USN and USMC F/A-18 fleet replacement squadrons and the Navy Fighter Weapons School (NFWS, also known as TOPGUN). They have also flown a number of USAF and NATO/Allied aircraft via the U.S. Navy's Personnel Exchange Program (PEP), to include, but not limited to, the USAF F-4 Phantom II, F-15E Strike Eagle and E-3 Sentry, the Royal Air Force Buccaneer S.2, Tornado GR1/GR1B/GR4/GR4A and Nimrod MR.2, and the Royal Canadian Air Force CP-140 Aurora. In all, the specific roles filled by an NFO can vary greatly depending on the type of aircraft and squadron to which an NFO is assigned. Past aircraft NFOs also flew in these retired aircraft, including as mission commander: EA-1F (formerly AD-5Q) Skyraider serving as electronic warfare officer/electronic countermeasures operator. A-3 (formerly A3D-1, A3D-2, A3D-2P, A3D-2Q and A3D-2T) Skywarrior (e.g., A-3B, EA-3B, ERA-3B, EKA-3B, TA-3B and VA-3B) serving as bombardier/navigator, navigator, electronic countermeasures/electronic warfare officer, and EWO signals evaluator. A-4 Skyhawk as students in the TA-4J, as TOPGUN adversary instructors in the TA-4F and TA-4J, as forward air controllers in the OA-4M (USMC only), and as electronic warfare officers in the EA-4F. A-5A (formerly A3J-1), A-5B (formerly A3J-2) and RA-5C (formerly A3J-3P) Vigilante serving as bombardier/navigator in the A-5A and A-5B and reconnaissance/attack navigator in the RA-5C. A-6 Intruder (e.g., A-6A, A-6B, A-6C, KA-6D, A-6E) serving as bombardier/navigator (USN + USMC). EA-6A Prowler serving as electronic countermeasures officer (USN + USMC). EA-6B Prowler serving as electronic countermeasures officer (USN + USMC). EA-7L Corsair II as electronic countermeasures officer. C-130F Hercules serving as navigator. EC-130Q Hercules "TACAMO" aircraft serving as navigator and airborne communications officer. LC-130 Hercules serving as navigator. E-1B (formerly WF-2) Tracer serving as radar intercept controllers. EC-121 (formerly WV-2 and WV-3) Warning Star as navigator and electronic warfare officer. EF-10 (formerly F3D-2Q) Skynight as electronic warfare officer (USMC only). F-4 (formerly F4H-1) Phantom II (e.g., F-4B, F-4J, F-4N, F-4S, EF-4B, EF-4J) serving as radar intercept officer (USN + USMC) EF-4B and EF-4J Phantom II serving as electronic warfare officer. RF-4B (formerly F4H-1P) Phantom II serving as reconnaissance systems officer (USMC only). F-14 Tomcat (e.g., F-14A, F-14B, F-14D) serving as radar intercept officer OV-10 Bronco (OV-10A, OV-10D, OV-10D+, OV-10G) serving as aerial observer and forward air controller (USMC only). SP-2E/H (formerly P2V-5 and P2V-7) Neptune (e.g., SP-2E, SP-2H, EP-2E, OP-2E, AP-2H, LP-2H) serving as tactical coordinator and navigator. SP-5B (formerly P5M) Marlin serving as tactical coordinator