Narrative:

A new ramp and run-up area had opened within the prior 2 days at FBO X. Details are not in current AFD for modified taxi diagram. On checking out rental aircraft; I asked for any new taxi instructions/procedures. I was provided with a photocopy of an aerial photograph indicating ramp traffic flow and taxiway entrance to ramp. After aircraft ground check and run-up; I received clearance to taxi to runway 27L at taxiway C. From the ramp/run-up position; there could be seen a direction sign indicating 'charlie' to left and right. I proceed to the right to follow the currently unnamed taxiway; across the threshold of inactive (on the day) runway 5 to intercept taxiway C; to then proceed to runway 27L. At this point; ground clearly instructed me to turn left onto 'charlie' as I was now on 'victor' and needing to proceed on 'delta' to the 'charlie' intersection. I proceed to runway 27L at taxiway C; requesting confirmation prior to crossing 'alpha' that this was my destination; as there was another aircraft taxiing under progressive instructions from ramp. This was confirmed by ground. 1) problem: hand marked ramp/run-up diagram was misleading. Taxi diagram (current) does not indicate new ramp/taxiways. Pilot in command incorrectly assumed route to taxiway current based on taxi diagram direction sign for taxiway C as seen from run-up area given impression 'C' can be accepted in either direction. 2) corrective action: after uneventful flight; returned to FBO and discussed the issue and how it could be avoided by clear; concise diagram until AFD update.

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Original NASA ASRS Text

Title: PA28 pilot is very confused by new ramp construction and diagram provided by FBO. Reporter is unable to locate taxiway C and ends up on D headed Northeast.

Narrative: A new ramp and run-up area had opened within the prior 2 days at FBO X. Details are not in current AFD for modified taxi diagram. On checking out rental aircraft; I asked for any new taxi instructions/procedures. I was provided with a photocopy of an aerial photograph indicating ramp traffic flow and taxiway entrance to ramp. After aircraft ground check and run-up; I received clearance to taxi to Runway 27L at Taxiway C. From the ramp/run-up position; there could be seen a direction sign indicating 'Charlie' to left and right. I proceed to the right to follow the currently unnamed taxiway; across the threshold of inactive (on the day) Runway 5 to intercept Taxiway C; to then proceed to Runway 27L. At this point; Ground clearly instructed me to turn left onto 'Charlie' as I was now on 'Victor' and needing to proceed on 'Delta' to the 'Charlie' intersection. I proceed to Runway 27L at Taxiway C; requesting confirmation prior to crossing 'Alpha' that this was my destination; as there was another aircraft taxiing under progressive instructions from Ramp. This was confirmed by Ground. 1) Problem: Hand marked ramp/run-up diagram was misleading. Taxi diagram (current) does not indicate new ramp/taxiways. Pilot in Command incorrectly assumed route to taxiway current based on taxi diagram direction sign for Taxiway C as seen from run-up area given impression 'C' can be accepted in either direction. 2) Corrective Action: After uneventful flight; returned to FBO and discussed the issue and how it could be avoided by clear; concise diagram until AFD update.

Data retrieved from NASA's ASRS site as of April 2012 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.