China’s long-serving aircraft carrier, the Liaoning, boasts a small fleet of troubled J-15s and, as of 2016, only 25 qualified pilots. Now, as the Chinese test and expedite production of two new domestically developed aircraft carriers, they face a number of significant challenges. Their goal is to become a true “blue water” Navy. But they still have much ground to cover—no matter how many carriers they can field.

On Sunday, the People’s Liberation Army-Navy (PLA-N ) launched a new recruitment effort. Its aim is to end the carrier-based pilot shortage, as the nation prepares to triple its carrier presence and accompanying squadrons.

“The highlight of this year’s recruitment is the selection of future carrier-borne aircraft pilot cadets. Through shifting from ‘shore-based’ to ‘carrier-based’ standards, the PLA Navy aims to build a pilot recruitment system with Chinese naval characteristics that can adapt to carrier-borne requirements,” the official statement from the Chinese military reads.

However, even if this new recruitment push for capable pilots is successful, it might not be enough to make China’s carriers a formidable presence even in their own regional waters. To begin with, China’s new home-built carriers still rely on diesel-electric propulsion systems. Consequently, their operational area is restricted by the need for constant refuelling.  A Navy that is beholden to fuel limitations and is therefore forced to remain close to friendly shores is often referred to as a “green water” force (Navies that don’t face such restrictions are called “blue water”).

In other words, even if China manages to recruit enough pilots and build enough aircraft to pack these carriers to the gills with personnel and ordnance, they still offer little in the way of force projection outside of the region’s hotly contested waters. Their potential naval dominance in the South China Sea does indeed pose a threat to international commerce. And yet it lacks the diplomatic intimidation offered by America’s nuclear-powered supercarriers, which can deploy formidable firepower anywhere in the world within a short notice.

However, even the range limitations of China’s carriers don’t represent the biggest problem the PLA-N faces when it comes to Naval aviation: the real problem is the planes themselves.

In July, reports emerged that China was looking to rapidly develop a new carrier-based fighter to replace the J-15, which is based on a reverse engineered Su-35 prototype secured through Ukraine. The J-15 is said to be highly maneuverable while boasting a higher top speed and operational ceiling than America’s speediest fighter, the F-15. However, despite the push to convey an image of the J-15’s air superiority, the aircraft has proven considerably less reliable than the Su-33 it’s based on. A number of recent crashes have placed its future in question. Further, despite its capabilities on paper, the launch apparatus utilized on China’s carriers restricts the payload a J-15 (it’s the heaviest carrier-based fighter in the planet).

It’s expected that the J-15 will be replaced by their forthcoming J-31 program, a copy-cat aircraft based on stolen F-35 plans. Nonetheless, it will take years before J-31s join carrier operations. Thus, with J-15s reportedly proving unreliable, China finds itself in a difficult position: with new carriers on the way, a large-scale pilot recruitment effort, but no reliable aircraft.