The U.S. Air Force is seeking industry input on a possible replacement of the fuel management and flight display systems for 276 of the service’s more than 400 KC-135 Boeing [BA] Stratotankers, first fielded in 1958. The replacements–including a new multifunction display system–would come under the KC-135 Center Console Refresh (CCR) program.

In 2015, the Air Force awarded Rockwell Collins–now Collins Aerospace–a nearly $306 million contract to upgrade the KC-135 fleet to the Block 45 configuration with digital avionics and new radio altimeter, autopilot, and digital fight director systems–work to be conducted at Tinker AFB, Okla. Before that, between 1997 and 2002, the Air Force had modernized the KC-135 under the Pacer CRAG (compass, radar and GPS) program.

The Air Force KC-135 program office at Tinker AFB and the Air Force Life Cycle Management Center (AFLCMC) were to hold a virtual CCR industry day on May 10-11 during which the Air Force was to discuss CCR and engage in one-on-one sessions with representatives from L3Harris [LHX], Northrop Grumman [NOC], Collins Aerospace, Honeywell Aerospace [HON], BAE Systems, IAI North America, Moog, Inc., Universal Avionics, Field Aerospace, and Groundspeed Ops.

“Five components within the fuel management system and flight display systems are facing obsolescence in the near future,” per an AFLCMC briefing from the CCR industry day. “These components include integrated fuel management panel; fuel management advisory computer; control display units; tank interface unit; multi-functional displays.”

AFLCMC said that beyond replacing the KC-135 flight management and flight display systems, the goal is “to improve these systems to enable better performance, supportability and future growth to allow continued KC-135 operations beyond 2040.”

The CCR program is part of a four-pronged Air Force effort to provide beyond line of sight and line of sight secure voice and command and control with new cryptographic algorithms being developed under the VINSON/ANDVT Crypto Modernization (VACM) program. Beside CCR, the communications modernization includes integration of mobile user objective system (MUOS) radios on Block 45 KC-145s to replace Collins Aerospace ARC-210 Generation 3 radios, which the Air Force said will be obsolete by next year; a new high frequency radio to allow the KC-135s to operate in scenarios in which satellite communications are jammed; and cryptographic upgrades required by the National Security Agency.

In fiscal 2023, the Air Force is seeking congressional authorization to retire six KC-135s and 10 KC-10s. In addition, the service plans to field 24 Boeing KC-46A Pegasus tankers in fiscal 2023. The KC-46A has faced a number of technical problems, including with the tanker’s Remote Vision System (RVS).

The end of KC-46A initial operational test and evaluation (IOT&E) and a full-rate production decision are not expected until fiscal 2024 because of problems with the aircraft’s RVS and the refueling boom’s actuator (Defense Daily, March 31).

The Controlled Unclassified Information (CUI) version of the Pentagon Director of Operational Test and Evaluation’s fiscal 2021 report also said that the KC-46A Pegasus “is vulnerable in a cyber-contested environment” and that specific vulnerabilities and their effect on the KC-46A mission will be available in the classified initial operational test and evaluation (IOT&E) report annex. IOT&E for the KC-46A began in May 2019.

The Air Force is to field 179 KC-46As by 2029 to replace the KC-135s and KC-10s. At that time, the Air Force tanker fleet would consist of the 179 KC-46As and some 300 remaining KC-135s.