C-135

The C-135 Modification Program is a critical line item within the Air Force's aircraft procurement budget, focused on sustaining and modernizing the C/KC-135 fleet to ensure its viability for global aerial refueling operations through 2050 and beyond. The C/KC-135 is the Air Force's only fully operational tanker and the oldest fleet by average age. It supports both active and reserve components for a range of missions including homeland defense, emergency response, and military support to civil authorities. The program's overarching objective is to address capability gaps, maintain compliance with security mandates, and resolve obsolescence issues through targeted modifications and upgrades.

One key objective is the KC-135 Block 45 modification, which enhances aircraft reliability and maintainability by upgrading avionics and flight control systems. This effort is necessary due to the aging nature of the fleet, with average aircraft age at 63 years and a designed service life extending to approximately 2053. Block 45 upgrades are implemented during scheduled Programmed Depot Maintenance (PDM) and are distributed across active duty, Air National Guard (ANG), and Air Force Reserve (AFR) aircraft. This ensures consistent capability improvements throughout the entire fleet.

The Rudder Position Indicator (RPI) program is a safety-critical modification, stemming from lessons learned after the Shell 77 accident. RPI installs cockpit displays showing actual and commanded rudder positions, improving aircrew situational awareness and reducing risk of dangerous errant rudder deflections. The program aims to modify hundreds of aircraft during PDM cycles, with funding allocated for procurement, support, and installation across all Air Force components.

The Real Time in the Cockpit (RTIC) initiative provides data connectivity for KC-135s, enabling interoperability with global and theater operations, intelligence, and tactical data networks. RTIC enhances battlespace awareness, mission safety, and combat support effectiveness by integrating advanced communications and data link capabilities. The program includes kit procurement, installation, and upgrades to ARC-210 radios in compliance with NSA cryptographic mandates, with milestones focused on completing installs and transitioning to newer radio generations.

MUOS Radios and COMM2 Crypto and Data programs address critical communications modernization. MUOS radios, installed in the COMM3 position, provide secure Beyond Line of Sight (BLOS) and Line of Sight (LOS) capabilities, ensuring compliance with NSA cryptographic modernization and mitigating obsolescence of ARC-210 Gen 3 radios. COMM2 Crypto and Data replaces legacy ARC-210 Gen 3 and VDL-2000 systems with ARC-210 Gen 6 and VHF-4000(E), delivering secure voice, anti-jam, and civil data link capabilities. These upgrades are essential for maintaining secure communications and supporting global operations, with procurement and installation scheduled for hundreds of aircraft.

The HF Modernization program is focused on replacing legacy ARC-190 radios with the ARC-260 system, enhancing secure, global voice and data connectivity, particularly in SATCOM-denied environments. This upgrade is vital for command and control (C2) communications and supports the secure exchange of classified information between Mobility Air Force aircraft and C2 agencies. The program covers hundreds of aircraft and includes interim contractor support, production representative unit deliveries, and integration milestones.

Additional objectives within the C-135 modification line include low-cost safety and capability improvements, such as VOR/ILS antennae upgrades, ADS-B installations, AERO-I SATCOM replacements, center console refreshes, vertical wipers, MAF connectivity, and hybrid SATCOM enhancements. These efforts collectively address diminishing manufacturing sources, regulatory compliance, and evolving operational requirements. This ensures the C/KC-135 fleet remains mission-ready and technologically relevant for decades to come.