October 14, 2013
Credit: Rockwell Collins
Avionics and head-up guidance system provider Rockwell Collins is developing a passive, uncooled multi-spectral vision aid that will see “first light” by early November, marking a key benchmark in the company's bid to become an end-to-end enhanced flight vision system (EFVS) provider.
Though primarily used by high-end business aviation and cargo airline FedEx, enhanced flight vision systems are poised to enter the mainstream airline market as a result of a new FAA rulemaking. Competition among EFVS providers is expected to increase, driven in part by the FAA action and China's declaration last year that it will equip its entire airline fleet with the technology by 2025.
With a certified EFVS, including a head-up display with navigation guidance and video from a forward-looking imaging sensor, pilots on a precision-instrument approach, which normally has 200 ft. minimums, can use the sensor in lieu of natural vision to descend as low as 100 ft. above the runway threshold. At 100 ft., the pilot must visually discern the runway lights or other identifiers to continue the approach.
The FAA is proposing that pilots of EFVS-equipped aircraft with the proper training and currency be allowed to continue descending and landing using the EFVS, boosting airport capacity. The proposed rules, published in June, would also give airlines relief from the so-called approach ban, which prevents aircraft from starting an instrument approach if the reported cloud ceiling and visibility at the airport is below minimums for it.
The revelation of Rockwell Collins's new sensor was not surprising from a strategic standpoint, given the FAA rulemaking and China's EFVS goal. What was unexpected was the decision to build an uncooled multispectral sensor as the core of the new EVS-3000, diverging from industry norms of using more expensive cooled sensors for systems certified for lower landing minimums. The new sensor is being developed at the company's Portland, Ore., facility where it has built and delivered more than 5,000 head-up guidance systems, a portion of which are incorporated into EFVS systems with Elbit-Kollsman or Esterline CMC cooled infrared cameras.
Though the FAA notes that the imaging cameras may be based on forward-looking infrared, millimeter wave radiometry, millimeter wave radar or low-level light intensification, all certified systems to date are in practice using cooled sensors operating in a portion of the short- and mid-wave infrared spectrum (1.2-5 micron range). That spectrum was selected so that the sensor would pick up the reflected infrared (IR) and thermal energy in the short- and midwave infrared spectrum radiating from incandescent runway and approach lights, giving pilots the cues they would normally see through the windscreen. The sensor is optimized to cover four types of airport lighting and is cooled to boost its ability to register very slight (0.1 deg.) temperature differences in a scene.
The future of those incandescent lights is murky, as airports begin transitioning to LED lights to cut electricity usage. The FAA is studying possible alternatives for runway approach lights, including LED lights augmented with IR emitters. For operators who have equipped with EFVS, including FedEx, the possibility of the FAA switching to LED lights is spawning fears of EFVS becoming “million-dollar paperweights.”