»JDAM Design
~ JDAM requires MIL-STD-1553 data bus and MIL-STD-1760 digital interface.
~ JDAM is compatible with Navy Tactical Aircraft Mission Planning System (TAMPS) and
~ is planned to be compatible with Joint Mission Planning System (JMPS).

~ JDAM variants are built-up by installing Guidance Sets to MK 83, MK 84, BLU-109, BLU-110 or other bombs
~ along with required fuzing, sensors, initiators, and/or nose plugs/support cups
~ Guidance Sets are functionally same but are not interchangeable
~ because guidance software and physical interfaces are peculiar to each warhead type
~ Guidance Set physical differences correspond primarily to different warhead interfaces
~
Guidance Sets consists of:
~ tail assembly
~ aerosurfaces
~ umbilical cover
~ for KMU-558 only, a hardback, lug sleeves, suspension lugs, FZU Extender and SHOLS lugs

Each tail assembly consist of:
1 Tail fairing
2 Tail Actuator Subsystem (TAS)
3 Wire harness
4 Guidance Control Unit (GCU)
5 GPS antenna
6 Three moveable control fins
7 One fixed control fin
8 tail assembly has BIT capability which can be initiated both on and off aircraft by both maintenance and aircrew personnel
~ aircrew can perform BIT while aircraft is in flight
~ BIT and reprogramming are accomplished using AN/GYQ-79 Common Munitions Bit and Reprogramming Equipment (CMBRE)

1 Tail fairing:
~ forward structural member of tail assembly
~ mates to TAS at a faying surface using a radial screw/nut plate configuration
~ has a fuze access door to facilitate assembly/disassembly operations

2 Tail Actuator Subsystem TAS
~ aft tail assembly structure,
~ three electromechanical actuators to power three movable control fins,
~ a Lithium rmal Battery, and
~ associated controlling electronics
~ aft structure provides a mounting surface for GPS Antenna and mounting surfaces for control fins
~ actuators contain either electrically released motor brakes (used in KMU-55X/B Guidance Sets) or
~ a fin lock device (FLD) (used in KMU-55XA/B Guidance Sets) that unlocks tail control fins in flight
~ on Guidance Sets with KMU-55X/B designation, markings are applied to TAS to aid in determining proper fin positions
~ TAS marking applies to electrically released motor brakes only
~ when aft end of fins are within boundaries of alignment marks, fins are properly positioned for use
~ on Guidance Sets with KMU-55XA/B designation, control fins are secured with FLD
~ that uses retractable locking pins designed to eliminate fin movement during high speed, low altitude captive flight. TAS with FLD are not subject to captive carry flight restrictions. controlling electronics process digital commands into independent fin control movements, provide fin position feedback, battery initiation, brake unlock commands, and BIT status. TAS for KMU-556 and KMU-558 are physically identical;
~ however, they are not interchangeable due to differences in guidance software contained within GCU

3 Wire Harness
~ consists of MIL-STD 1760 umbilical connector, FMU-152/B fuze connector, GCU connectors, and a shielded wiring harness
~ a protective EMI cover is provided on umbilical connector
~ FMU-152/B fuze connector is connected to a stowage receptacle on inside surface of tail structure, when not in use

4 Guidance Control Unit (GCU):
~ consists of an integrated electronics assembly that includes Mission Computer, INS, GPS Receiver Module (GPSRM),
~ and other power conditioning electronics integrated into a common chassis
~ INS uses a Ring Laser Gyro (RLG) inertial measurement unit (IMU)
~ GCU is form factored to fit into tail assembly of both 2,000 lb. and 1,000 lb. guidance kits
~ Mission computer software implements autopilot, guidance and navigation functions
~ Guidance software uses an adaptive optimal guidance law
~ guidance law develops guidance commands based on weapon position and velocity state vector updates, target location, and desired impact parameters
~ guidance law continually computes optimal trajectory from current position to target to achieve an impact vector at planned impact point,
~ with planned impact angle and impact azimuth, at highest possible velocity
~ different Operational Flight Programs (OFP) are utilized for MK 84, BLU-109 and MK 83/BLU-110 variants
~ to account for different mass properties and aerodynamic characteristics

5 GPS Receiver Module (RM):
~ implements continuous P (Y) code tracking on L1 or L2 band for up to five satellites
~ a planned upgrade will incorporate a GPS receiver that can track all satellites in view
~ GPSRM software incorporates a fast acquisition mode that uses GPS position, velocity, time, and ephemeris data provided by aircraft
~ using this data, GPS receiver can achieve full position and velocity acquisition within 27 seconds and
~ full GPS navigation accuracy within 28 seconds after release
~ GPS antenna is located on aft end of TAS
~ antenna is connected to GCU by a cable that runs along exterior of tail assembly and is protected by a cover

Four control fins are attached to Tail Actuator Subsystem (TAS)
~ three of control fins are moveable, fourth control fin is fixed
~ aerosurfaces are fixed, mid body strakes that are attached to warhead using steel bands and T-bolts,
~ and in case of KMU-558, require a hardback
~ KMU-556 Strake Aerosurfaces consist of three formed steel “strakes” that are strapped around bomb body
~ upper strake is positioned over suspension lugs
~ right and Left strakes attach to slots in upper strake and are fastened around bomb with three metal straps that are tensioned with T-Bolt adjusting nuts
~ left and right strakes are fabricated in both stamped and riveted configurations that are interchangeable
~ strakes provide aerodynamic lifting surfaces around exterior of bomb body to enhance weapon maneuverability and range
~ KMU-558 Strakes/Hardback Aerosurfaces consist of right and left side formed steel “strakes”
~ that attach to hooks on hardback and strapped around bomb body
~ hardback is an aluminum casting that is positioned over a set of lug sleeves and attached with bolts
~ strakes attach to hooks that are hung from hardback and are fastened around bomb with two metal straps (primary configuration)
~ or three metal straps (alternate configuration)
~ straps are tensioned with T-Bolt adjusting nuts
~ strakes provide aerodynamic lift, maneuverability and other needed flight characteristics
~ hardback provides necessary physical interface to delivery aircraft
~ KMU-559 Strake Aerosurfaces consist of three formed steel “strakes” that are strapped around bomb body
~ upper strake is positioned over suspension lugs
~ right and left strakes attach to buckles on upper strake and are fastened around bomb with two metal straps that are tensioned with T-Bolt adjusting nuts
~ hardback is used in KMU-558 only. it provides necessary physical interface to delivery aircraft
~ it is an aluminum casting that is positioned over a set of lug sleeves and attached with bolts
~ because it adds a significant amount of additional space between bomb body and interface to delivery aircraft,
~ additional lug sleeves and suspension lugs are provided
~ additionally, a FZU Extender is provided for use when FMU-143E/B and FZU-32B/B configuration is built
~ FZU extender compensates for height of hardback and permits FZU-32B/B initiator to physically interface with bomb rack
~ umbilical cover is a formed steel part that attaches to tail assembly by inserting tab on aft end of cover into harness exit hole
~ forward end of umbilical cover is positioned and captured by a slot in upper strake
~ umbilical cover positions umbilical connector to mate correctly with delivery aircraft MIL-STD 1760 interface
~ and retains umbilical connector during separation
~ cover provides protection for wire harness during weapon handling operations
~ different umbilical covers are provided in KMU-556, KMU-558, and KMU-559 Guidance Sets
~ to accommodate physical differences in their respective warheads
~ SHOLS lugs are used in KMU-558 only
~ they are high strength steel parts that are installed under hardback assembly and
~ include interfacing features to attach SHOLS lifting trolleys with a single locking pin
~ SHOLS lugs provide pin attach points for rapid attachment of lift trolley assemblies to weapon
~ to facilitate weapon loading with SHOLS loading equipment

~ JDAM is compatible with existing FMU-139 and FMU-143 fuzes. It is also compatible with FMU-152/B JPF
~ JDAM tail assemblies are compatible with DSU-33B/B proximity sensor
~ DSU-33B/B provides general-purpose warheads with an air-burst capability
~ it can be used in GBU-31(V)2/B, GBU-32(V)2/B, and GBU-35(V)1/B configurations to provide an accurate air burst capability against appropriate targets
~ DSU-33B/B is not compatible with GBU-31(V)4/B. When DSU-33B/B is not used, a nose plug/support cup is used
~ A MK 122 Mod 0 arming switch can be used in any configuration. It is used in lieu of an initiator and its corresponding cable e. Initiators
~ when an arming switch is not used, either FZU-32B/B or FZU-48/B initiator and their corresponding cables can be used in GBU-31(V)2/B or GBU-31( V)4/B configurations
~ whenever DSU-33B/B is not used, a nose plug/support cup is used, either OGIVE or MXU-735