Flight crew reported the hold short line signage for Runway 33 at DET airport is confusing and could result in a runway incursion.
Synopsis
Flight crew reported the hold short line signage for Runway 33 at DET airport is confusing and could result in a runway incursion.
Narrative
Taxiing for takeoff to Runway 33 at DET on Taxiway A; we were instructed to cross Runway 25 and Hold Short of Runway 33. After crossing Runway 25; signage to the side of the taxiway displayed 33-APCH"; with a holding position marking painted on the taxiway; adjacent to the signage. I stopped the aircraft at that point. Looking forward towards the runway; there was no separate holding position signage or taxiway hold marking for the runway; other than the APCH hold signage where we were situated. It is unusual for an APCH hold position to also be a runway holding point position. Normally an APCH hold is located at a separate location; prior to the runway. This created some confusion as to why there was no "15-33" signage or runway hold position; closer to the runway. Nevertheless; we remained at the 33-APCH location; until we were cleared for takeoff.If the 33-APCH sign for Runway 33 at DET; is also supposed to be the runway holding point; then it would seem more appropriate for the signage to display "15-33"; along with a runway hold marking on the taxiway; rather than a "33-APCH" sign with a hold marking on the taxiway.During VMC weather days; the APCH sign could be disregarded; since no low IFR Instrument approaches would be conducted; and no instructions from ATC to hold short of the Runway 33 approach area; would be necessary. This could lead to a runway incursion; thinking that the actual runway hold point is closer to the runway; further ahead."
Second reporter narrative
We were taxiing out to Runway 33 with the taxi Instructions; 'Taxi Runway 33 via [Taxiway] A; Cross 25.' We made a left out of our parking spot and quick accomplished the taxi flow and checklist. We cleared left and right and crossed Runway 25. We immediately encountered a red sign '33 - APCH' co-located with a hold short line. I verbalized to the Captain who was taxiing; 'Hold here' He stopped; but seemed confused and wanted to continue to taxi. We briefly discussed what we were looking at and realized we held short in the correct place. The signage and hold short line were in an unexpected place as there was still plenty of taxiway to get to the approach end of 33. The risk for an incursion is high at this place. After reviewing the Jeppesen Airport Diagram for DET; dated 18 Mar 2022; we noticed there was not a Hot Spot or a Note indicating the unexpected issue here. We recommend adding a Hot Spot and a Note on the diagram for this instance. I cannot reiterate enough that the spot is confusing at best; and I am sure people have crossed that line unintentionally in the past. Also; it is worth mentioning that Taxiway J to [Runway] 33 is not a displaced threshold; and in low visibility conditions aircraft may start a takeoff run in the incorrect area.Suggestion: An addition of a Hot Spot and Note on the Airport Diagram. Additionally; the yellow blinking hold short lights would greatly enhance the awareness for pilots during Taxi and low visibility operations.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.