Date: 201207
Local time of day: 1801-2400
Location: SUA.Tower, FL
Flight conditions: VMC
Weather elements / visibility: 7
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Final Approach
Airspace: Class D SUA
ATC / advisory: Tower SUA
Aircraft component: Aero Charts
Component problem: Design
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Human factors: Human-Machine Interface; Confusion; Situational Awareness
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Airport; Chart Or Publication; Human Factors
Primary problem: Chart Or Publication

Narrative: Approaching SUA from the North I was cleared to begin my approach for Runway 12; and asked to report a left base. I had printed out the Airport Diagram from the FAA's digital terminal procedures publication; and used this diagram to locate what I believed was Runway 12 on the Airport Diagram. During the approach; I could sense that something was wrong with my approach. The wind was reported to be 120/8 (or thereabouts - I know it was reported as straight down the runway); and I could clearly see and feel a left crosswind. Furthermore; my DG was not showing 12; but closer to 15. I attempted to compare this to the wet compass (thinking my DG had precessed); but was also concentrating on making my approach. Unable to reconcile this reading; I attempted to verify that the runway I was looking at was labeled '12' on the chart; by comparing it to the printed diagram.The Controller allowed me to continue my descent and; before reaching an unsafe altitude; asked me to report my heading. I reported 15; and he told me I was flying an approach to 16 and instructed me to go around. I made a safe go around; and carried out an uneventful stop and go on runway 12; departing to the north.This is the first mistake of this kind I have made and; so; have spent some time analyzing the causes. On reflection; I believe the chart to SUA is very confusing. When the PDF is printed; the ELEV for Runway 16 is printed very close to the arrival end of Runway 16; and its value is 12. Furthermore; the runway number; 16; is printed on a dark grey background; making it very difficult to read in flight. To add to this; the arrival end of runway 7 is marked ELEV 16. So a quick look at the chart told me I was approaching 12. The electronic version of the Airport Diagram looks much clearer - I would encourage you to print the chart and examine the printed copy as this is what will actually be in the cockpit.From a human factors perspective; I think I suffered a little from tunnel vision. My first mistake was the worst mistake. Once I had misidentified the runway on the chart; I never really revisited that decision despite the many clues I had that something was awry. Although I knew something was not right; I continued to fly the approach. I should have simply admitted that I was confused and requested input from the tower. However; my ability to read maps (I was sure of my position relative to the airport and was; in fact; correct - the only issue was my mislabeling of the runway) overrode my trust in the instruments. On a positive note; I am very appreciative of the way the controller handled the situation. I am sure he knew instantly what I was doing and the mistake I had made; but allowed me to carry out more of the maneuver while maintaining adequate separation with other traffic so I could learn the lesson in a safe way. Had they told me at the very beginning of the approach; I do not think I would have learned as much.




Synopsis: Confused by the NACO Airport Diagram's format for display of Runway numbers and TDZ elevations; the pilot of a C172 made his initial approach to land at SUA to Runway 16 vice 12 as cleared. ATC alerted him and directed a go around after which he returned to land safely on Runway 12.