Narrative:

Our clearance was to an intersection on J121 southwest of pvd 32 mi then direct to calverton VOR. I misread the high altitude chart by reading the DME to a different intersection located very close to the one we were navigating to. We made our turn direct to calverton VOR at about 36 mi over the mistaken intersection mileage, rather than 32 mi. Approach control gave us a heading moments later to 360 degree, no mention of our slightly early turn. The new york high altitude chart is good and usually easy to read but this intersection mileage confusion was very easy happen. The chart should be revised to have the mileage located closer to the intxns. The same map has other airways very poorly labeled for the radials.

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Original NASA ASRS Text

Title: ACR MLG TRACK HDG DEV ENRTE TO ISP.

Narrative: OUR CLRNC WAS TO AN INTXN ON J121 SW OF PVD 32 MI THEN DIRECT TO CALVERTON VOR. I MISREAD THE HIGH ALT CHART BY READING THE DME TO A DIFFERENT INTXN LOCATED VERY CLOSE TO THE ONE WE WERE NAVIGATING TO. WE MADE OUR TURN DIRECT TO CALVERTON VOR AT ABOUT 36 MI OVER THE MISTAKEN INTXN MILEAGE, RATHER THAN 32 MI. APCH CTL GAVE US A HDG MOMENTS LATER TO 360 DEG, NO MENTION OF OUR SLIGHTLY EARLY TURN. THE NEW YORK HIGH ALT CHART IS GOOD AND USUALLY EASY TO READ BUT THIS INTXN MILEAGE CONFUSION WAS VERY EASY HAPPEN. THE CHART SHOULD BE REVISED TO HAVE THE MILEAGE LOCATED CLOSER TO THE INTXNS. THE SAME MAP HAS OTHER AIRWAYS VERY POORLY LABELED FOR THE RADIALS.

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.