Narrative:

Emergency due to moderate turbulence. Encountered continuous moderate turbulence about 100 mi south of champ. Advised HF we needed higher or lower. HF advised ATC could not approve either. Captain advised to get ATC on phone patch. ATC told us we had traffic problem. We saw nothing on TCASII and queried for lower. ATC said unable due to 10 NM separation. We declared an emergency as we felt the ride was approaching severe turbulence. We descended to FL270, proceeded to ZZZ. Aircraft, passenger, and flight crew all fine. Supplemental information from acn 546300: there were no TCASII targets, so we descended straight ahead to FL270.

Google
 

Original NASA ASRS Text

Title: B737 CREW WAS REQUIRED TO USE THE CAPT EMER AUTH TO DSND OUT OF CONTINUOUS MODERATE TURB TO OCCASIONAL SEVERE TURB IN ATLANTIC OCEANIC AIRSPACE.

Narrative: EMER DUE TO MODERATE TURB. ENCOUNTERED CONTINUOUS MODERATE TURB ABOUT 100 MI S OF CHAMP. ADVISED HF WE NEEDED HIGHER OR LOWER. HF ADVISED ATC COULD NOT APPROVE EITHER. CAPT ADVISED TO GET ATC ON PHONE PATCH. ATC TOLD US WE HAD TFC PROB. WE SAW NOTHING ON TCASII AND QUERIED FOR LOWER. ATC SAID UNABLE DUE TO 10 NM SEPARATION. WE DECLARED AN EMER AS WE FELT THE RIDE WAS APCHING SEVERE TURB. WE DSNDED TO FL270, PROCEEDED TO ZZZ. ACFT, PAX, AND FLC ALL FINE. SUPPLEMENTAL INFO FROM ACN 546300: THERE WERE NO TCASII TARGETS, SO WE DSNDED STRAIGHT AHEAD TO FL270.

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.