The F-15E's deep strike mission is a radical departure from the original intent of the F-15, since the F-15 was designed as an air superiority fighter under the mantra "not a pound for air-to-ground." The basic airframe, however, proved versatile enough to produce a very capable strike fighter. The F-15E, while designed for ground attack, retains the air-to-air lethality of the F-15, and can defend itself against enemy aircraft. The F-15E prototype was a modification of the two-seat F-15B. The F-15E, despite its origins, includes significant structural changes and much more powerful engines. The aft fuselage was designed to incorporate the more powerful engines with advanced engine bay structures and doors. The advanced structures utilized Superplastic forming and diffusion bonding (SPF/DB) technologies. The back seat is equipped for a Weapon Systems Officer (WSO pronounced 'wizzo') to work the new air-to-ground avionics. The WSO uses multiple screens to display information from the radar, electronic warfare, or Thermographic cameras, monitor aircraft or weapons status and possible threats, select targets, and use an electronic moving map to navigate. Two hand controls are used to select new displays and to refine targeting information. Displays can be moved from one screen to another, chosen from a menu of display options. Unlike earlier two-place jets (e.g. the F-14 Tomcat and Navy variants of the F-4), whose back seat lacked flying controls, the back seat of the F-15E cockpit is equipped with its own stick and throttle so the WSO can take over flying, albeit with reduced visibility.
To extend its range, the F-15E is fitted with two conformal fuel tanks (CFTs) that hug the fuselage. These produce lower drag than conventional underwing/underbelly drop tanks. They carry 750 U.S. gallons (2,800 liters) of fuel, and house six weapons hardpoints in two rows of three in tandem. Unlike conventional drop tanks, CFTs cannot be jettisoned, thus the increased range is offset by the degraded performance from the increased drag and weight compared to a "clean" configuration. Similar tanks can be mounted on the F-15C/D and export variants, and the Israeli Air Force makes use of this option on their fighter-variant F-15s as well as their F-15I variant of the Strike Eagle, but the F-15E is the only U.S. variant to be routinely fitted with CFTs. The Strike Eagle's tactical electronic warfare system (TEWS) integrates all countermeasures on the craft: radar warning receivers (RWR), radar jammer, radar, and chaff/flare dispensers are all tied to the TEWS to provide comprehensive defense against detection and tracking. This system includes an externally mounted ALQ-131 ECM pod which is carried on the centerline pylon when required. The APG-70 radar system allows air crews to detect ground targets from longer ranges. One feature of this system is that after a sweep of a target area, the crew freezes the air-to-ground map then goes back into air-to-air mode to clear for air threats. During the air-to-surface weapon delivery, the pilot is capable of detecting, targeting and engaging air-to-air targets while the WSO designates the ground target. The APG-70 is to be replaced by the AN/APG-82(v)1 active electronically scanned array Radar (AESA) radar, which will begin flight tests in January 2010 with initial operational capability expected in 2014. Its inertial navigation system uses a laser gyroscope to continuously monitor the aircraft's position and provide information to the central computer and other systems, including a digital moving map in both cockpits. The low-altitude navigation and targeting infrared for night (LANTIRN) system is mounted externally under the engine intakes; it allows the aircraft to fly at low altitudes, at night and in any weather conditions, to attack ground targets with a variety of precision-guided and unguided weapons. The LANTIRN system gives the F-15E exceptional accuracy in weapons delivery day or night and in poor weather, and consists of two pods attached to the exterior of the aircraft. At night, the video picture from the LANTIRN can be projected on the HUD, producing an infrared image of ground contour.
The navigation pod contains a terrain-following radar which allows the pilot to safely fly at a very low altitude following cues displayed on a heads up display. This system also can be coupled to the aircraft's autopilot to provide "hands off" terrain-following capability. Additionally, the pod contains a forward looking infrared system which is projected on the pilot's HUD which is used during nighttime or low visibility operations. The AN/AAQ-13 Nav Pod is installed beneath the right engine intake.
The targeting pod contains a laser designator and a tracking system that mark an enemy for destruction as far away as 10 mi (16 km). Once tracking has been started, targeting information is automatically handed off to infrared homing air-to-surface missiles or laser-guided bombs. The targeting pod is mounted beneath the left engine intake; configurations may be either the AN/AAQ-14 Target Pod, AN/AAQ-28 LITENING Target Pod or the AN/AAQ-33 Sniper Advanced Targeting Pod. The F-15E carries most weapons in the USAF inventory. It is also armed with AIM-9 Sidewinders and AIM-120 AMRAAMs. Since the Strike Eagle retains the counter-air capabilities from its Eagle lineage, it is regularly trained for counter-air missions, and fully capable for Offensive-Counter-Air. Like the F-15C, the Strike Eagle also carries an internally mounted General Electric M61A1 20 mm cannon with 650 rounds, which is effective against enemy aircraft and "soft" ground targets. The MIDS Fighter Data Link Terminal, produced by BAE Systems, improves situational awareness and communications capabilities via the Link16 datalink. Since 2004, South Korean firm LIG Nex1 has been manufacturing the F-15's Head-up display; a total number of 150 HUDs were delivered by 2011. LIG Nex1 had been a participant in the F-15K program as a subcontractor to Rockwell Collins. LIG Nex1 is also preparing to manufacture F-15's new multi-function display and flight control computer. Also since 2004, Korea Aerospace Industries (KAI) has produced the wings and forward fuselages of the F-15; in 2008, KAI established another production line for Singapore's F-15SG. KAI is involved in the development and manufacture of the Conformal Weapons Bay (CWB) to be used on the F-15 Silent Eagle.