including an FAA Boeing 727 and a NASA Boeing 757 and Gulfstream V.
Universal Avionics' advanced design of SVS is attacking the basics of the database seen on the PFD.
The problem comes in 2 parts, and parallels the progress of computing and advanced display technology. The higher the image quality, the more lifelike is the terrain and other features.
The tradeoff, of course, is more graphics and computational power—or your flight display slows to the rate of an old and buggy computer game. One of the advanced display concepts Universal is exploring for supersonic flightdecks includes showing the footprint of a sonic boom area. Universal's designers have magic, and are also key players in SC213.
Vision systems for zero-viz ops
Lynda Kramer, a principal researcher in NASA's Flight Deck Interface Technology Group, demonstrates SVS and HUD technology.
FAA's official definition of an EFVS is "an electronic means to provide a display of the forward external scene topography (the natural or manmade features of a place or region especially in a way to show their relative positions and elevation) through the use of imaging sensors, such as a forward looking infrared, millimeter wave radiometry, millimeter wave radio, low light level image intensifying."
Key here is that FAA has stated that an EFVS can be the means by which the pilot can officially see in low visibility. FAA and industry's goal is to extend the visual segment of an instrument approach, which means only typical instrument guidance is required, and at published minimums you see with EFVS or the naked eye. For ultimate system operation no natural vision is assumed, and all the operation is conducted with EFVS.
Special Committee 213 designers and FAA have identified the key elements of a vision-based flightdeck for operations in an environment where no natural visual cues would be available to the pilot. Vision system designs span a range of corporate and large commercial air transports.
The new designs factor in the type of instrument approach and guidance, airport light structure, runway dimensions, runway centerline lights, etc.
The primary requirements that have emerged are that the HUD or equivalent display show the sensor imagery, and that aircraft flight symbology and other cues need to be conformal to the outside world.
Bombardier Test Pilot Mark Schlegel with Global Vision Flight Deck (GVFD) test rig used for EVS, SVS and combined vision systems development.
The new requirements also note that other display methods may be acceptable if equivalent levels of performance and safety are demonstrated.
There is also a requirement for an independent EFVS for use by the pilot monitoring so that control of the aircraft can be transferred.
The combined sensors must be shown to operate in low-visibility conditions without interruption due to weather. The EFVS may augment the pilot's natural vision of the taxi and ramp surface as well as signs, lighting and markings.
FAA's POC test
Six new operational advances have been identified and are part of FAA's proof of concept (POC) activity related to ongoing certification programs. For many organizations a POC is performed in the experimental "will it work?" phase.