The FAA issued a final rule today outlining new processes that will allow pilots flying airplanes equipped with enhanced flight vision systems (EFVS) to fly certain IFR approaches all the way to landing “in lieu of natural vision” from the previously allowed elevation of 100 feet above touchdown zone. What this means is that EFVS-equipped airplanes now have greatly improved utility.
Current rules allow descent to 100 feet on some approaches when using a head-up display (HUD) and enhanced vision system (EVS, generally infrared imaging). Under the new rule, which becomes effective March 13, 2017, pilots flying with EFVS will be able to continue those approaches to landing using only the images displayed by the EVS on the HUD.
The new rules are quite flexible and, in fact, don't specify that a HUD is even required for the pilot flying. This is to pave the way for future technologies that might not be HUD-based, such as wearable displays or other methods for delivering flight symbology and EVS imagery to the pilot flying, who must still be able to look forward through the windshield. The rule does require, in aircraft with more than one pilot, that the pilot monitoring have a display showing EFVS imagery, but this does not have to be a HUD. "The FAA is not adopting the requirement for the pilot-monitoring display to be located within the maximum primary field of view of the pilot monitoring," it said.
Added benefits of the new final rule are that it opens up EFVS approach capabilities at more runways with a larger number of approach types, applies it to Part 91, 91K, 121, 125 and 135 operations and allows commercial operators to dispatch when destination weather is worse than currently allowed, including initiating and continuing an approach when visibility is below minimums. This should help reduce ground-stop delays due to below-minimums weather at the destination, for airline aircraft that are EFVS equipped and with appropriately trained flight crews.
There are training and airworthiness requirements under the new rule, and a letter of authorization is still required for EFVS operations. To remain current in EFVS operations, pilots must have logged six approaches using EFVS in the past six months, in any weather conditions, day or night, including one to a full-stop landing using EFVS. The training and currency EFVS flying can be done in a level-C or -D flight simulator.
The FAA's discussion of the new rule also addresses combined vision systems (CVS), in which EVS and synthetic vision imagery is combined on a display such as a HUD. According to the FAA, “A CVS consisting of an enhanced flight vision system and synthetic vision could be approved for EFVS operations if it met all the requirements of the EFVS regulation.”