According to Defense News, the decision was made after a recent occurrence where the cargo locks on the bottom floor of the tanker became unlocked during flight. This raised significant concerns that the cargo could become unsecured mid-flight and hurt or kill airmen or even cause damage to the aircraft itself.
In a statement released by Air Mobility Command spokesperson, Col. Damien Pickart, the US Air Force endorsed, “ As a result of this discovery, the Air Force has submitted a Category 1 Deficiency Report and is working with Boeing to identify a solution […] Until we find a viable solution with Boeing to remedy this problem, we can’t jeopardize the safety of this aircrew or aircraft.” Category 1 is defined as “serious technical issues that could said aircrew and aircraft."
DN goes on to report that if the restraints on the bottom of the plane floor, meant to hold pallets or cargo in place become undone, it wouldn’t just pose a safety risk to the crew, but the plane itself could become unbalanced, which makes the craft “difficult, if not impossible to control.”
Boeing has confirmed the issue in a statement of their own. “The company and the Air Force are cooperatively analyzing the locks to determine to determine a root cause. The safety of the KC-46 aircraft and crew is our top priority. Once the cause has been identified, the tanker team will implement any required actions as quickly as possible.”
Besides this Category 1 deficiency, three others have been identified, as it relates to the boom of the aircraft, which allows for refueling of other craft while in flight.
1) Boeing is being compelled to design a new boom to accommodate refueling certain craft.
2) The remote vision system which allows the boom operates to steer the boom, provides misleading imagery in certain lighting
3) The boom, likely due to the problems with the viewing system, scrapes the body of the crafts it iss trying to couple with to refuel.
The KC-46 program has been besieged by blunders since deliveries began rolling into the Air Force. Most notably, the Air Force began refusing acceptance of delivery of the planes after Boeing employee trash and industrial tools were discovered within the body of the tanker. At that time, Air Force officials then visited the Everett plant, where they were assembled.
Image courtesy of Boeing KC-46A gallery.