The E-6B modification program was an effort to upgrade the E-6A aircraft and merge the Navy TACAMO with the Air Force ABNCCP missions. The E-6B is baselined on E-6A and the P-3 Update IV system. The CCU is made up of 6 CIM cards, 18 DAMs, 2 Power Conditioners, 8 Relay cards, 2 Control interface cards, 2 SIF cards and 2 microprocessors.

The system is comprised of:

• 1 CCU
• 9 CSUs
• 4 ACUs
• 1 CS/EAP
• 8 MSUs
• 1 MCU
• 10 EIU interfaces

The CSUs are identical to the E-6A CSUs with added switch settings for the ICS selector switch and 1 additional ISC (CT-II type CSU). The ACUs are identical to the E-6A units, The CS/EAP is also identical to the E-6A unit. The MSUs are also identical except for an additional switch for added nets. The MCU is an unmodified E-6A unit used for additional interface to the PA. The EIU interfaces are MIC & HDST interfaces (0 dBm) directly to the DAMs and are controlled exclusively via 1553.

Some features of E-6B are:

• 28 operator interfaces
• Simulcast
• Secure RX/TX indication
• 1553 RT interface
• Automatic degraded mode
• Fully redundant CCU operation
• 9 T/R radios, 3 assignable Cryptos, 3 Conference nets and 6 NAVAIDS
• Dual Lo-level HDST support
• Degraded/Backup operation
• Always WARMSTART (remember settings prior to power OFF)