Preventing runway incursions is considered a top safety priority for the National Transportation Safety Board and is a
growing problem among commercial air traffic at controlled airfields. This problem only increases in difficulty when the
weather and airfield conditions become severely degraded. Such is the case in this Air Force Research Laboratory
(AFRL) work, which focused on the decision making process of aircrew landing under near zero-zero weather at an
unimproved airfield. This research is a part of a larger demonstration effort using sensor technology to land in near zero-zero
weather at airfields that offer no or unreliable approach guidance. Using various head-up (HUD) and head-down
(HDD) display combinations that included the sensor technology, pilot participants worked through the decision of
whether the airfield was safe to land on or required a go-around. The runway was considered unsafe only if the boundary
of the runway was broken by an obstacle causing an incursion. A correct decision is one that allowed the aircrew to land
on a safe runway and to go-around when an incursion was present. While going around is usually considered a safe
decision, in this case a false positive could have a negative mission impact by preventing subsequent landing attempts. In
this study we found a combination of display formats that provided the greatest performance without making significant
changes to an existing avionics suite.
When flying an airplane, landing is arguably the most difficult task a pilot can do. This applies to pilots of all skill levels particularly as the level of complexity in both the aircraft and environment increase. Current navigational aids, such as an instrument landing system (ILS), do a good job of providing safe guidance for an approach to an airfield. These aids provide data to primary flight reference (PFR) displays on-board the aircraft depicting through symbology what the pilot's eyes should be seeing. Piloting an approach under visual meteorological conditions (VMC) is relatively easy compared to the various complex instrument approaches under instrument meteorological conditions (IMC) which may include flying in zero-zero weather. Perhaps the most critical point in the approach is the transition to landing where the rate of closure between the wheels and the runway is critical to a smooth, accurate landing. Very few PFR's provide this flare cue information. In this study we will evaluate examples of flare cueing symbology for use in landing an aircraft in the most difficult conditions. This research is a part of a larger demonstration effort using sensor technology to land in zero-zero weather at airfields that offer no or unreliable approach guidance. Several problems exist when landing without visual reference to the outside world. One is landing with a force greater than desired at touchdown and another is landing on a point of the runway other than desired. We compare different flare cueing systems to one another and against a baseline for completing this complex approach task.