The AL-31F can operate in a wide range of reliably altitudes and flight speeds. The engine works reliably in conditions of deep surge of the air intake with M=2 as well as in flat, straight and inverted spins. The engine ensures unique aircraft maneuverability including super dynamic aerobatics in negative speeds up to 200 km/h.
The AL-31F provides high gas dynamic stability and strength which maintain engine reliable performance in extreme condition of inlet distortion. The AL-31F can be manufactured both in standard and tropic version.
Reports of deliveries made through 2002 and planned transfers of large quantities of aircraft of the Su-27/30 family permit a relatively accurate estimate of this segment of the AL-31F engine market. We use the average price of $2.8 million per engine. The actual price fluctuates between $2.7 million and $3 million, but some of the payments, especially in the early 1990s, were made by commodity deliveries or on a clearing basis. Twenty eight Su-27UBK combat trainers were delivered to China in 2000-2002 by way of payment of Russian government debts. We estimate the price of AL-31FP engines for Su-30MKIs at $3 million.
It should be noted that the standard international practice is to deliver 30% of reserve engines along with a commercial batch. There has been no information in the Russian press about such deliveries, but if we assume that engines were delivered on such a scale - either along with commercial consignments or shortly thereafter - the delivery of the 350 AL-31F engines to China, India and Vietnam installed on aircraft would have been followed by the shipment of approximately 100 engines, a value of up to $280 million. With the engines being used in the mountain conditions of high humidity and temperatures, and with Chinese and Indian pilots currently lacking the necessary experience .We already know that China has chosen the AL-31F engine modification with the low-set unit arrangement - the AL-31FN - for its J-10 light fighter, developed from Israel's Lavi project. The Russian press has reported a contract for 300 such engines. Sometime in 2005-2007, when the fleet of Su-27/30/J-11 heavy fighters reaches 350 units, China will need to manufacture 600-800 fourth-generation light fighters to balance its Air Force, not counting probable exports (primarily to Pakistan and Iran). This means that total demand will reach 1,000 AL-31FN engines at the nominal price of $2.8 billion. It is clear that China is unlikely to import such quantities of engines, especially after the license for their production has been sold to India. Therefore, we can expect that, within a few years, when the question of launching the large-scale production of J-10 appears on the agenda, China will want to acquire the right to assemble AL-31F or AL-31FN engines at its own facilities. A less favorable option for Russia is that China will manage to develop its own analog of AL-31. However, even in this case, Russia will be able to deliver up to 300 contract engines and probably individual high-tech components for the Chinese analogs.
It is less likely that AL-31Fs will be installed on India's LCA fighters. First of all, India is trying to develop its own Kaveri engine. Its chances are poor, but that does not greatly improve the outlook for AL-31F. The problem is that the LCA project has dragged on for too long and, as a result, the prototype has grown obsolete before the beginning of its serial production and even before the end of its testing. Given India's plans to import large quantities of Su-30MKI multi-use fighters, MiG-29K naval fighters and Mirage 2000s, the scale of funding for the LCA project rules out the possibility of any serial production in the near future.
Thus, if reports about the contract for 300 AL-31FN engines are true, at present we can assume with a high degree of certainty that deliveries of engines and their components, combined with the possible transfer of documentation and technologies for the production of AL-31Fs in China for its national J-10 fighter, may reach $800-850 million.
Market of AL-31F upgrading
The AL-31F engine was developed in the mid-1970s for fighters with a takeoff weigh of 23 tonnes and maximum takeoff weight of 28 tonnes. Hence two engines with a maximum thrust of 7.8 tonnes and afterburning thrust of 12.5 tonnes guaranteed Su-27 interceptors a fairly good thrust-to-weight ratio. Later the Sukhoi Design Bureau derived a number of upgraded modifications with greater capabilities from the basic model. Moreover, in this sense Su-27 not simply shared the fate of the majority of successful fighters of the third and fourth generations that went through several stages of upgrading but proved to be a very flexible aircraft with a relatively ample advancement potential. Traditionally such advancement implies the enhancement of the strike potential and the addition of a second pilot. Clearly this implies an increase in the regular and maximum takeoff weight of the aircraft. On the average during the lifetime of a fighter family the weight grows at the rate of one percent a year and the Su-27/30 series definitely fits the pattern. The general parameters of aircraft of this series are shown in Table 3.
It is paradoxical that while the combat capabilities of Su-27/30 fighters have been dynamically boosted, efforts to enhance the thrust of AL-31F engines have been lagging behind badly. As a result such a crucial parameter for aircraft of the fourth generation as thrust-to-weight ratio is unsatisfactory in the latest modifications of Su-30. Moreover, the fact that in India and China Su-30MKI and Su-30MKK are used in a hot and humid environment and often in mountainous conditions makes things even worse. These conditions further undermine the thrust-to-weight ratio of the aircraft delivered of foreign customers.
This alone creates sufficient prerequisites for replacing AL-31F engines with more powerful ones in four plus generation fighters delivered to China and India in the foreseeable future. Such a replacement may be conducted simultaneously and in a package with building up the computer capabilities of onboard radioelectornic systems and offering new air-borne weaponry. Russian upgrading programs should offer an edge over Israeli projects sponging on Russian platforms.
In addition to adjusting Su-30MKI and Su-30MKK to modern thrust-to-weigh ratio requirements the engine thrust enhancement may come handy in the context of the probable integration of longer range and consequently heavier weapons, especially of the air-to-surface class. The PJ-10 3-tonne anti-ship missile may become such a weapon for the Indian fighters and the air-borne version of the Moskit (SS-N-22 Sunburn) ship-to-ship missile for Chinese. In general Russia should launch work now to offer competitive packages of upgrading fighters delivered to China and India with the enhancement of their energy capabilities as their crucial component.
The market of AL-31F engines with an enhanced thrust is not limited to the Su-30MKI aircraft sold under delivery or license contracts. The following conclusions can be made about market volumes of these engines in the 1990s and in the near future, based on the most conservative estimates of the price of the AL-31F and its modifications, and the demand of the Chinese and Indian Air Forces for aircraft of the Su-27/30 series:
The nominal price of engines transferred in the framework of contracts completed in the 1990s was $980 million. The price of engines transferred in addition to the delivery contracts is estimated at up to $280 million.
According to open sources, delivery contracts provide for the transfer of 138 AL-31F and AL-31FP engines, worth up to $385 million, in 2003-2005.
The biggest revenues are expected from the license contracts for the production of J-11s in China and Su-30MKIs in India. The minimal price of the engine component of the deals is about $1.7 billion.
China's minimal need for AL-31FN engines for launching the production of the J-10 light fighter is 300 units, worth $850 million. Production on a larger scale will require the acquisition of a license for the manufacture of AL-31FN engines at local facilities or the development of a Chinese analog of the engine.
Thus, even according to the most conservative estimates, the AL-31 engine market in the coming decade may run up to some $3 billion.
The 117Ñ engine is a deep modernization of the AL-31F engine (generation 4++)
The 117Ñ is an aircraft turbofan engine with a variable thrust nozzle of generation 4++ developed by NPO Saturn to the Sukhoi Design Bureau order for the export Su-35 fighter.
The 117Ñ engine is a deep thrust-life modernization of the AL-31FP, which will be installed on the latest Sukhoi Su-30/Su-30MKI aircraft.
The modernized engine thrust has been increased by 16% compared to the base AL-31FP engine, and has reached 14500 kgf, the lifetime has been doubled, up to 4000 hours.
Such high parameters, on retention of the overall dimensions and weight, are attained due to application of an absolutely new high-tech low pressure compressor with increased air flow and efficiency, a new high-performance turbine of increased reliability with an improved blade cooling system and digital engine control system integrated with the aircraft control system.
The declared parameters have been confirmed in the course of the demonstrator engine bench and flight tests. A special NPO Saturn achievement is a stable and reliable operation of the engine at Mach number exceeding 2, which was obtained in the course of the demonstrator flight tests.
As for geometry and attachment points on the aircraft, the 117Ñ engine conforms to its predecessors, generation 4 AL-31F and AL-31FP engines. This makes it possible, with slightly developed engine nacelles and equipment, to use the 117Ñ engine for modernization of the entire aircraft fleet of previously manufactured Su-27/Su-30, operational both by the Russian and foreign Air Force.
On 19 February 2008, a new 117Ñ-powered Su-35 aircraft successfully performed its first test flight.