Walt,

I congratulate you on all right answers and your most timely reply with welcome photos. You may have set a correct response time Quiz record. BRAVO ZULU to you!

In the early 1950s military aircraft manufacturers were able to spend company money bringing out new designs without any specific production contract. No

longer is that the case with military aircraft costs/defense budgets. The Ryan X-13 VERTIJET failed in small payload and short range, together with NO APPARENT military requirement. Of interest, the X-13 had a 1 thrust to weight ratio, necessary for vertical, accelerated flight.

Similar thing happened with the plethora of would-be commercial airliner manufacturers after Lindbergh's successful non-stop trans-Atlantic flight in 1927 from New York to Paris excited aviation world-wide. Some designs succeeded, some failed, while rapid technology such as the all-metal Douglas DC-2, a direct development of the sole DC-1, then the incredibly successful DC-3 blew away the contemporary competition. (Some 24 versions of the DC-3 were built, even in Russia as the Li-2).

Now, airlines customize specific requirements for the aircraft within weight and balance limits, for things like how many sections, such as First, Business and Coach or all Coach, etc, for passenger capacity via seat pitch, number of aisles, even makes/models of jet engines, as well as external paint color schemes, etc.

Same thing with military aircraft contracts. That is why we have three different F-35 LIGHTNING IIs- one version USAF, one version USN and a third STOVL version for the USMC.