Development of a real-time aeroperformance analysis technique for the X-29A advanced technology demonstrator

The X-29A advanced technology demonstrator has shown the p r a c t i c a l i t y and advantages o f the c a p a b i l i t y t o compute and display, i n rea l time, aeroperformance f l i g h t resu l ts . This c a p a b i l i t y includes the ca l cu la t i on o f the i n f l i g h t measured drag polar, l i f t curve, and a i r c r a f t s p e c i f i c excess power. From these elements, many o ther types o f aeroperformance measurements can be computed and analyzed. The technique can be used t o g ive an inanediate postmaneuver assessment o f data quali t y and maneuver technique, thus increasing the p r o d u c t i v i t y o f a f l i g h t program. A key element o f t h i s new method was the concurrent development o f a realt ime i n f l i g h t net t h r u s t algori thm, based on the s i m p l i f i e d gross t h r u s t method. ne t t h r u s t a lgor i thm al lows f o r the d i r e c t calcul a t i o n o f t o t a l a i r c r a f t dray. This