10/31/2011. Remarks by Johan Visschedijk: "This aircraft was ordered in 1962 under contract 62-0019 as a P-3A-20-LO. It is pictured just before it was converted to an EP-3A (EATS) Extended Area Test System. Three P-3As (BuNo 150499, 150521 and 150522) were modified by Hayes International Corporation and Tracor at Mojave, California as EATS airborne instrumentation stations for use at the Pacific Missile Test Center, NAS Point Mugu, California, USA.

All ASW equipment was removed before installation of a Raytheon Rotman-lens phased array antenna in a distinctive extension of the vertical fin, also known as the "Billboard". In this photo the EP-3A carries extensive wool-tufting on the fin and antenna fairing to test airflow patterns. In 1994 the aircraft was redesignated NP-3D, on April 13, 2006 it went to the AMARC, and three months later, July 19, it was struck off charge."