Friday, 1 July 2011

China very close to jet-engine breakthrough

In a new defense paper released few days back, it is estimated that China will achieve complete self-reliance in manufacture of jet-engines also called "low-bypass turbofans" within the next 2-3 year and may start mass producing these engines within 5-10 year.

China is treating engine development as a high priority and plans to invest 10 billion RMB (US$1.53 billion) into jet engine research and development over the next 5 years.

There are few reasons as to why China wants this ability really badly.
  • To overcome the Russian bogey
    • Poor Russian spares and service
    • No third party transfer without Russian permission
    • Increasing demand for engines by Russian airforce
  • Increase export potential of cheap 4th-5th generation aircraft's
  • Match US airforce by mass producing 5th generation fighters to take on F-35's and F-22

Now let us take each point one by one

To Overcome Russian Bogey

The Chinese aerospace industry is driven by four key strategic imperatives as it pursues the ability to manufacture large volumes of high-performance tactical aircraft engines: (1) parts dependence avoidance, (2) Russian supply unwillingness, (3) aircraft sales autonomy, and (4) poor Russian after-sales service. First, China likely seeks to avoid dependence on Russian suppliers for vital parts. Chinese leaders will not want the country’s most modern fighter aircraft to be dependent on foreign inputs for a core system such as propulsion. Second, Russia’s own armed forces are likely to buy significantly more of its jet engines in the next 10 years than they did over the 20 years since the Soviet Union dissolved. This is an important development given that the collapse in military procurement after the Soviet Union fell was the key driver of Russian jet engine sales to China.

The Russian Air Force’s plans to enhance its aircraft through refurbishment and re-engineering of existing systems and acquisition of new platforms like the SU-34, SU-35, and T-50/PAK FA could stretch Russian engine makers to the point that they have little export willingness, and perhaps restrained export capacity. The Kremlin, which controls Russia’s jet engine makers, will likely prioritize the export of entire aircraft such as Sukhoi Flankers that require advanced engines and the Indo/Russian 5th generation fighter project, which will also demand the most advanced engines Russia’s defense suppliers can produce. The bottom line is that the combination of new Russian Air Force aircraft purchases, continued exports of late model Flankers, and Russia’s joint 5th generation fighter project with India will stretch suppliers enough that even if the People’s Liberation Army Air Force (PLAAF) can get some advanced Russian engines, it likely will not be able to obtain enough to support its desired levels of aircraft production.

China has had painful experience with poor Russian after-sales service for components, e.g., engines. This includes engineering and spare parts support that is expensive, delayed, or simply nonexistent and manuals that are limited, in Russian only, or not available at all.

Increase export potential of cheap 4th-5th generation aircraft's

China is a growing exporter of advanced combat aircraft, as shown by its recent deals to sell FC-1 and J-10 fighters to Pakistan, and will not want foreign engine suppliers having veto power over its arms sales. A major hang-up in the FC-1 deal was that the aircraft uses the same Russian-made RD-33 engines as the MiG-29, but sells for a much lower price and is thus a threat to Russian aircraft exports in the developing world. Russia finally granted China permission to make the FC-1 sale to Pakistan, but the experience almost certainly taught Chinese aircraft makers that it will be much easier to export Chinese-made aircraft if they use Chinese engines.
This is especially true given the fact that China’s J-10 and J-11B (if SAC is permitted to export it) are comparable to existing Russian tactical aircraft exports and would likely be formidable competitors in terms of price and capability. We note here that a January 2011 editorial in Nanfang Daily anticipates China becoming a major jet engine exporter within the next 10 years.High aspirations by no means imply the ability to actually achieve the desired capability, but these sentiments shed light on the broad importance Chinese policymakers and thinkers place on bolstering domestic jet engine production capabilities.

Match US airforce by mass producing 5th generation fighters to take on F-35's and F-22

The lack of a sufficient supply of reliable domestically made jet engines could significantly impede future production of the J-10, J-11, J-15, and J-20 fighter aircraft. The J-20 program especially needs domestic engine development and production breakthroughs because the Russia appears reluctant to sell the 117S series engines that could enable the J-20 to have sufficient power to allow the aircraft to supercruise (sustain supersonic flight without using inefficient afterburners) and match the performance of 5th-generation fighters such as the Lockheed Martin F-22 and Sukhoi T-50/PAK FA.

China's Problem

China’s attempts to mass produce P&W F100-class jet engines and develop an engine powerful enough to give the J-20 true 5th generation performance levels face a range of technical and process challenges. On the technical side, Chinese gas turbine researchers say weaknesses remain in turbine casting, powder metallurgy for creating turbine disks, and molding hollow titanium parts.
Source: Defense Manufacturing Technology, USCC, China SignPost™

While this systemic component of Chinese turbofans remains uncertain, however, the techniques and processes to support their manufacture are clearly improving. Chinese gas turbine experts say the country’s aerospace industry has improved its jet engine manufacturing abilities in key areas, including
  • Precision cutting, welding, and machining, e.g., five-axis milling for production of turbine blades.
  • Special materials blade production. China’s largest turbine blade production facility, located at Xi’an Aero-Engine, can now undertake mass-production of turbine blades made from superalloys, titanium alloys, cobalt alloys, and stainless steel. The turbine blade quality rate is now said to exceed 95%.
  • Hollow fan blade production. China is entering the nascent stages of being able to produce hollow fan blades. Hollow titanium fan blades are 15-20% lighter than their equivalents and make an engine more fuel efficient. They also reduce rotating mass and allow a tactical aircraft engine to spool up more quickly during maneuvers.
  • Greater automation. This improves standardization and efficiency.
  • Process modeling. Computer-aided process modeling help manufacturers anticipate problems with materials, welds, and behavior of parts under heat stress. Flagging potential trouble spots before machines are started helps save time and money and also ultimately helps produce a higher quality, more durable engine.
  • Enhanced ability to use numerically-controlled milling machines to produce turbine disks.
  • Better ability to produce high-quality, standardized spare parts. Reliable access to such parts is essential to supporting aircraft performance, particularly at the high and unpredictable operational tempo inherent in many operational scenarios. Spare parts have traditionally represented an area of weakness in China’s aviation industry.
Still unclear, however, are key design, system, software, and reliability aspects of engine systems and components. Vibration testing of components is important (e.g., under high-G forces for military engines). It is difficult to determine China’s stage of development for Fully Automatic Digital Engine Control (FADEC), or the capability of the engine to communicate with the cockpit; and for Engine Control Units (ECU), the “brain” of the engine, which helps it to regulate itself.

If China’s engine makers can attain the technical capability level that U.S. manufacturers had 20 years ago, China will be able to power its 4th generation and 5th-generation aircraft with domestically made engines (3rd and 4th-generation in Chinese nomenclature, respectively). These developments would be vital in cementing China as a formidable regional air power and deserve close attention from policymakers.

Read The Complete Report At China Post

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