B737-500
Maintenance Airframe; Maintenance Powerplant
Confusion; Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Object
Aircraft Aircraft Damaged; General Maintenance Action
Company Policy; Equipment / Tooling; Human Factors; Procedure
After pushback and leak check of another aircraft; I then drove the Maintenance van to the gate to park Aircraft X. Upon arrival at gate; I then verified that there were no obstacles in the parking area. I then parked the maintenance van in the safety area to the aircraft's left-hand side. As I walked from the van to the tug; my direction of travel took me under the jetway. As the B737-500 aircraft arrived; I stepped up on the tug forward of the right-hand seat. Using the illuminated wands; I then began directing Aircraft X in; constantly scanning from the nose tires; to the [guide-in] center-line and wingtips; [while] bringing Aircraft X to a stop line; the most noticeable one to me from my position. I never recognized the -500 stop line. In the dim lighting; my vision was on the only visible stop line [nearest] to me; resulting in ground equipment impacting Aircraft X; denting the inlet of #1 Engine at the 11 o'clock position. We then took Aircraft X back to the hangar and removed the inlet. Graveyard [shift]. [Suggest] having better lighting; bigger; brighter contrasting colors on the stop lines. Some color more noticeable than yellow and black in the dim light. Having at least two people to park an aircraft; the second person to stand off to the side of the correct stop line with the chocks; thus giving a better visual reference to the person directing.
A Mechanic waved in a B737-500 aircraft into a terminal gate beyond the stop line for a -500 aircraft resulting in damage to the inlet cowl on #1 Engine.