The mission statement of the US Air Force emphasises Global Vigilance, Global Reach and Global Power. The Indian Air Force (IAF) has rather more modest aspirations. Apart from its abiding concerns regarding China and Pakistan, it needs adequate operational capability across India’s expanded area of strategic and economic interest. However, even this limited region extending from the Persian Gulf to the Malacca Strait has been beyond the reach of IAF aircraft for most of its history.

For many years after Independence, the Indian strategic mindset remained primarily defensive and was concerned mainly with how to react to a possible incursion or attack from a hostile neighbour. Gradually the military establishment began to adopt a more proactive stance. However, since IAF aircraft were limited to bases in national territory, their combat radius was a paltry 350 km or so for aircraft such as the MiG-21 that formed the bulk of the fleet. This was nowhere near enough to reach all of Pakistan, leave alone China. Gradually deep-strike aircraft like the SEPECAT Jaguar and multi-role fighters like the Dassault Mirage 2000 and the Sukhoi Su-30MKI were inducted. Although these could cover Pakistan, much of China still remained out of reach. The IAF’s latest and much-delayed fighter, the Hindustan Aeronautics Limited’s (HAL) Tejas Mk 1 light combat aircraft, is comparable to a MiG-21 variant with a combat radius of just about 300 km without external tanks.

Therefore, in the year 2000, the IAF decided to purchase flight refuelling aircraft (FRA) as part of its efforts to enhance its offensive potential and become a true strategic force. This was a remarkable shift from the late 1970s when the IAF actually sought to remove the aerial refuelling plumbing fitted in its Jaguar aircraft. Nowadays most military aircraft come with inflight refuelling capability.

FRA to the Fore

The process of transferring aviation fuel from one aircraft to another in flight has various names such as air-to-air refuelling (AAR), aerial refuelling, inflight refuelling and tanking. The tanker, more properly called FRA, can transfer fuel to any kind of fixed or rotary-wing aircraft that has the necessary equipment. All major air forces now have FRA because they are a relatively simple yet powerful means to boost the capability of airborne platforms. Rightly reckoned as force multipliers, they convey considerable tactical advantages to the receiver aircraft. For instance, the receiver can remain airborne longer, which increases its combat radius or time on station. Alternatively, it can lift its maximum payload of weapons, cargo or personnel and minimum fuel (to stay within its take-off weight limit) and draw enough fuel only after getting airborne. Therefore fewer aircraft will be needed to deliver the required load. Yet another option in case of a short runway is to take-off with the required payload with minimum fuel and refuel once airborne.

A nation such as India, which shares long borders with potentially hostile neighbours, can base its main strike aircraft deep in the hinterland, safe from long-range artillery, multibarrel rockets and missiles, which render forward bases vulnerable. Pakistan, being a much smaller nation, lacks depth and hence does not enjoy this advantage.

There is also an important psychological benefit from FRA. A combat pilot who can count on quick refuelling from a nearby tanker will be far more confident during the fuel-guzzling combat phase than an opponent who must constantly worry about fuel remainder.

SINCE THE IAF SOON FOUND THAT AAR CAPABILITY BRINGS IMMENSE OPERATIONAL GAINS IT FELT THE NEED TO ACQUIRE ADDITIONAL FRA ON PRIORITY

There are two main systems by which AAR is achieved. While ‘hose-and-drogue’ is the simplest and most common method to adapt to existing aircraft, it is fairly slow in the transference of fuel. However, two to three aircraft can be refuelled simultaneously. On the other hand, the ‘flying boom’ method features much faster fuel transfer but requires a dedicated boom operator and can refuel only one aircraft at a time. Both systems require trained aircrew that can approach the close proximity of the tanker, refuel and disengage without endangering either platform. In theory, repeated AAR can keep the receiver aircraft airborne indefinitely. However, in practice, factors like crew fatigue, engine oil consumption and other running limits come into play.

The Il-78MKI Flies In

The Su-30MKI was meant to give the IAF enhanced combat capability against the Chinese threat. With deliveries and orders amounting to 272, it will be the mainstay of the combat fleet for the foreseeable future. But its range is only about 3,000 km, meaning it cannot engage targets more than 1,500 km away; whereas the one-way distance from Kolkata to Beijing is about 3,200 km and to Shanghai over 3,400 km. The aircraft’s combat radius can be increased by carrying less weapons and more fuel, but that implies reducing the punch. Obviously the IAF cannot claim a credible offensive capability against China without the increased reach that FRA platforms confer. Therefore, in 2003-04, the IAF inducted six Ilyushin II-78MKI tanker aircraft and they equip 78 MARS Squadron located at Agra. MARS stands for Mid Air Refuelling Squadron.

The II-78MKI is a four-engine jet based on the II-76 platform. It is a dedicated tanker, custom-built for the IAF in Uzbekistan and fitted with an Israeli hose-and-drogue fuel transfer system. It carries extra tanks to enhance its total capacity and can refuel six to eight Su-30MKI aircraft per mission. While the basic II-78 is difficult to switch from tanker to transport role, the variant that the IAF has can be quickly converted into a transport aircraft by sliding out one or both auxiliary fuel tanks. Russia is also developing an improved variant called the II-78MK-90 powered by upgraded turbofans. It has a digital automatic flight management system and glass cockpit and can operate from unpaved airfields.

Since the IAF soon found that AAR capability brings immense operational gains it felt the need to acquire additional FRA on priority. That’s when the problems began.

Urgently Needed: Airbus A330 MRTT

In 2006, the IAF issued a request for proposal (RFP) for six new FRA and the Airbus A330 multi-role tanker transport (MRTT), based on the A330 airliner, was selected. But the RFP was scrapped in 2009 because the Ministry of Finance had reservations about “the competitiveness of the bids and the reasonableness of the price”. Another RFP was floated in 2010 and this time both the A330 MRTT and the II-78MKI cleared comprehensive field trials. Following the subsequent commercial evaluation, the A330 MRTT again emerged as the preferred tanker in 2013. However, commercial negotiations over the estimated $2 billion deal have dragged on with no end in sight.

It would certainly be preferable for the IAF to acquire the same type of tanker it already operates, the II-78MKI, and save on investment in fresh maintenance facilities, especially since this aircraft costs considerably less than the A330 MRTT. However, when the lifecycle cost is factored in, the A330 MRTT wins hands down.

The A330 MRTT is a modern product of French technology and a generation ahead of the II-78MKI. Thanks to its widebody fuselage, it has a remarkable payload capacity of up to 45 tonnes or 300 fullyequipped troops or 130 stretchers in the medevac role. It carries 111 tonnes of fuel in its wings, adequate for its own needs, as well as to refuel up to eight combat aircraft. Its advanced Aerial Refuelling Boom System (ARBS) allows the fastest transfer of fuel at the rate of 4,600 litres per minute to the receiver aircraft. The tanker also offers other refuelling options like under-wing hose-and-drogue refuelling pods and/or a fuselage refuelling unit, thus catering to a variety of receiver aircraft.

THE INDIAN AIR FORCE IS OF THE VIEW THAT SINCE THE A330 MRTT CONTRACT IS OF VITAL OPERATIONAL NECESSITY, IT SHOULD BE INKED WITHOUT FURTHER DELAY

The A330 MRTT can perform various roles in the same mission without reconfiguration because, unlike the II-78MKI, it does not need additional fuel tanks and its cargo or passenger carriage space is always free. This makes it possible to provide comprehensive support to a combat squadron proceeding on detachment since the same A330 MRTT can refuel the fighters as well as ferry essential maintenance personnel and servicing equipment.

The A330 MRTT has a range of 14,800 km and a cruising speed of 860 kmph. It offers excellent fuel economy since it has two engines against four on the II-78MKI. It can remain airborne about 15 hours at cruising speeds against just over ten hours for the II-78MKI. Therefore, if the tanker needs to orbit on station or fly some distance before it can transfer fuel, the A330’s lower fuel consumption rate offers much more transferable fuel.

Maintenance support also should not pose a problem because the state-owned carrier Air India operates a large fleet of A330 airliners. As of February 2016, the A330 MRTT has attracted 49 orders of which 27 have been delivered. Airbus expects to deliver the first A330 MRTT to the IAF within three years of signing the contract, and the remaining five within another 15 months.

IAF Imperatives

Overall, the A330 MRTT features performance far superior to the IAF’s II-78MKI tankers. Moreover, the IAF is experiencing significant problems with the product support of the II-78MKI’s original equipment manufacturer. The fleet serviceability is often low due to tardy supply of spare parts. Since this situation is common to most Russian origin platforms there is no reason to believe it will improve. Therefore, to discount the A330 MRTT’s numerous advantages, including life-cycle cost and favour the II-78MKI because it comes with a lower initial price tag, amounts to being penny wise pound foolish.

Some sources indicate the A330 MRTT contract may be on low priority because of paucity of funds. However, this ignores the operational imperatives since the People’s Liberation Army Air Force (PLAAF) of China is augmenting its tanker fleet of ten Xian HY-6U aircraft with three refurbished II-78 aircraft that it ordered from Ukraine in 2011. China is certain to induct more FRA in pursuit of its dream of regional dominance.

In frustration, the IAF has now asked the Ministry of Defence to reach a decision, one way or another. The IAF is of the view that since the A330 MRTT contract is of vital operational necessity it should either be inked without further delay or at least scrapped so that the whole process can begin a third time.

The IAF’s angst is understandable because its existing II-78MKI tanker aircraft are grossly inadequate for its large fleet of Su-30MKIs, Mirage 2000s, Jaguars and MiG-29s. It calculates that major operations anywhere in the region or against China would need another dozen or so FRA. That is why the RFP has an option for an additional six aircraft. The IAF plans to deploy the new A330 MRTT aircraft at the IAF base at Panagarh, West Bengal, renamed as Air Force Station Arjan Singh. The Mountain Strike corps of the Indian Army, which is expected to be raised by 2021, will be located at Panagarh. Without these FRA, operations against China would be seriously hamstrung because very few IAF combat aircraft might hope to reach their targets.