STRIKE EAGLE

AVIONICS

  

COCKPIT

Controlling the avionics is a crew of two who occupy a missionized cockpit optimized for the strike role and designed to ensure an efficient division of labor. The pilot is seated in the front while the Weapons System Operator (WSO) is seated directly behind the pilot under a single canopy. Both cockpits feature full flight controls.  The front cockpit primary instrumentation consists of a pair of programmable 6"x6" Kaiser monochrome (green) Multipurpose Displays (MPDs). Below the Up Front Controller and between the pilot's knees is a 5"x5" Sperry color MPCD. Each of these three MPDs can display a wide variety of weapons, aircraft, or navigational data as well as radar and FLIR images.  Standby instruments are featured on the instrument panel below the MPDs.

 

The rear cockpit features a row of four MPDs with two Sperry MPCDs on the ends and two Kaiser MPDs occupying the two inner positions.  The WSO cockpit also contains controls for the Strike Eagle's offensive and defensive electronic warfare systems. In addition to the normal flight controls, the WSO has separate hand-controllers on each side of the seat in order to more efficiently control the sensors and the displays. Like the stick and throttle, these two controllers are studded with switches and buttons so that the WSO does not have to look away from the displays to search for a particular control. The WSO station also has it's own UFC, but it is mounted off to the side under the right MPD.  

 

Most functions in both cockpits can be controlled by switches on the throttles and the control stick (referred to as “HOTAS” or Hands On Throttle And Stick). This allows the pilot to control the aircraft’s systems without having to remove his hands from the aircraft controls (a significant advantage in demanding phases of flight like a BFM engagement, flying low level at night, or an instrument approach in the weather).  Other cockpit avionics features include:

RADAR

One of the Strike Eagle's most valuable pieces of equipment is it's Hughes APG-70 pulse-doppler radar.  The  APG-70 is an improved version of the F-15C's APG-63 radar which retains all of the excellent capabilities of the APG-63 while at the same time featuring additional functions to aid in the precision strike role. The most notable feature of the APG-70 is its ability to produce photo-realistic patch maps of a given area down to the 8.5 foot (2.6 m) resolution. This resolution however can only be attained while within 10 nautical miles of the target. At greater distances the resolution diminishes to a maximum of 127 feet (38.7 m) at 160 nautical miles from the target. The quality of the HRM is also dependent on the "grazing angle" of the radar, the angle at which the radar beam strikes the surface that is to be mapped. The APG-70 has a minimum angle of 0.5 degrees which translates into an altitude of 1,000 feet for every 20 nm from the target. As a result, if the F-15E is performing a low-level ingress, the aircraft must increase altitude temporarily while the radar generates a HRM.  

 

LANTIRN

The LANTIRN (or Low-Altitude Navigation and Targeting, Infra-Red, for Night) system is made up of two separate pods, one mounted under each air-intake of the F-15E. One pod is primarily for low-level navigation in poor weather conditions while the other pod performs targeting roles. The AAQ-13 navigation pod under the right intake features a Texas Instruments terrain following radar which operates in the Ku band. Mounted inside the lower cylindrical pod of this two-level package, the antenna for the radar is located behind a small radome at the front of the unit. This radar has been coupled with the flight controls and throttle to provide a hands-off terrain-following course while maintaining a constant altitude down to a minimum of 200 feet. The Ku Band radar features five operating modes; normal, weather, LPI (Low Probability of Intercept) ECCM, and VLC (Very Low Clearance). Mounted on the front of the navigation pod is the Forward Looking Infra-Red (FLIR). Through a small window at the front of the unit, the FLIR provides the pilot with a 1:1 IR image of the world which is superimposed on the Heads Up Display (HUD), allowing the pilot see at night.

 

Beneath the left intake, the AAQ-14 targeting pod is made up of a separate attack FLIR and laser designator/range-finder housed inside of a small aerodynamic turret at the front of the cylindrical pod. Movement of the optics is provided by a nodding turret-head and rotating section of the pod, which work in conjunction with each other. Together, they provide the FLIR with a Field of Regard (FoR) measuring 150 degrees in any direction from its fully-forward position. The FLIR can be slaved to the radar or controlled separately by the crew in order to provide a view of the designated target. This FLIR offers several levels of magnification to allow for identification of targets from considerable distance. The laser designator/range-finder is correlated with the attack FLIR and can provide accurate ranges to designated objects. In addition, it is capable of sending specially-coded bursts of laser for the guidance of laser-guided bombs. The turret moves in relation to the target so that alignment of the sensor is independent of the aircraft's motion.  The value of the LANTIRN navigation and targeting pods is nearly $5 million.

 

INERTIAL NAVIGATION SYSTEM (INS)

The heart of the Strike Eagle's navigation suite is the Honeywell INS.  The Eagle's INS is the most sophisticated in the world of fighter aircraft, and gives the fighter complete autonomy in navigation. It needs no outside radio navigational aids to pinpoint it's real-time position in space.  The INS generates its inertial movement calculation from the Litton LN-94 (CN-1655/ASN) Ring Laser Gyro inertial navigation unit.  Three spools of fiber optic line carry two parallel laser beams over a long enough distance to allow measurement of changes in the frequency shift of the light as it accelerates or slows across three dimensions. Computers calculate the distance the jet has traveled since the INS was programmed with the coordinates of its ramp parking space before taxiing for takeoff.

After a sortie that covers 600 or 700 miles, the INS is usually no more than a half a mile out of register. Though not as accurate as a Global Positioning System, the independence from outside electronic jamming or other interference gives the F-15E a wartime capability that is unmatched.  The Strike Eagle is currently receiving the EGI, or Embedded GPS/INS system which allows real-time GPS updates to INS data. 

 

IFF

A Teledyne Electronics AN/APX-101 IFF transponder informs supplies Mode 3/C (data on the aircraft's range, azimuth, altitude, and identification) to air traffic controllers.  Ground radar stations and other suitably equipped aircraft can interrogate and tell that the F-15 is friendly.  A Hazeltine AN/APX-76 IFF interrogator checks the  IFF of other aircraft and informs the pilot if an aircraft seen on radar is friendly. A Litton reply evaluator for the IFF system operates with the AN/APX-76.

 

TEWS

The tactical electronic warfare system (TEWS) is an electronic warning/defense package designed to detect threats, classify them, and provide adequate protection against those threats.  It is an integrated sensors and countermeasures system where the radar, radar jammer, warning receiver and chaff/flare dispenser all work together to detect, identify and counter threats posed by an enemy. The TEWS also alerts the pilot to threats to the aircraft and administers countermeasures against those threats. The Loral AN/ALR-56C Radar Warning Receiver is made up of antennas located in the wingtips, at the end of the left vertical stabilizer, and a blade antenna located forward of the nosewheel bay. Upon detection, the Magnavox AN/ALQ-128 threat warning receiver system decides on the best countermeasure mix to use in order to counter the threat radar. Electronic countermeasures are delivered via the Northrop AN/ALQ-135 radar jammer through antennas located at the tip of the right vertical stabilizer and in fairings at the end of each tail-boom. Countermeasures can also be delivered by way of the Tracor AN/ALE-45 chaff/flare dispensers. 

 

The Strike Eagle’s TEWS can jam radar systems operating in high frequencies, such as radar used by short-range surface-to-air missiles, antiaircraft artillery and airborne threats. Current improvements to TEWS will enhance the aircraft’s ability to jam enemy radar systems. The addition of new hardware and software, known as Band 1.5, will round out the TEWS capability by jamming threats in mid-to-low frequencies, such as long-range radar systems

 

Source: Jane's All The World's Aircraft 2000

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