The 66-Year-Old KC-135 That Flew Its Final Mission In December, Then Got Pulled Back Out Of The Boneyard

Published Sep 11, 2026, 11:00 AM EDT Chris earned a Master’s degree in Defense and Strategic Studies (Highest Honors) from the University of Texas at El Paso. His graduate work concentrated on Global and National Security, Low-Intensity Conflict, Modern Warfare, and US grand strategy. He also undertook extensive regional studies, analyzing how key regions integrate into the broader US security architecture. This rigorous program provided him with a comprehensive understanding of U.S. military operations, global strategy, and weapons systems. Additionally, he gained a strong appreciation for great power competition.—an increasingly central force shaping international relations and conflict for the foreseeable future. Sign in to your Simple Flying account Aerial refueling is one of the central components of the United States' ability to project power globally. At the heart of this is the Air Force's (USAF) fleet of aerial refueling tankers. These aircraft make it possible for Air Mobility Command to rapidly move military personnel anywhere in the world within hours and sustain them once an operation has commenced. The heart of the USAF's refueling fleet since August 1956 has been the reliable and rugged Boeing KC-135, of which 820 entered service. For the last 70 years, these aircraft have seen the United States through the Cold War, post-Cold War peacekeeping and humanitarian operations, wars in Iraq and Afghanistan, and most recently, operations over Iran. While this fleet has been undergoing a phased retirement with the arrival of the Boeing KC-46 Pegasus, the KC-135 remains a reliable aircraft during this transition. This was put on display during Operation Epic Fury, when at least one KC-135 nicknamed "Ethel" was pulled out of retirement amid the increased demands placed on the tanker fleet, highlighting the continued importance of the Stratotanker as it transitions to the Pegasus. Operation Epic Fury & Ethel's Final Sacrifice Credit: US Air Force Operation Epic Fury, the devastating air campaign launched by the US and Israel with the goal of demolishing Iran's nuclear infrastructure and its desire to become a regional nuclear power, was launched on February 28 at 1:15 AM and officially concluded on May 5. According to US Central Command, the operation used 26 types of aircraft, including fighters, electronic warfare and reconnaissance aircraft, heavy-lifters, drones and one of the largest concentrations of bombers seen in recent decades. The latter included the forward deployment of 15 B-1Bs and six B-52Hs. This wide array of aircraft was deployed from several locations across the United Kingdom, Europe and the Middle East and coordinated to hit in excess of 13,000 targets. This intensive air campaign required a significant contribution from the KC-135 fleet, which performed hundreds of connections in order to keep the air operation moving apace. While the USAF operates and maintains around three-quarters of the world's refueling fleet, its tanker force includes 374 KC-135s and 105 KC-46As. However, not all of these tankers are available for deployment at the same time. Some are undergoing maintenance or modernization, while others are supporting operations under different global commands and were therefore unavailable for deployment in support of Epic Fury. Further, as reported by Aeronautics Magazine, the operation resulted in the loss or destruction of at least 42 US aircraft, placing additional pressure on the USAF's available refueling fleet. Aircraft General Characteristics: KC-135 Stratotanker Related Data Prime Contractor The Boeing Company Power Plant KC-135R/T, Four CFM-International CFM-56 turbofan engines KC-135E, Four Pratt and Whitney TF-33-PW-102 turbofan engines Thrust KC-135R, 21,634 pounds (9,814 kg) each engine KC-135E, 18,000 pounds (8,165 kg) each engine Wingspan 130 feet, 10 inches (39.88 meters) Length 136 feet, 3 inches (41.53 meters) Height 41 feet, 8 inches (12.7 meters) Speed 530 miles per hour at 30,000 feet (9,144 meters) Ceiling 50,000 feet (15,240 meters) Range 1,500 miles (2,419 kilometers) with 150,000 pounds (68,039 kilograms) of transfer fuel; ferry mission, up to 11,015 miles (17,766 kilometers) Maximum Takeoff Weight 322,500 pounds (146,285 kilograms) Maximum Transfer Fuel Load 200,000 pounds (90,719 kilograms) Maximum Cargo Capability 83,000 pounds (37,648 kilograms) Included in the above figure were seven Stratotankers, one of which was lost in a deadly mid-air collision over western Iraq, while another incurred significant damage. The remaining five were destroyed while parked during a coordinated Iranian missile and drone strike on Prince Sultan Air Base in Saudi Arabia. The sudden gap created by the attacks and collision forced the USAF to take drastic measures. The elderly tanker that returned to service was nicknamed "Ethel" (tail number 58-0011) and made its final flight to Davis-Monthan Air Force Base, Arizona, known as the "Boneyard," on December 19, 2025. Just four months later, it was recalled in the first week of April. However, the tale takes a somewhat less glorious turn. Ethel was reactivated and flown from the Boneyard to the Oklahoma City Air Logistics Complex at Tinker Air Force Base in order to provide much-needed parts for the active-duty, battle-damaged KC-135s. By the end of her lifecycle, Ethel had amassed 41,000 logged flying hours, served as a nuclear command and control aircraft in the 1960s, likely served in all major US combat operations through the 21st century, and had been flown or maintained by generations of pilots and airmen. A Future Without The KC-135 And Its Replacement Credit: US Air Force The last 70 years of aerial refueling have been dominated by the KC-135; this aircraft has been a cornerstone of American power projection, and that era is now coming to a close. Nowhere is this more evident than at McConnell Air Force Base, which has hosted the Stratotanker since 1971. Recently, the base's 22nd Air Refueling Wing (ARW), 22nd Operations Group, 350th Air Refueling Squadron and 722nd Aircraft Maintenance Squadron have witnessed the final departure of numerous Stratotankers and the arrival of more KC-46 Pegasuses. Regarding this transition, Colonel Joe Wall (USAF), commander of the 22nd ARW, stated, “Our Airmen are pivoting to sustain the remaining KC-135 fleet, pursuing new opportunities or stepping up to lead the KC-46 enterprise. It’s a massive realignment of talent, tools and equipment to build our future.” The Stratotankers stationed at McConnell are being gradually reassigned to other bases as the airfield takes on an ever greater number of Pegasuses. In early April, the 25th KC-46 arrived at McConnell and will gradually displace the remaining Stratotankers, eventually becoming the only refueling aircraft operating from the airbase and making McConnell the largest KC-46 operating location in the USAF. The conversion to an all-Pegasus fleet began in the early 2010s. At that time, contractors under the oversight of the US Army Corps of Engineers Kansas District constructed three new KC-46 maintenance hangars, technical training dormitories, an air traffic control tower, and other related facilities. With work completed, the base received its first two Pegasuses in January 2019. Presently, the USAF has received 105 KC-46s from Boeing, while the planned fleet is expected to consist of approximately 263. As the future of the USAF's refueling fleet, the Pegasus can refuel fixed-wing aircraft using either its boom or hose-and-drogue systems. The tanker is equipped with a modernized KC-10 refueling boom that is operated via a fly-by-wire control system. The refueler also features two underwing hose-and-drogue pods, allowing it to refuel multiple aircraft at once. For cargo transport, the Pegasus can carry up to 18 463L cargo pallets, and its fuselage can accommodate 58 passengers in its normal configuration and 114 for contingency operations. For aeromedical evacuations, the KC-46 can be reconfigured to safely transfer 58 patients (24 litters / 34 ambulatory). Aerial Refueling And Power Projection The USAF's refueling fleet, in addition to its large network of bases, allows the US to project military power anywhere on the planet within a few hours. Tankers allow combat and large transport aircraft to remain airborne until they reach their destinations, whether a combat zone or an area in need of humanitarian assistance. Without such a force of refueling aircraft, any operation would depend on the USAF's bases for refueling. This would add hours to any time-sensitive mission because aircraft would need to land, taxi, wait for ground personnel to service them, and then take off again. In combat operations, opportunities would be lost, and deployed military personnel may lack air support and the supplies needed to be effective in battle. A clear example is the "tanker bridge" across the Atlantic, which enabled the US military to rapidly transfer personnel, equipment, and other vital combat-sustaining materials into Iraq. The primary air bridge was supported by the Maine and New Hampshire Air National Guard, which operated the Northeast Tanker Task Force, allowing Air Mobility Command to directly deliver to the theater. By the time the bridge mission concluded, on September 11, 2003, "...the Northeast Tanker Task Force alone had flown over 1,700 sorties and offloaded more than 130 million pounds of fuel." The air bridge was a key enabler that allowed commanders to maintain sensitive timetables and support the ground force. A New Era Of American Aerial Refueling Credit: US Air Force The KC-135 has supported American power projection for seven decades, becoming one of the most important aircraft in the history of US airpower. However, Operation Epic Fury demonstrated that despite its age, the Stratotanker remains indispensable to sustaining large-scale, long-range air operations. The emergency return of Ethel from retirement further illustrates how valuable the aging fleet remains when the USAF's tanker capacity is under significant strain. The KC-46 Pegasus is now assuming an increasingly important role in this mission, bringing greater fuel capacity, versatility, and modern capabilities to the aerial refueling fleet. As more KC-46s enter service and the remaining KC-135s are gradually retired or reassigned, the USAF is entering a new era of aerial refueling. Yet the legacy of the Stratotanker will not disappear overnight, as its decades of service continue to underpin the transition to America's next-generation refueling force.