4 days Ago By Luke Diaz
Updating the United States Air Force military's aerial refueling capability has focused heavily on the KC-46 Pegasus as it replaces the venerable KC-135 Stratotanker. Many point to the Pegasus as a transformative platform that can serve multiple functions. The KC-46 is based on the Boeing 767 airframe and brings a host of new technology to the aerial refueling (AR) mission along with being much more capable than just tanking, as its designation as a multi-role tanker transport (MRTT) indicates.
Analysts also scrutinize any shortfalls and mechanical concerns that have impacted the aircraft’s early track record. According to a recent Pentagon test director assessment, the KC-46 Pegasus tanker continues to have low mission capability and availability rates due to component shortages. There are still serious systemic issues with the program as well.
“The KC-46A is not meeting many of its suitability metrics,” according to the 2024 annual report from the office of the Director of Operational Test and Evaluation. At least 80% operational availability and 90% mission capability are required for the tanker, but the actuals “decreased throughout 2024,” the report noted. Growing pains The KC-46 had a mission-capable rate of 61% in 2024, which is worse than its 2023 readiness of 65%.
The KC-46 tanker's effective mission capable rate falls by an additional 24% on average when partially mission capable are factored in, such as those with a broken boom. The mission-capable/availability figures are derived from over 90,000 flight hours of maintenance data analyzed by the Joint Reliability and Maintainability Evaluation team. The Air Force Operational Test and Evaluation Center collected 15 times its originally required operational suitability flight test data as they have continued to track the program and work toward resolving ongoing issues.
The tanker can't progress to the next stage of testing until it receives updates to the refueling boom and the Remote Vision System, which are undergoing redesigns. AFOTEC has completed operational testing of the Wing Aerial Refueling Pod system and cooperative cyber testing of avionics systems. There are potential concerns with the WARPs under icing conditions, but the Air Force told DOT&E that it can use the existing system if needed and is pursuing a long-term solution.
There is also a weight and balance issue when the WARPs are installed, specifically when refueling both boom-type and drogue-type receiver aircraft. The Air Force continues to work with Boeing to develop critical upgrades to the refueling boom and RVS to support integrated testing in late FY25. The problems with the boom and RVS are well-known as Category 1 deficiencies, which could cause death or serious injury to personnel or severe damage to the weapon system.
The KC-46 is now able to refuel 26 of 27 possible aircraft, but with some restrictions that limit availability in certain environmental conditions and aircraft configurations. Software updates to the Radio Frequency Self Defense System are needed to improve the tanker's survivability, and flight testing of the RFSDS Version 6.0 is underway this quarter.
More testing will be needed to see if those updates are sufficient to protect the KC-46 in a contested environment. Pushing ahead The Air Force has worked around some of these problems, and the KC-46 is now able to refuel 26 of 27 platforms that it was designed to work with. Unfortunately, it is still facing several issues, including a fuel manifold system, cracks in the refueling receptacle drain line, and cracks in the auxiliary power unit drain mast.
One of the issues is a systemic failure of bleed air ducts, which has been upgraded to a Category 1 deficiency due to the number of aircraft affected and the number of repeat failures. Boeing and the Air Force are currently modeling and flight testing temporary procedures to alleviate the issue. “I’m 100 percent confident in its ability,” said General Mike Minihan , AMC’s commander.
“The people that fly, fix, and support it, love it. The people that refuel off of it, love it. The combatant commands .
.. are big fans of it.
And I’m happy that we’ve closed that [interim capability release] chapter out.” The KC-46 completed a Maximum Endurance Operation in June 2024, and Boeing is on contract for 158 of 179 planned KC-46s. As of late 2024, some 89 aircraft had been delivered, with the last contract awarded in November 2024.
Boeing has absorbed over $7.5 billion in losses on the program. The official recommendations from the Director, Operational Test & Evaluation DOT&E FY2024 Annual Report come in 3 points: “As recommended in the FY23 Annual Report, continue to pursue design changes necessary to close the remaining Category 1 deficiencies.
” “Develop and implement a strategy to address high drivers of availability and mission-capable rate shortfalls.” “Collect additional operational test data on the RFSDS during developmental testing of software updates and share with DOT&E to use for IOT&E reporting.” The KC-46A Pegasus is the Air Force's newest tanker and is based on the Boeing 767 airliner.
The price of innovation The numbers above may not sound good at first glance, but the KC-46 is leading the charge on the first technological and doctrinal evolution of the US Air Force’s aerial refueling fleet in decades. The stand-up of the new tanker has been far from flawless; however, the benefits that the new jet brings with it promise a huge boost in efficiency and mission performance. To put it in context, let’s review the readiness levels of some of the other USAF platforms.
Aircraft readiness in the USAF fleet has dropped to its lowest level in at least a decade and possibly 20 years, according to data provided to Air & Space Forces Magazine . The average mission-capable rate for all USAF fleets was 67.15% in fiscal 2024, down from 69.
92% in fiscal 2023 and 71.24% in fiscal 2022. These rates represent an average of all the fleets, with the most challenged fleets also being among the smallest in USAF's inventory.
The Air Force has changed its metrics of mission capability (MC) in recent years, including the availability of trained aircrew and maintenance personnel, spares, and other factors. MC rates ranged from a low of 30.45 for the CV-22 to 100% for the C-21 and MC-12.
Rates declined for 29 aircraft types and improved for 26 others, while the rest saw no change. Four fleets were at 100%: C-12, C-21, MC-12, and UV-18. The five worst-performing platforms of the non-trainer fleets were the CV-22 Osprey at 30% availability, the F-22A Raptor at 40%, EC-130H Compass Call at 42%, B-1B Lancer at 43% and the Sikorsky HH-60W Jolly Green II (Blackhawk rescue variant) at 46%.
The first tanker was propeller-driven and today they are based on airliners (the Boeing 707 and 767), but this is soon set to change. Bottom line A combined effort between the USAF leadership, Boeing developers, aircrew, and maintainers has been steadily improving the performance of the Pegasus as it goes through its teething phase. Innovative improvements like the APU Remote Start System (APURSS) came directly from the boots on the ground, airmen devising a remote system to speed up the KC-46’s launch cycle.
A KC-46 circumnavigated the globe in June of 2024 , returning to McConnell Air Force Base, Kansas, on July 1. The jet and its aircrew recorded a 45-hour nonstop flight around the world. The mission, called Project Magellan, saw the two crews aboard test their limits as they refueled Air Force jets around the globe along the way.
“Taking off from the [continental U.S.], refueling a C-17 over the Pacific and a combat sortie over Iraq, and coming back to support global strike aircraft showcases that we really can provide air refueling and support global reach anytime, anywhere,” said Colonel Brent Toth, aircraft commander and head of the 22nd Operations Group at McConnell.
At the end of the day, the Pegasus is far from a dud. It’s an excellent aircraft that brings more capability than ever before to one of the Air Force’s (and US Armed Forces) most important missions. It may not be perfect yet, but the KC-46 is well on its way to redefining the mission of airborne tankers in the world’s most powerful air force.
By the numbers Boeing's KC-46 tanker , built on its 767-200 series, was selected by the US Air Force in 2011 and has been in service since 2014. The company plans to phase out older KC-135 Stratotankers and some KC-10 Extenders in favor of a single platform by 2027. The KC-46 Pegasus can move heavier cargo loads than earlier tankers, making it suitable for more versatile mission sets.
Its capacity and ability to operate from smaller airfields make it suitable for dispersed operations. Boeing ensures that the new jet has a modular design, capable of iterative upgrades to support ongoing updates to ensure new software and hardware elements evolve with threats as they emerge. Primary Function: Aerial refueling and airlift Prime Contractor: The Boeing Company Power Plant: 2 Pratt & Whitney 4062 Thrust: 62,000 lbs.
(sea-level standard day) per engine Wingspan: 156 feet, 1 inch (47.5 meters) Length: 159 feet, 2 inches (48.5 meters) Height: 51 feet, 9 inches (15.
5 meters) Maximum Takeoff Weight: 415,000 pounds (188,240 kilograms) Fuel Capacity: 212,299 pounds (96,297 kilograms) Maximum Cargo Capacity: 65,000 pounds (29,484 kilograms), 58 passengers Pallet Positions: 18 pallet positions Air Crew: 15 permanent seats for aircrew, including aeromedical evacuation aircrew Aeromedical Evacuation Crew: Basic crew of five (two flight nurses, three medical technicians), adjustable as needed window.arrayOfEmbeds["jBvk3vQNUxc"] = {'youtube' : '""'}; window.arrayOfEmbedScripts["youtube"] = "null";.
