In January 2018 China introduced an army version of their Z-18 naval helicopter called the Z-18A. China has been working on this particular design since the 1980s, when China began producing (under license) the French SA321. The license also included the French Turbomeca Turmo 3C engines which the Chinese produced as the WZ-6. China insists that the Z-18is a Chinese design and not a copy of the SA321. To a certain extent China is correct. While the Z-18 (and earlier Z-8) and civilian version (AC313) share the same shape, weight and three engine configuration as the SA321 the latest Chinese version makes user of many lightweight composite or titanium materials in the airframe and their latest version of the French engines (WZ-6C) are apparently more powerful than the French original and about as reliable. Details of the licensing agreements are not made public but apparently China still honors them to some extent because the AC313 has been offered for export sale. France could block that with litigation and that alone would encourage the Chinese to keep their license deal up to date or at least still acceptable to the owners of the technology.
Meanwhile France retired the last of its SA321 Super Frelon helicopters in 2010. The French Navy had wanted to retire the SA321s since the 1990s, as these choppers date from the 1960s. This finally became possible when, in 2008, it was revealed that a third of the SA321s were unavailable for service because of age related maintenance issues. Then it was revealed that the SA321s also tended to fail at inopportune times in the combat zone.
Only 99 SA321s were built (plus hundreds of Chinese copies), and most were used by nine different nations they were exported to. Designed as a naval helicopter, most ended up serving as troop and cargo transports. The SA321 is a three engine, 13 ton aircraft with a crew of five and a capacity of 27 passengers. Naval versions were often armed (for anti-submarine worl) with four torpedoes or (for surface warfare) two anti-ship missiles, plus a 20mm autocannon. Endurance was four hours. The SA321 keeps flying, especially in China, where the Chinese version has been improved with new materials (the composites) modern electronics and more powerful engines.
China bought some SA-321s in the early 1970s, and by 1976 were working on reverse engineering them and producing their own, illegal, version. The first flight of the SA-321 clone (called the Z-8) took place in 1985. But only about twenty of the Z-8 have been built since then. Too many technical problems, plus the French were none too happy about this bit of theft, and made their displeasure known to the Chinese as well as some willingness to bargain. While negotiating China persisted and in 2010 the Z-8B was in production. At that point only a dozen were built. A more powerful engine, and hundreds of technical improvements, have still not produced a chopper the Chinese army was willing to pay for. The navy was happy with the original SA-321s, and the Z-8 clones, but these operated at sea level.
China persisted and the AC313 soon appeared with improved engines and much improved performance. The AC313 soon showed up as the Z-18. While similar in appearance to the Z-8, the Z-18 was heavier (13.8 tons) and could carry up to 30 personnel or four tons internally and five tons externally. The engines were powerful enough for the Z-18 to operate at high altitudes (as in Tibet). This convinced the Chinese army, which has added electronics that enable all-weather operation. The Z-18A is expected to eventually replace the Russian Mi-17s that have been the backbone of Chinese army aviation until now. The AC313 civilian version has attracted a lot of interest from potential foreign buyers.
For a long time China planned to partner with Russia to build helicopters in China using Russian tech. But it was clear that. While the Russian designs were useful the Western tech was better and the French were willing male deals. The key element in the French Connection was that France was one of the few countries that had developed modern aircraft engine design and manufacturing technology. The Chinese felt they could not trust the Russians to help with this and, besides, the French had better tech than the Russians.