Figure 5-10. Ground-Based Augmentation System (GBAS).  Figure 5-11. NextGen improves airport surface movements, reduces  spacing and separation requirements, and better manages the  overall flows into and out of busy airports.  5-7 Head-Up Displays (HUD)  Benefits of NextGen  The implementation of NextGen will allow pilots and  dispatchers to select their own direct flightpaths, rather  than follow the existing Victor, Jet, and LF/MF airways.  Each aircraft will transmit and receive precise information  about the time at which it and others will cross key  points along their paths. Pilots and air traffic managers  on the ground will have the same precise information  transmitted via data communications.  Major demand and capacity imbalances will be worked  collaboratively between FAA air traffic managers and  flight operations. The increased scope, volume, and  widespread distribution of information by SWIM will  improve decision- making and let more civil aviation  authorities participate. The impact of weather on flight  operations will be reduced through the use of improved  information sharing, new technology to sense and  mitigate the impacts of the weather, and to improve  weather forecasts and decision-making. Better forecasts,  coupled with greater automation, will minimize airspace  limitations and traffic restrictions.  The new procedures of NextGen will improve airport  surface movements, reduce spacing and separation  requirements, and better manage the overall flows into  and out of busy airspace, as well as provide maximum use  of busy airports. [Figure 5-11] Targeting NextGen at the  whole of the NAS, rather than just the busiest airports,  will uncover untapped capacity across the whole system.  During busy traffic periods, NextGen will rely on aircraft to  fly precise routes into and out of many airports to increase  throughput. For more information on NextGen, visit www.  faa.gov/nextgen.  As aircraft became more sophisticated and electronic  instrument landing systems (ILS) were developed in the  1930s and 1940s, it was necessary while landing in poor  weather for one pilot to monitor the instruments to keep  the aircraft aligned with radio beams while the second pilot  divided time between monitoring the instruments and  the outside environment. The pilot monitoring reported  the runway environment in sight and the flying pilot  completed the approach visually. This is still the standard  practice used for passenger carrying aircraft in commercial  service while making ILS landings. As single-piloted aircraft  became more complex, it became very difficult for pilots  to focus on flying the aircraft while also monitoring a large  number of navigation, flight, and systems instruments. To  overcome this problem, the head-up display (HUD) was  GPS satellites  Ranging sources  Differential corrections, integrity data and path definition Omnidirectional VHF data broadcast (VDB) signal  GBAS reference receivers  GBAS ground facility  Status information 