The Chengdu J-20 "Mighty Dragon" could have problems taking 'flight'  after it was announced that Ukraine will halt the takeover of a domestic aircraft engine maker by a Chinese company. That move by the government in Kyiv seems to be in response to U.S. objections over the prospect of important military technology being accessible to Beijing.

According to a report from Nikkei Asia, Kyiv will return control of Motor Sich to Ukraine and essentially end efforts by Beijing Skyrizon Aviation to take management of the company.

At issue was that Beijing Skyrizon isn't a private firm, but rather is an extension of the People's Liberation Army (PLA) military-industrial arm.

"The Motor Sich enterprise will be returned to the Ukrainian people," Oleksiy Danilov, head of Ukraine's National Security and Defense Council, said after a March 11 meeting. "It will be returned to the ownership of the Ukrainian state in a legal, constitutional way in the near future."

Had the sale gone through it would have allowed China to obtain a key defense technology that has reportedly eluded Beijing for decades. It has been one of the few remaining sectors where the United States and its allies have managed to retain a competitive advantage over China.

China's J-20 Stealth Fighter Has a Flaw 

Breaking Defense reported that for many years, the proverbial "Achilles' Heel" of Chinese airpower has been Beijing's perennial inability to design and build reliable military jet engines. The PLA found that despite its best modernization efforts it has still had to rely on off-the-shelf engines imported from Russia. To break that dependence on imports, the PLA essentially adopted a mantra that if it couldn't develop it – as in the engines – it would buy a company that makes them. In this case, it was the Motor Sich engine production conglomerate.

This has been deemed crucial as China has sought to develop a state-of-the-art fifth-generation fighter. However, the J-20 may look like a modern stealth fighter and may have even been developed from technology stolen from Lockheed Martin's F-22 Raptor and F-35 Lightning II, yet in test flights, the aircraft flew with two Russian-made Salyut/Lyulka AL-31F jet engines. Those are the same engines installed in the Su-27/30 aircraft as well as China's J-10. It is third-generation propulsion technology developed in the 1980s to power the fifth-generation fighter.

Enter Motor Sich

Based in Zaparozhiye, Ukraine, Motor Sich is one of the largest aero-engine enterprises to be created following the dissolution of the Soviet Union nearly thirty years ago. More importantly, it has been described as one of the only companies that could design and build a reliable and efficient engine to meet the needs of Beijing. As Breaking Defense also reported, the other major aero-engine companies from the former Soviet Union are all in Russia but have lost so many personnel that current Russian engine programs end up being cooperative efforts that are anything but efficient.

Beijing isn't reportedly pleased by the decision, but Kyiv has opted to prioritize its relationship with a crucial security partner.

"Ukraine, being in a state of war, cannot afford to hand over the enterprise, on which the Ukrainian defense capability depends, into the wrong hands," Danilov said in a television appearance the following day, according to local media.

As a result, not for the first time, the J-20 is looking like a Not-so-Mighty Dragon, at least if it continues to rely on engine designs older than its pilots.

Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites. He regularly writes about military small arms, and is the author of several books on military headgear including A Gallery of Military Headdress, which is available on Amazon.com.