Yes, it is a mandatory safety requirement for commercial pilots to perform a pre-flight walk-around inspection before every single flight. Even though highly trained maintenance crews and mechanics service the aircraft between flights, the Captain or First Officer must personally verify that the plane is airworthy. During this "walk," the pilot looks for visible issues such as fuel or oil leaks, bird strikes, tire wear, or damage to the fuselage and wings. They check that all access panels are secure and that critical sensors (like Pitot tubes) are unobstructed. This ritual is more than just a formality; it is the final line of defense in aviation safety. By signing off on the pre-flight checklist, the pilot takes legal and professional responsibility for the safety of the aircraft, ensuring that no technical detail—no matter how small—has been overlooked before taking to the skies.