Not every experimental jet fighter made by the U.S. military would go on to reach production, for any number of reasons.

Lockheed Martin's F-35 Lightning II hit full-rate production last year. Today, over 150 fighter jets are being made annually.

The fighter jet could go into production as early as this year upon acceptance of a production offer from the Indian government, a spokesperson for the Russian state arms exporter Rosoboronexport ...