Narrative:

I was issued a clearance to taxi to runway 10L via taxiway alpha. Taxiway alpha was marked on the ground as continuing past the intersection for the threshold to 10L. The intersection was marked as juliet. I was unable to recognize that the intersection was the threshold for runway 10L and continued along what was marked as taxiway alpha, which took me past and across the approach end of runway 10L to the threshold to runway 10R. There was no marking indicating that continuing on taxiway alpha would take me into a potentially conflicting area. My clearance did not specify the intersection I was to utilize and there was no hold short instruction given. Following this incident, I spoke with the tower and they advised that they have been aware of the confusing markings and have experienced numerous similar incidents. I was advised that repeated requests have been made by the tower to change and improve the taxiway markings. It also appears that the markings on the ground are not consistent with the airport diagrams. If they were consistent, this incident would not have occurred. Callback conversation with reporter revealed the following information: the reporter stated that he had not used an airport diagram chart prior to his taxi out. When he was abeam of the run up area for runway 10L there was a taxiway sign on the right that identified the area as taxiway 'alpha.' there was another sign to the left that said 'runway 10L.' there was no sign indicating a taxiway juliet, nor any cement markings stating 'juliet' past this 'alpha' or runway sign. The controller advised the pilot of his error after the fact. Reporter claims that the tower said that many incursions have occurred, but added that the local pilots do not have a problem, only the transient pilots. Pilot said he wouldn't make the same mistake again.

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Original NASA ASRS Text

Title: A GA PVT PLT EXPERIENCES A RWY INCURSION AFTER PASSING THE APCH END OF RWY 10L DURING SOME CLRNC AND SIGNAGE CONFUSION WHEN TAXIING OUT FOR DEP AT BOI, ID.

Narrative: I WAS ISSUED A CLRNC TO TAXI TO RWY 10L VIA TXWY ALPHA. TXWY ALPHA WAS MARKED ON THE GND AS CONTINUING PAST THE INTXN FOR THE THRESHOLD TO 10L. THE INTXN WAS MARKED AS JULIET. I WAS UNABLE TO RECOGNIZE THAT THE INTXN WAS THE THRESHOLD FOR RWY 10L AND CONTINUED ALONG WHAT WAS MARKED AS TXWY ALPHA, WHICH TOOK ME PAST AND ACROSS THE APCH END OF RWY 10L TO THE THRESHOLD TO RWY 10R. THERE WAS NO MARKING INDICATING THAT CONTINUING ON TXWY ALPHA WOULD TAKE ME INTO A POTENTIALLY CONFLICTING AREA. MY CLRNC DID NOT SPECIFY THE INTXN I WAS TO UTILIZE AND THERE WAS NO HOLD SHORT INSTRUCTION GIVEN. FOLLOWING THIS INCIDENT, I SPOKE WITH THE TWR AND THEY ADVISED THAT THEY HAVE BEEN AWARE OF THE CONFUSING MARKINGS AND HAVE EXPERIENCED NUMEROUS SIMILAR INCIDENTS. I WAS ADVISED THAT REPEATED REQUESTS HAVE BEEN MADE BY THE TWR TO CHANGE AND IMPROVE THE TXWY MARKINGS. IT ALSO APPEARS THAT THE MARKINGS ON THE GND ARE NOT CONSISTENT WITH THE ARPT DIAGRAMS. IF THEY WERE CONSISTENT, THIS INCIDENT WOULD NOT HAVE OCCURRED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT HE HAD NOT USED AN ARPT DIAGRAM CHART PRIOR TO HIS TAXI OUT. WHEN HE WAS ABEAM OF THE RUN UP AREA FOR RWY 10L THERE WAS A TXWY SIGN ON THE R THAT IDENTIFIED THE AREA AS TXWY 'ALPHA.' THERE WAS ANOTHER SIGN TO THE LEFT THAT SAID 'RWY 10L.' THERE WAS NO SIGN INDICATING A TXWY JULIET, NOR ANY CEMENT MARKINGS STATING 'JULIET' PAST THIS 'ALPHA' OR RWY SIGN. THE CTLR ADVISED THE PLT OF HIS ERROR AFTER THE FACT. RPTR CLAIMS THAT THE TWR SAID THAT MANY INCURSIONS HAVE OCCURRED, BUT ADDED THAT THE LOCAL PLTS DO NOT HAVE A PROB, ONLY THE TRANSIENT PLTS. PLT SAID HE WOULDN'T MAKE THE SAME MISTAKE AGAIN.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.