EP-X
Boeing has started working on an unscheduled replacement aircraft, the EP-X, based on their 737.
On 16 August 2009, The Navy issued an "EP-X Analysis of Alternatives" that called for "information useful for the execution of the Electronic Patrol-X (EP-X) program which will recapitalize the EP-3E aircraft to provide tactical, theater, and national level Intelligence, Surveillance, Reconnaissance, and Targeting (ISR&T) support to Carrier Strike Groups and to Theater, Combatant, and National Commanders."
On 23 September 2009, leaked Navy budget documents for FY2011 revealed that the EP-X program would be delayed rather than started in that year.
On 1 February 2010, the President unveiled his proposed budget for 2010. This budget called for, among other things, cancelling the EP-X program.
Read more about this topic: Lockheed EP-3