Genuine Factory approved Parts carry a warrantee and an assurance that it meets OEM standards . Just any aftermarket No name, is lucky to fit with no comeback. Some Brand names like Koni or Bilstein Brembo may be better than original There would be oil filter brands that can be relied on and SOME may even be superior to original, but plenty I would NOT fit if they were free. Especially on an aeroplane. ,IF the fit of the thread on the nipple is not good, check why.