Narrative:

I departed psp on runway 31R on an IFR flight plan. My clearance included: cathedral 9; join V370; tnp; then as filed. On previous departures I have generally been vectored and have not flown the entire departure. In this instance I flew to psp and turned on V370 toward tnp. Immediately ATC asked me to confirm I was flying the CATH9 SID. I replied that I thought I was flying my clearance. ATC courteously explained that I was not and that in IMC the terrain to the east might be a factor. I requested a visual climb and the request was granted. I believe that my previous experience of being vectored directly to V370 influenced how I read and understood the departure route description on the chart. With the clearance including the phrase 'join V370' I made an erroneous assumption that I was not to fly the procedure after psp. In reading the departure route description afterward it is clear that I was mistaken; but it seems that the departure procedure and clearance could be communicated better somehow. There was no other traffic at the time so the departure controller and I briefly discussed the miscommunication. He told me I was not alone in my mistake and that many airline pilots had made the same assumption. Clearly the mistake was mine alone and I accept full responsibility. In light of the fact that others seem to make the same mistake; I wonder if there is a better way of communicating the clearance to emphasize the entire departure procedure must be flown.

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Original NASA ASRS Text

Title: A light aircraft pilot departing PSP on the CATHEDRAL 9 SID deviated from the charted procedure and felt there could be some improvements in how the clearance was given to avoid the same problem in the future.

Narrative: I departed PSP on Runway 31R on an IFR flight plan. My clearance included: CATHEDRAL 9; join V370; TNP; then as filed. On previous departures I have generally been vectored and have not flown the entire departure. In this instance I flew to PSP and turned on V370 toward TNP. Immediately ATC asked me to confirm I was flying the CATH9 SID. I replied that I thought I was flying my clearance. ATC courteously explained that I was not and that in IMC the terrain to the east might be a factor. I requested a visual climb and the request was granted. I believe that my previous experience of being vectored directly to V370 influenced how I read and understood the departure route description on the chart. With the clearance including the phrase 'join V370' I made an erroneous assumption that I was not to fly the procedure after PSP. In reading the departure route description afterward it is clear that I was mistaken; but it seems that the departure procedure and clearance could be communicated better somehow. There was no other traffic at the time so the Departure Controller and I briefly discussed the miscommunication. He told me I was not alone in my mistake and that many airline pilots had made the same assumption. Clearly the mistake was mine alone and I accept full responsibility. In light of the fact that others seem to make the same mistake; I wonder if there is a better way of communicating the clearance to emphasize the entire departure procedure must be flown.

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.