The U.S. Air Force Air Mobility Command (AMC) is surveying the industry landscape to determine whether there are sources to supply thermal curtains to protect the crew of the Boeing [BA] KC-46A tanker from nuclear radiation.

“The cockpit thermal curtain protective system shall provide quick and positive protection to the aircrew members and their stations from the thermal radiation and luminous effects of nuclear weapon detonations,” per an AMC requirements document posted on March 18.

AMC said that it wants a company to supply about 140 sets of such thermal radiation shades. Each set is to consist of six cockpit and 14 fuselage shades “for all KC-46 aircraft windows,” AMC said.

The Air Force expects to field 179 KC-46As to replace its tanker fleet of more than 400 KC-135s and KC-10s.

Testing of the KC-46A to ensure the aircraft is protected from electomagnetic pulse (EMP) and radiation dates back to at least July 2017 when Boeing said it had eliminated EMP risk to the aircraft through testing at Naval Air Station (NAS) Patuxent River, Md., and at the Benefield Anechoic Facility at Edwards AFB, Calif.

That same year, however, the Pentagon Director of Operational Test & Evaluation (DOT&E) said that EMP testing “was not accomplished in accordance with the DOT&E-approved Test and Evaluation Master Plan (TEMP) and the LFT&E [Live Fire Test and Evaluation] Strategy.”

“While testing indicated the KC-46A flight-critical systems and boom refueling systems are likely survivable to the 6 decibel (dB) contractual requirement, the Program Office approved verification plan did not demonstrate the residual KC-46A mission systems capability during such an event,” DOT&E said in its annual fiscal 2017 report.

DOT&E said that “the program uninstalled or deactivated multiple mission critical systems prior to testing and, therefore, their EMP tolerance was not tested on an aircraft in a mission-representative configuration.”

“Additionally, the testing did not demonstrate the function of the AR [air refueling] boom and the wing AR pods following an EMP event to show the KC-46A can perform the required missions,” the report said.

In fiscal 2018, DOT&E said that the KC-46A program finished one test “to assess thermal curtains for crew survivability to nuclear threats against the KC-46A” and planned two more tests for fiscal 2019. In June 2019, the program finished thermal curtain materials qualification testing at Sandia National Laboratories, N.M., to permit the production of the thermal curtains, DOT&E said, adding that the Air Force and the Defense Threat Reduction Agency [DTRA] were planning to conduct testing of the KC-46A “against operationally realistic electromagnetic pulse effects.”

In fiscal 2020, the Air Force said it had finished analyses on the KC-46A’s “inherent nuclear hardness to blast, radiation, flash, thermal, and electromagnetic pulse effects and to assess base safe escape in the event of a nuclear attack” and had coordinated with DTRA to test the aircraft against operationally realistic EMP effects.

DOT&E said that the KC-46A program had finished continuous wave immersion electromagnetic pulse risk-reduction testing at Pease AFB, N.H., in November 2020 and passive system testing at NAS Patuxent River in August 2021, per a controlled unclassified information (CUI) version of the fiscal 2021 DOT&E annual report–a version obtained by Dan Grazier, the Jack Shanahan military fellow at POGO’s Center for Defense Information.

“The survivability of the KC-46A in a nuclear threat-induced environment cannot be determined without the active system test, scheduled to be completed in 3QFY22,” per DOT&E’s fiscal 2021 annual report. “Electromagnetic pulse testing to date indicates the shielding integrity of the aircraft is good with no obvious shielding gaps. In addition, maintenance of the aircraft does not degrade electromagnetic pulse hardness.”