Narrative:

I am a student pilot; and was completing my first solo cross-country; flying VFR from palo alto (pao) to castle-merced (mer) and back to pao. When approximately 10 miles north of mount hamilton and descending from 6;500 to 3;500; norcal instructed me to overfly san jose international airport. When I safely passed a departing air carrier; I was instructed to resume normal navigation to pao. I descended to approximately 2;500 ft while approaching nuq airspace. Not realizing that norcal could instruct me to transition nuq airspace; I mistakenly went off-frequency (for approximately 45 seconds) and contacted nuq tower for permission to transition their airspace. I then immediately went back to norcal frequency and was informed that there was an aircraft directly below me; within 100 ft. I realized immediately after changing frequency that I should not have done so. I immediately climbed to 2;500 ft to avoid the other aircraft. Norcal then instructed me to contact pao tower; which I did. I was cleared for straight-in landing on runway 31. The other aircraft; which was slower; was instructed to follow me for a straight-in landing on runway 31.

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Original NASA ASRS Text

Title: Student pilot leaves TRACON frequency to coordinate with Tower; only to come in close proximity to other traffic.

Narrative: I am a student pilot; and was completing my first solo cross-country; flying VFR from Palo Alto (PAO) to Castle-Merced (MER) and back to PAO. When approximately 10 miles north of Mount Hamilton and descending from 6;500 to 3;500; NORCAL instructed me to overfly San Jose International airport. When I safely passed a departing air carrier; I was instructed to resume normal navigation to PAO. I descended to approximately 2;500 FT while approaching NUQ airspace. Not realizing that NORCAL could instruct me to transition NUQ airspace; I mistakenly went off-frequency (for approximately 45 seconds) and contacted NUQ Tower for permission to transition their airspace. I then immediately went back to NORCAL frequency and was informed that there was an aircraft directly below me; within 100 FT. I realized immediately after changing frequency that I should not have done so. I immediately climbed to 2;500 FT to avoid the other aircraft. NORCAL then instructed me to contact PAO tower; which I did. I was cleared for straight-in landing on Runway 31. The other aircraft; which was slower; was instructed to follow me for a straight-in landing on Runway 31.

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.