Flying Complex Approaches Using a Head-up Display: Effects of Visibility and Display Type

Air traffic controllers, both civil and military, will soon have the ability to direct pilots to fly complex landing approaches. The imminent replacement of the Instrument Landing System (ILS) with a landing system based on Global Positioning System (GPS) technology at major airports in the United States will allow pilots to fly landing approaches with curved segments and varying descent rates in order to avoid noise abatement areas. From a military standpoint, flying complex approaches will allow better threat avoidance and operational security. Current head-up primary flight references may be inadequate to fly these complex approaches, but the proposed alternative – a pathway-in-the-sky and/or synthetic terrain display – may involve too much clutter for a head-up display (HUD), depending on visibility conditions. This paper reports the findings of an on-going program of research in the Air Force Research Laboratory designed to create a next-generation, head-up primary flight reference that will allow pilots to fly complex approach and weapon delivery paths regardless of visibility conditions. The findings of three studies examining different head-up display formats and external visibility conditions are summarized. The conclusions drawn from these studies are that a head-up pathway-in-the-sky display will greatly improve pilots’ ability to fly complex flight paths in comparison to the current military standard head-up display regardless of external visibility, and that the inclusion of synthetic terrain in the HUD will improve situation awareness in reduced visibility conditions.