Narrative:

I cleared aircraft to sfo via pye and the arrival. Then I inadvertently stated maintain FL330 (aircraft was at FL350). I did not catch the readback because aircraft radios were poor. Traffic was quoted at 12 O'clock 5 mi sbound at FL330. At this point aircraft inbound to sfo had not begun descent. He started looking and descended anyways. Controllers are not perfect. Pilots should feel free to question a clearance if it puts them in conflict with another aircraft or even terrain.

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Original NASA ASRS Text

Title: ARTCC RADAR CTLR MISSPOKE ALT FOR ACR X TO MAINTAIN ON THE PYE ARR, THEN POINTED OUT TFC TO THE ACR. THE ACR SAID HE WAS LOOKING AND STARTED A SLOW DSCNT AND SEPARATION WAS LOST WITH ACFT B.

Narrative: I CLRED ACFT TO SFO VIA PYE AND THE ARR. THEN I INADVERTENTLY STATED MAINTAIN FL330 (ACFT WAS AT FL350). I DID NOT CATCH THE READBACK BECAUSE ACFT RADIOS WERE POOR. TFC WAS QUOTED AT 12 O'CLOCK 5 MI SBOUND AT FL330. AT THIS POINT ACFT INBOUND TO SFO HAD NOT BEGUN DSCNT. HE STARTED LOOKING AND DSNDED ANYWAYS. CTLRS ARE NOT PERFECT. PLTS SHOULD FEEL FREE TO QUESTION A CLRNC IF IT PUTS THEM IN CONFLICT WITH ANOTHER ACFT OR EVEN TERRAIN.

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.