Commercial Fixed Wing
Communication Breakdown; Situational Awareness
Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Person / Animal / Bird; Ground Excursion Ramp
Human Factors
I was the lead for [for marshaling arrivals and departures at our assigned gate]. The crew and [I] had just finished pushing [an] aircraft and...After closing the flight out; I proceeded to do my pre-arrival FOD walk. As I was walking from the outer [safety ring] to the concourse. I reached down to pick up some FOD.  I heard aircraft engines spool up and become louder and louder. I looked over my shoulder and became startled to realize that an aircraft was proceeding down the lead in line about 10 feet behind me. The crew proceeded without the aircraft being marshaled in. AT the point of realizing the aircraft was still rolling I immediately placed the STOP indicator. (With the wands being crossed properly) Video can confirm these actions. At that point I walked to discard the FOD I had collected on my walk around. I proceeded to the lead in line and marshalled the aircraft the remaining distance to the stop mark.
While performing a post departure FOD inspection at his assigned gate the Lead Marshaler was alarmed by the sound of engines spooking up behind him and only then noted that an aircraft was taxiing into the gate despite his presence in its path and the lack of a Marshaler. He recovered quickly; got the flight crew's attention with a wands crossed 'STOP' signal and then marshaled the balance of their arrival.