*** Posted by Justin Haley ***
The XL is a cranked arrow delta winged f-16. This aircraft was built for a compition it lost to the f-15E in wich a strike aircraft was required. It lost not due to its performance, to the contrary, it was actualy superior in performance then the F-15E but mainly because Politics demanded MD kept its line running so that export Eagles could be sold. After this compatition was over the aircraft was bought by NASA for resurch. Since then many things have been done with the aircraft. It was tested with a linier flow wing. This incorperated very small holes in the wing tht did somthing to airflow that greatly reduced drag. This in turn meant that an f-16 even without an increase in engine power could theoreticaly go supersonic without afterburner. The cranked arrow delta wing is also an advance desing made to achieve the advantages of deltas, wich are mainly larger fuel load/ weapon load and instantanious turn rate while reducing the disadvantages of deltas. These are the bleeding off of energy in high speed turns where a delta will offer a great degree per second rate for the first few turns before the aircraft finds itself low on energy. A delta wing also has the advantage in the thin air enviorment of high altitude where a normal f-16 wing will make it strugle to keep up with the turn rate of such an aircraft as the XL. The XL is now in storage and is kept in flying condition so that any other tests can be conducted

[what is F16XL version and what for?]