Growing focus on the versatility of mid-air refuellers in the Indo-Pacific
The utility of tanker aircraft as a vital force multiplier for air forces has been demonstrated time and again. From moving shorter-ranged aircraft across long distances or keeping them in the air for longer and thus increasing their time on station, today’s tankers are also designed from the outset to act as transport aircraft, capable of ferrying passengers and/or cargo without needing any modification while still being able to refuel other aircraft at the same time.
Indo-Pacific nations are increasingly coming around to this fact, with more introducing tankers into their inventories or planning to. These have ranged from high-end tankers in the form of the Airbus A330 Multi-Role Tanker Transport (MRTT) and Boeing KC-46 Pegasus, to the relatively simple expedient of adding refuelling pods to airlifters such as the Airbus A400M or Lockheed C-130 Hercules.
AIRBUS A330/KC-30A MRTT
The Airbus A330 Multi-Role Tanker Transport (MRTT) has found a willing market in the Indo-Pacific with a number of nations already operating the type which is also in the running for the requirements of several other regional countries.
As its name suggests, the A330 MRTT is based on the Airbus A330-200 airliner, converted to a tanker with the addition of a fly-by-wire Aerial Refuelling Boom System (ARBS) or a hose drogue unit in its rear fuselage, and two outer wing refuelling pods.
The A330 MRTT can carry 111 tons of fuel in its inbuilt fuel tanks, with offload capacity being whatever is left over after taking away what the aircraft needs to get to its assigned refuelling track, stay on station and return to base (plus reserve).
The spacious cabin can carry in excess of 250 passengers, and 37 tonnes of containerised cargo in its vast underfloor cargo hold.
Australia became the first operator to take delivery of an MRTT when, after a protracted development, the third aircraft of an initial five on order – A39-003 – was handed over to the RAAF in 2011, three years behind the original plan.
The first of the initial five RAAF MRTTs was converted to tanker configuration at Airbus in Getafe, with the remainder having their conversion work done at Qantas Defence Services in Australia.
Known as the KC-30A in Australian service, the MRTT was selected in 2005 to replace the RAAF’s remaining Boeing 707 tankers. The aircraft’s development was originally limited by the need to remediate issues with the ARBS, with aircraft 001 staying behind at Airbus in Spain to continue work on the remediation program, and the RAAF instead focusing initially on developing its capability to refuel probe-equipped aircraft.
In 2015 the boom was cleared for use and, since then, the KC-30A has been cleared for refuelling a whole host of receivers using boom and hose and drogue methods, ranging from western types such as the Lockheed-Martin F-16 and F-35, the Boeing F/A-18 classic and Super Hornets, C-17A Globemaster III, E-7A Wedgetail, Dassault Rafale, and even Russian types such as the Indian Air Force’s (IAF) Sukhoi Su-30MKI.
Assigned to 33SQN based at Amberley near Brisbane, the RAAF has also used its KC-30A on operations. Along with Super Hornets and an E-7A, a KC-30A was deployed to the UAE between 2014 and 2020 as part of the ADF’s Operation OKRA Joint Task Group to support the Operation Inherent Resolve air campaign against the Islamic State over Iraq and Syria. It built up an impressive reputation as a stable and reliable platform, and was anecdotally called the “tanker of choice” of the coalition.
More recently, a KC-30A flew eight missions to support the operation to evacuate international citizens and Afghans from Kabul as the Taliban retook that country, and ferried refugees from the UAE to Australia.
After the initial five aircraft, Australia has taken an additional two KC-30As. In 2015 former Defence Minister Kevin Andrews announced the acquisition of two former Qantas/Jetstar airliners as these were closest in series production and configuration to the initial five KC-30As. One of these has been equipped with a “modest” VIP fit that includes seating, meeting spaces, and communication facilities so it can support overseas Prime Ministerial missions.
Other regional operators of the MRTT are Singapore and South Korea, with six and four aircraft in service respectively.
Singapore ordered the MRTT in 2014 to replace its fleet of four KC-135Rs that it acquired in the late 1990s. The KC-135Rs were all former USAF KC-135As that had been stored at the desert boneyard in Arizona and refurbished and upgraded with new engines and a glass cockpit.
Singapore had previously operated four KC-130B Hercules fitted with refuelling pods to refuel its fleet of probe-equipped McDonnell-Douglas A-4 Skyhawk and Northrop F-5 Tiger II fighters, but needed a boom-equipped aircraft to support its then-new Lockheed-Martin F-16 fighters.
The Republic of Singapore Air Force (RSAF) has also embraced efforts by Airbus to incorporate new technology onto the MRTT, signing up to become the first customer of the Automatic Air-to-Air Refuelling (A3R) capability and providing one of its aircraft for development, trials, and certification work on the A3R-equipped boom.
The RSAF had also previously been involved with the development of boom flight control laws for the Boeing F-15 via Singapore’s Defence Science and Technology Agency (DSTA). An earlier trial with an RAAF MRTT and USAF F-15s in 2015 found that there were adverse aerodynamic effects during certain flight regimes, necessitating the development of the new flight control laws for the MRTT to safely refuel the F-15 when Singapore took delivery of its first aircraft.
BOEING KC-46A PEGASUS
Unlike Australia and South Korea, Japan went with the US decision to acquire the Boeing KC-46A Pegasus as its next generation tanker. Based on the Boeing 767-2C freighter, the KC-46A was a natural choice for Japan, given that the Japan Air-Self Defense Force is already operating the earlier KC-767 as its in-service tanker, four of which entered service in 2008.
The KC-767s are currently assigned to the JASDF’s 404 Hikotai at Komaki Airbase in Nagoya. Japan was a late entrant to the adoption of mid-air refuelling, with previous governments viewing the capability as too offensive in light of its pacifist constitution that limits it to purely defensive weapons.
Japan selected the KC-46A in October 2015 after an evaluation in which Airbus refused to take part after it felt the country’s requirements were slanted towards the KC-46. The FMS request for three tankers was approved by the State Department in September 2016, with the contract for the first awarded to Boeing in December 2017.
The KC-46 can transfer just over 94 tonnes of fuel via its fly-by-wire boom and a pair of refuelling pods on its outer wings. The type controversially won the US Air Force’s KC-X program for 179 aircraft to replace part of the USAF’s KC-135 fleet in 2011, but the program has since been bedevilled by a number of development problems that are still being resolved.
These have mostly been centred around the boom, although aircraft are rolling off the production line and entering limited service with the USAF as the development issues are being worked out.
Work on the first JASDF tanker began in 2019, the aircraft making its first flight from Boeing’s facilities in the United States in February 2021. Japan’s KC-46s will be used to refuel the JASDF’s fleet of F-15J Eagles, F-2s and F-35A/Bs, and the type’s selection was also driven by its ability to refuel Japan’s Bell-Boeing MV-22B Osprey tiltrotors.
Japan exercised an option for a fourth aircraft in 2020 when it awarded the contract for the third and fourth aircraft, although it has expressed an intention to eventually bring up the fleet to six aircraft.
ILYUSHIN IL-78 MIDAS
The Ilyushin Il-78, NATO reporting name Midas, was conceptualised in the Soviet Union during the Cold War. Based on the Il-76 airlifter, the Il-78 first flew in 1983 and entered service in 1984. Powered by four D-30KP turbofan engines, the Il-78 comes in several variants, differing in fuel offload capacity and retention/deletion of airlift capability.
The Il-78 can offload between 53 and 113 tonnes of fuel depending on variant and whether additional fuel tanks are installed in the cargo hold. Fuel transfer is typically via three UPAZ-1A or -1M refuelling pods to support probe-equipped receivers.
In the Indo-Pacific the Il-78 is in use with China, India, and Pakistan.
China operates three Il-78MPs, these being ex-Ukrainian airlifters modified into tankers after China was unable to acquire airframes from Russia to convert. The first aircraft was delivered to the People’s Liberation Army Air Force (PLAAF) in late 2014 and, despite the war in eastern Ukraine slowing down the conversion work, all three aircraft are now serving with a PLAAF transport regiment operating a mix of Il-76 airlifters and Il-78 tankers based near Wuhan-Paozhuwan.
China’s Il-78s have supported PLAAF fighter deployments, including a 10-hour long sortie by PLAAF Sukhoi Su-35 Flanker-E fighters over the disputed islands of the South China Sea in 2019.
India’s Il-78MKIs are unique in that they utilise Israeli refuelling pods instead of the Russian designs, enabling the Indian Air Force to refuel the mix of Russian and Western combat aircraft in its inventory. The IAF operates six Il-78MKIs with 78 Sqn based at Agra in the northern state of Uttar Pradesh, where they are known as the Mid-Air Refuelling System (MARS) in the IAF.
The squadron was formed in 2003 after India acquired the Il-78s from Russia, with one of them supporting the detachment of IAF Sukhoi Su-30MKIs that participated in Exercise Pitch Black 2018 in Darwin, although the tanker only accompanied the Su-30MKIs for the ferry flight and ended its journey in Indonesia before flying back without landing in Australia.
Pakistan also operates the Il-78 with four aircraft flying with 10 Sqn ‘Bulls’ out of Nur Khan Airbase in the Punjabi city of Rawalpindi. The Il-78s have regularly supported Pakistan Air Force (PAF) deployments overseas including to foreign air shows, and are used to refuel the PAF’s Dassault Mirage III/5 and JF-17 Thunder fighters.
Malaysia is the sole operator of the Airbus A400M strategic/tactical airlifter in the Indo-Pacific region, with the Royal Malaysian Air Force (RMAF) operating four aircraft with 22 Sqn based at Subang in Kuala Lumpur.
In addition to the transport role, the RMAF uses the A400M as a tanker. The type is able to refuel the RMAF’s combat types, including the BAE Hawk 208s, McDonnell Douglas F/A-18D Hornets, and Sukhoi Su-30MKM Flanker-H fighters.
The unit is due to be renamed 8SQN later this year, and has used the A400M in the tanker role during its participation at Exercise Pitch Black 2018 in the Northern Territory refuelling the RMAF’s Hornets.
Malaysia also has two C-130H Hercules converted as tankers, having signed an agreement with Flight Refuelling Limited in 1995 to undertake the conversion. In addition, the RMAF has used its Su-30MKM as a buddy tanker with a centreline pod.
REGIONAL US TANKERS
The US military officially has just two aerial refuelling squadron based in the western Indo-Pacific region – the USAF’s 909th Air Refuelling Squadron operating KC-135Rs at Kadena Air Base in Okinawa, and Marine Aerial Refueler Transport Squadron 152 (VMGR-152) ‘Sumos’ with the KC-130J Hercules based at Iwakuni in western Japan.
The former is part of the 18th Wing based that also operates two squadrons of McDonnell Douglas F-15C/D Eagles, and one squadron each of the Boeing E-3C Sentry AWACS aircraft and Sikorsky HH-60G Pave Hawk helicopters, while VMGR-152 is part of the Japan-based Marine Air Group 12, 1st Marine Air Wing.
Unsurprisingly, both squadrons are heavily committed to supporting increasing US military air movements throughout the Indo-Pacific region. This is not limited to combat squadrons based in the region, as these are often augmented with additional rotational deployments in the form of US Navy and Marine Corps fighters under the Unit Deployment Program (UDP) and other programs.
Additional tanker support is thus needed across the vast expanses of the region, and the USAF maintains a constant cycle of KC-135 and Douglas KC-10 Extender tankers from the US to bases in the region, most commonly to Andersen Air Force Base on Guam and Yokota Air Base near Tokyo.
There are also several regional tanker development or acquisition programs ongoing.
China is developing its Xian Y-20 airlifter as a tanker aircraft as it seeks to beef up its air refuelling capabilities. The PLAAF’s modest tanker fleet has lagged as the rest of its force has modernised, with just a small number of H-6 tanker versions in service until the aforementioned acquisition of three Il-78 tankers from Ukraine.
But a shortage of available Il-76 airframes has stymied PLA ambitions to put more into service, and instead the Il-78 acquisition was also likely used to develop templates for China’s own manufacturing and operational capabilities. The Y-20’s design has clearly been influenced by the Il-76/78, and Ukrainian aerospace designers reportedly assisted in its development.
In 2020 Y-20s with what appear to be wingtip refuelling pods were seen in satellite imagery, and these have more recently been backed up by increasingly clear “leaked” photos of similarly-configured Y-20s, although China has not officially admitted the existence of the tanker version which reportedly carries the Y-20U designation.
Meanwhile, India has its own longstanding requirement for a new tanker aircraft but, like many Indian defence acquisition programs, this effort has been bogged down by funding and political issues. The Airbus A330 MRTT was selected in 2013, only for the government to scrap the whole program in 2016 citing the high cost of the six aircraft.
The country subsequently flagged the acquisition of a combined tanker and AEW&C aircraft in 2017, and then relaunched the tanker bid in 2018. Airbus and Boeing have submitted the A330 MRTT and KC-46A respectively, with the Ilyushin Il-78 being disqualified as the requirements had sought a twin-engine type.
To the north of Australia, Indonesia is also seeking a new tanker aircraft type to replace the small number of KC-130Bs it has in service, which are more often than not used as conventional transports across the expansive archipelago.
In 2018, it was announced that that the Indonesian Air Force (TNI-AU) had appointed GMF AeroAsia – a subsidiary of national airline Garuda Indonesia – for assistance with an in-depth study on Indonesia’s mid-air refuelling capabilities and requirements.
In April 2021 it was announced that the country’s finance ministry has approved an application by its defence counterpart to obtain a foreign loan of up to US$700 million to acquire two tanker aircraft, with the MRTT and KC-46 again expected to be the leading contenders to support refuelling requirements for its fleet of Su-27/30s and F-16s.
This article appeared in the July/August 2021 issue of ADBR.