GUY NORRIS / LOS ANGELES
Enhanced situational awareness and greater accuracy is to be available on Next Generation 737s in 2002
Boeing is developing flight display enhancements for the 717-200, Next Generation 737 and 777 to boost pilot situational awareness, and simplify navigation in terminal areas and on final approach.
Initial software is ready for loading into the common display system (CDS) and flight management system (FMS) of the Next Generation 737 fleet. Certification is planned for April 2002, with the capability expected to be available on production aircraft the following month, says Boeing.
Working with pilots and avionics vendors Honeywell and Smiths, Boeing has improved guidance cues on the primary flight display (PFD) to help in situations where extreme accuracy is needed, such as during the descent to intercept the instrument landing system. This will pave the way for more efficient approaches to congested airports such as San Francisco, Newark and Chicago-Midway.
"At the moment crews are flying approaches in a step-down mode, which is open to error," says Boeing. Although the FMS can already be programmed to fly a smooth trajectory, the pilots do not have the means to check this against required navigation performance (RNP) standards. A series of upgrades is being considered to enable pilots to monitor flight path accuracy, including lateral and vertical navigation (LNAV/VNAV) deviation scales, anticipation cues and actual navigation performance (ANP)/RNP bars.
The deviation scales and ANP/RNP bars have been developed to allow crews to keep within the RNP limits. These converge as the "funnel" of the approach path narrows during descent to landing. LNAV and VNAV deviation pointers are on the horizontal and vertical axis of the PFD, while a new glideslope "anticipation" cue is situated towards the top right hand corner. These can be provided for both types of flight instrument display layout - the navigation display format or the electronic flight instrument system/map display.
Another CDS PFD option planned for probable 2002 introduction includes a VNAV speed band indicator on the speed tape at the left hand side of the display.
Used with the new vertical situation display, the changes will provide the basis for a global positioning system landing display.
Source: Flight International
