"But the triumph was short-lived. A flurry of close-ups of the parked fighter jet taken by members of the public suggested its build quality and stealth capabilities were suspect, to say the least.Some far from hi-tech bolts and what appeared to be filler between panels prompted mockery on social media. Apart from aesthetics and safety, this would render the plane's fuselage detectable to radars, negating its stealth ability.What is the Su-57?The Su-57 was meant to rival the fifth-generation fighter jets of other countries, particularly the U.S. But despite a decades-long development and testing program, it has yet to prove itself.Russia claims the aircraft has fifth-generation capabilities, which means it should have ultra-high maneuverability, supersonic speed without using afterburners, and, most importantly, stealth technology.The plane has been presented as Russia's most modern fighter jet.