For those interested in how LM was able to win the JSF program, please look at the history of the Advanced Short Take-Off/Vertical Landing (ASTOVL) program.
McDonnell –Douglas had the top two (ASTOVL) proposals (one for gas-coupled lift fan and one for shaft-coupled lift fan). DARPA told McDonnell to move forward with the gas-coupled lift fan using the GE YF120 engine (which later was developed into the General Electric/Rolls-Royce F136). DARPA then funded LM to work on the shaft-coupled design using the P&W F119 engine (which was developed into the P&W F136). McDonnell actually built a full-scale design to house and test a gas-coupled lift fan when the program was terminated and the JSF program was started.
While McDonnell was developing its proposal for the JSF program, it was told that the decision had been made to use the P&W engine and that McDonnell would have to include the cost of developing the GE YF120 engine into their program cost estimate. At that point there was little time to do anything except bring Northrop on board with a separate lift engine.
So that is also the story of how DARPA eventually caused the demise of McDonnell Douglas, forcing it to merge with Boeing.
(Sorry Courtney, but since it was brought up…..)