Southeast Asia’s leading air force continues to methodically improve to its already impressive fixed wing force.

On 9 August 2015, the Republic of Singapore Air Force (RSAF) conducted what was probably its most important mission to date: flying an armada of fighters, helicopters, transport aircraft, and much more over downtown Singapore to celebrate the nation’s 50th birthday. The highlight of the show was a fleet of 20 Lockheed Martin F-16 C/D aircraft flying in a special “50” formation. The final touch was a lone Boeing F-15SG performing a tight turn over Marina Bay reservoir, afterburners roaring.

Fun aside, the RSAF has been steadily setting the stage for future capabilities since the last iteration of the Singapore air show in 2014. This period has seen the regional situation become somewhat tenser. China has become more assertive about pressing claims to virtually the entire South China Sea, putting it at loggerheads with the city state’s Southeast Asian neighbours Malaysia, Vietnam, Indonesia and the Philippines. Two other key Singapore allies, the United States and Australia, are also concerned about China’s growing belligerence. Not to say a conflict is in the offing – Singapore and Beijing enjoy close ties, after all – but mounting geopolitical uncertainty underlines the need for the robust deterrence represented by the RSAF and its sister services.

Boosting tanker capabilities

Perhaps the most significant news to emerge since the last Singapore gathering is the March 2014 announcement Singapore will obtain six Airbus A330 multi-role tanker transports (MRTT). Singapore’s interest in the type had been rumoured for years. Observers say its four 1960s-vintage KC-135Rs are maintenance intensive.

Given Singapore's use of the F-15SG, which requires a boom for air-to-air refuelling, the country is likely to obtain its A330 MRTTs in a configuration similar to those used by the Royal Australian Air Force (RAAF), which also includes a hose and drogue refuelling pod under each wing. The boom will support types including a potential future Singaporean fleet of F-35s. Indeed, RAAF officials have said Singapore was very eager for Australia to get the boom on its A330 MRTTs operational.

A fact sheet prepared by Singapore's defence ministry reveals the nation's aircraft will be powered by Rolls-Royce Trent 772B engines and delivered with a 266 seat-configured passenger cabin. Airbus Military will perform the conversion work in Madrid.

“The Singapore A330 MRTTs will be converted in Madrid,” says Airbus Military in an email to Flightglobal. “The expertise and efficiencies that the company has accumulated in this complex conversion mean that this is clearly the most effective solution.”

Analysts are positive about the capabilities offered by the new tankers.

“The six new A330s will provide the RSAF with a more modern and capable aerial refuelling platform than its four Boeing KC-135R Stratotankers and a niche complement to its Lockheed Martin KC-130B/H tactical transport/refuelling aircraft once they begin to arrive in 2018,” says Forecast International analyst Dan Darling.

“The A330’s dual-use purpose allows Singapore to have additional troop transport capability in a pinch, but more importantly to maximise its aerial combat capability by providing for longer loitering and patrol missions for its fighter aircraft through their refuelling.”

F-16 upgrade goes to Lockheed, Northrop

Apart from the tanker selection, the last two years also saw Singapore clarify its upgrade plans for its fleet of 60 F-16s. The fleet’s avionics will be upgraded by Lockheed Martin, and the aircraft will also receive active electronically scanned array (AESA) radar in the form of Northrop Grumman’s SABR (Scalable Agile Beam Radar).

At the 2014 show, BAE Systems and Raytheon mounted a spirited public relations effort for their opposing F-16 upgrade offerings, in the hopes Singapore would issue a competitive tender. At that time the pair were riding high. In late 2013 Raytheon had defeated Lockheed in a competition to upgrade the avionics of South Korea’s F-16s, and Raytheon had won the parallel AESA radar competition.

It is not clear if their calls for a tender made an impression on Singapore officials, but now the case is moot. In early December 2015, more news about the Singapore upgrade programme emerged, with the US Defence Department announcing Lockheed has been awarded a $914 million contract via the Foreign Military Sales mechanism to upgrade F-16s for Singapore. It offered few details, but indicated the work will take place in Fort Worth, Texas, and could be completed by June 2023.

Meanwhile, BAE and Seoul had a dispute over the price of the upgrades, which ultimately led to cancellation of the programme and litigation. Eventually the Lockheed/Northrop team won the work. Lockheed and Northrop also have a programme to upgrade Taiwan’s F-16s.

It is not entirely clear how many Singaporean F-16s will be upgraded. In May 2015, the US Defence Security Cooperation Agency (DSCA) published a revised list of equipment related to the upgrade, including 50 Boeing joint helmet-mounted cueing systems (JHMCS), 90 BAE Systems AN/APX-126 advanced identification friend and foe (IFF) interrogator/transponders, and 92 Link-16 terminals.

The number of JHMCS sets and IFF transponders in the May 2015 revised list varied from a previous list issued in early 2014. This previous approval called for 70 JHMCS sets, 20 more than in the revised document. The initial requirement also called for 70 AN/APX-125 IFF transponders, but the revised list increased this by 20 IFF units, and calls for a different standard – the AN/APX-126.

Another uncertainty around the Singapore F-16 upgrade is where, exactly, the work will be done. It is possible, probable even, that a significant amount of upgrading may end up at local MRO firm ST Aerospace, which has notable expertise with fighters. A local solution would mirror the South Korean upgrade programme, which will see the vast majority of the fleet upgraded in South Korea.

In the 1990s, ST Aero oversaw a major – and by all accounts successful – upgrade for Singapore’s former fleet of A-4S Skyhawks to an A-4SU standard. This saw the venerable type’s Pratt & Whitney J52 engines replaced with a non-afterburning version of the General Electric F404. Though Singapore retired the Skyhawk in 2005, ST Aero is involved with MRO work related to Singapore’s fleet of Northrop F-5S fighters as well as the F-16s.

F-15SG numbers shrouded in secrecy

Perhaps the most interesting question about the RSAF involves its F-15SG fleet. Boeing and the government steadfastly maintain the number is 24, but outside observers have long suspected that the true number is higher, perhaps up to 40 aircraft divided between Singapore’s Paya Lebar air base and the USAF base at Mountain Home in Idaho, where a training detachment is stationed.

On 6 August 2014, the FAA registry showed eight F-15SG aircraft were registered to Boeing on 6 August 2014. The aircraft bear registrations N361SG, N363SG, N366SG, N368SG, N373SG, N376SG, N378SG and N837SG. Prior to this, industry observers had already arrived at the view the true number of aircraft was probably 32 and not 24, mainly owing to the range of registration numbers on Singapore air force-registered F-15SGs.

Moreover, on a tour of Korea Aerospace Industries’ (KAI) Sachon factory in 2011, Flightglobal observed the forward fuselage assembly of an F-15 labelled “SG28” – KAI is a key contractor in the F-15 programme. Flightglobal’s KAI visit in 2011, aircraft sightings in recent years and the F-15SGs registered on 6 August 2014, suggest the Singapore F-15SG fleet could number up to 40 aircraft.

Cloaking one’s order of battle in ambiguity is nothing new in the annals of military history. “The benefits of hiding F-15SG numbers for Singapore apply to its strategic calculus that it is better to keep potential state-based threats guessing as to its true capabilities,” says Forecast International’s Darling. “Singapore's power-projection approach to national security strategy dictates first-strike/force-multiplier capability is crucial – and deterrence more so. Any enemy who is aware that Singapore has high-quality capabilities and a well-trained force, but is unsure of the critical mass it is capable of bringing to bear, is a tentative enemy.”

Tiger II to Lightning II

Singapore’s active fighter fleet is rounded out by 26 well-maintained, but ageing, F-5S fighters, which date from the earliest days of the Singapore air force in the 1970s. The type has seen extensive upgrading over the years, but the type’s retirement in the coming years is a foregone conclusion. It is all but certain the F-5 fleet will be replaced by the F-35.

For several years Lockheed has displayed a mock-up of the F-35 at the Singapore Air Show in RSAF markings. Singapore is a security co-operation participant in the programme, giving it access to programme data and allowing it to request special studies. In March 2013 defence minister Ng Eng Heng said an evaluation of the F-35 was nearly completed.

“For the longer term, the Republic of Singapore Air Force has identified the F-35 as a suitable aircraft to further modernise our fighter fleet,” said Ng in 2013. “We are now in the final stages of evaluating the F-35."

Curiously, local media reports in December 2015 quoted Ng as saying Singapore is still in “no hurry” to make a decision to obtain the F-35, and is still evaluating the type. Ng made the more recent comments during a visit to Luke Air Force base.

“Two years ago when we were here, these hangars were not filled (with the F-35s)... within a year and a half, they’ve clocked in more than 3,000 sorties, 5,000 hours – that’s a lot of flying hours,” said Ng. “And that gives us confidence that the programme is progressing on track. So the more mature the programme is, the more steady the production lines for (the F-35s), the more boxes are ticked when we evaluate it, but we are in no hurry to decide.”

Richard Bitzinger, senior fellow at Singapore’s S. Rajaratnam School of International Studies, contends Singapore is just being careful. “The F-35B makes sense to a country that has only a few bases and very few options for dispersed operations,” he says. “Ostensibly, Singapore could set up a number of austere basing sites for operating the B version, including islands off the Singapore mainland. Singapore is probably just being prudent, and waiting until the F-35B goes through its teething with the US military. They’ll probably announce any F-35B acquisitions the same time they place an order for the A version.”

Real Estate woes

Bitzinger touches on one of the key questions surrounding Singapore’s plan to obtain the F-35: the mix of conventional takeoff F-35A variants and short takeoff vertical landing (STOVL) F-35B variants. A major challenge facing Singapore’s air force – and the other arms of Singapore’s military – is the shortage of land in densely populated Singapore.

For the time being the air force enjoys usage of Paya Lebar air base, a single runway facility that was Singapore’s international airport until Changi International Airport opened in 1981. Unfortunately, Paya Lebar rests on extremely valuable real estate in the centre of the crowded island. Apart from the land occupied by the base itself, aircraft movements limit construction heights in nearby areas.

Long term plans call for the closure and redevelopment of Paya Lebar, and the conversion of the existing air force runway at Changi East to a commercial runway. A new airbase will be built on reclaimed land in Changi farther to the east of the existing airport, effectively replacing both Paya Lebar and the Changi East base with one, single base. This will leave Singapore with just two bases earmarked for fast jets: Tengah Air Base in the nation’s west and the new Changi base.

Although Singapore’s civilian runways can be given over to military use in a crisis, and several public roads are designed to serve as runways in an emergency, it is an inescapable fact the Singapore air force has limited basing options. As such, the flexible basing capability offered by the F-35B will have clear attractions for Singapore.

Forecast International’s Darling says Singapore’s caution about the F-35B probably stems more from cost than concerns about the jet itself.

“The long-term funding of such an expensive acquisition is no doubt a key factor in its hesitation to announce its commitment to the pricy F-35B as of yet,” he says. “Balancing costs within the defence budget with an ongoing government campaign to bolster the living standards of citizens is no doubt a consideration. The hope for Singapore is that, over time, unit prices per F-35B aircraft will decline, thus ensuring a more cost-effective purchase in the future.”

UAV progress

Singapore has also been active bolstering its unmanned capabilities. In April 2015 the Elbit Systems Hermes 450 unmanned air vehicle fleet reached full operational capability (FOC), some eight years after the system was delivered to the RSAF. Following the delivery of the UAV to RSAF’s 116 Sqn in May 2007, the pilots, engineers and maintenance crew underwent “intensive training” to allow them to operate the aircraft in line with RSAF procedures, said the Singapore defence ministry at the time the FOC was granted.

The Hermes 450 was acquired to supplement the air force’s Israel Aerospace Industries Searcher and Heron 1 UAVs by providing a vehicle with longer endurance, advanced avionics and better sensors. Key to this is the three-in-one payload, which combines electro-optical, forward-looking infrared and a laser designator in one pod.

“This enables the H-450 to augment our battlefield surveillance capabilities by conducting a wide array of missions such as target acquisition and designation, reconnaissance and battle damage assessment,” said the ministry.

The Hermes 450, however, may not mark the ultimate limit of Singapore’s high-end UAV capabilities. Although it is never publicly discussed, the RSAF is understood to be interested in the Northrop Grumman RQ-4 Global Hawk. Indeed, Northrop executives gave a media briefing about the system at the last Singapore air show.

Deployed in international airspace at the northern end of the Straits of Malacca and above the South China Sea, the Global Hawk, or its Triton maritime patrol variant, would provide the RSAF unprecedented and persistent situational awareness of the region. It is not clear, however, how interested the RSAF is in such a platform, or whether Washington would view the introduction of such a platform into Southeast Asia as destabilising. At this year’s show it will be interesting to see if Northrop again comes prepared to discuss the Global Hawk family.

Southeast Asia’s top AEW&C

The RSAF’s key command and control capability resides in its four Gulfstream G550 airborne early warning & control (AEW&C) jets, which became fully operational in April 2012. These replaced the country’s four E-2C Hawkeyes, which had served since the 1980s. Singapore’s G550s have a similar configuration to the G550 conformal airborne early warning platform operated by the Israeli air force.

Israel Aerospace Industries subsidiary Elta Systems says this offers a mission endurance of 9h when operating at an altitude of 41,000ft (12,500m) and 185km (100nm) from its home base. The aircraft features dual S-band radar arrays at the front and rear, plus L-band sensors on the fuselage side, providing 360˚ coverage. Israel's configuration has six on-board operator stations. The modified G550 also has pod-housed electronic support measures equipment, plus satellite communications and line-of-sight data links. Elta says the airframe modifications have "minimal impact" on the business jet's performance.

Singapore also operates five Fokker 50 maritime patrol aircraft. These are very capable platforms, and have even been deployed to the Gulf of Aden for anti-piracy coalition work. Nonetheless, Singapore has explored the possibility of obtaining former US navy P-3C Orion aircraft.

Singapore has been mooted as possible customer for the P-8A Poseidon, but most observers feel this type is above specification for routine patrol work near Singapore’s shores. Nonetheless, Singapore’s MPA capabilities received a boost when the government approved US Navy P-8As to operate from Singapore. These periodic deployments will improve US surveillance over Chinese activities in the South China Sea, and should presumably give a boost to Singapore’s situational awareness.

Rounding out the RSAF are 10 C-130H tactical transport aircraft, which are a common sight in Singapore skies. Apart from routine transport duties, it has also served in a number of overseas disaster relief missions. It has also participated in recent searches for missing aircraft, namely MH370, a Malaysia Airlines 777 that disappeared in March 2014, and QZ8501, an Indonesia AirAsia A320 that crashed in the Java Sea in December 2014.

Flightglobal’s Fleets Analyzer shows the average age of Singapore’s 10 C-130s is 43 years, with the youngest 29.2 years old, and the oldest 56.4 years. It is probable Singapore will seek a replacement for these aircraft in the medium term. Potential replacements could include the C-130J, A400m, or even the Embraer KC-390.

“Singapore’s armed forces are well-equipped to deal with any local threats,” says Bitzinger.

“With the purchase of up to 100 F-35s, it will continue to be so well into the middle of the century. The challenge is China. If China becomes more militarily present in the South China Sea and more aggressive in using force to back up its claims, that could present a latent, long-term threat to Singapore that Singapore would find hard to compete with. China can simply bring much more force – qualitatively as well as quantitatively – to bear against Singapore or any other Southeast Asian military. Hence the increasing need to hedge against China by inviting the US into a closer embrace, militarily speaking.”