WAAS system

[k-robjoe]

I don´t have the time to have a cløser look at this now, so I´ll just post it here, and have a look tomorrow, for comments :

"A feature utilized by RNP approach procedures and utilizing the WAAS signal activated one year before September 11, 2001, is the use of descending constant radius turns, known as Radius-to-Fix (RF) turns.<17> Such turns are similar to the 330 degree descending right turn performed by American Airlines flight 77 (AA 77) upon its final approach-to-impact with the Pentagon building on September 11, 2001.<18> The point at which AA 77's 330 degree descending right turn terminated would be comparable to a Final Approach Fix (FAF), from where a straight final runway approach segment would commence."



The president of the "Naverus" company that now designs the RNP procedures that utilize technology available prior to September 11, 2001, described a complex RNP test flight performed by a Boeing 757 auto-pilot system, utilizing waypoint coordinate information contained within the aircraft's Flight Management Computer (FMC), that included a descent from a 38,000 foot altitude.<11>

"You're watching the whole thing unfold. The airplane is turning, going where it's supposed to go. ... it's all automatic."

"Watching the autopilot and flight controls work this airplane in these complex maneuvers was just fantastic. There was nobody in that airplane who wasn't visibly impressed."

By 1999, Boeing 757 and 767 aircraft like those involved in the terrorist attacks of September 11, 2001, contained digital flight control systems that can "automatically fly the airplanes on pre-selected routes, headings, speed or altitude maneuvers."<12>

http://www.911blogger.com/node/19305