Narrative:

Kix to sfo flight. Requested deviation up to 40 mi to go around a very heavy line of thunderstorms. Tokyo refused authority/authorized. I responded that I must deviation somewhere and requested 10-20 mi south of course. Request again refused. I informed tokyo that I was climbing 500 ft and turning right. I also (as per the flight operations manual) turned on exterior lights and broadcast what we were doing on 121.5. We were in contact with another flight 42 NM behind us at FL350. We both saw one another on TCASII. I only got about 5 mi south of course, before finding a hole which we went through, descended and continued on course. These problems continue as far as deviations in the pacific. Tokyo seldom will allow any deviation for WX. My conflicting traffic was a company B747-400 42 mi behind and 2000 ft above me. Someone else may have also been behind me and level at FL330, but outside 42 mi and not TCASII visible. It seems to me that our passenger are at greater risk from flying through a severe thunderstorm than a midair. This whole area of WX deviation, TCASII, etc, needs to be examined. Callback conversation with reporter revealed the following information: this captain was frustrated at trying to get clearance from ARTCC to deviation around some large thunderstorms. He couldn't get clearance so he took it upon himself to deviation as necessary. He did change altitude 500 ft and selected heading to give a clear course through the thunderstorm. He had confidence that TCASII was giving him separation from other aircraft. He was prepared to deviation on his own up to 40 mi but found it only necessary to deviation 20 mi. Captain simply wanted ARTCC to be more responsive to his requests, ARTCC declined all requests. The air carrier he flies for does not give any guidelines of what to do when deviation clrncs are not available.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B747-400 DEVIATES FROM THE AIRWAY TO CIRCUMNAV SOME TSTMS. CLRNC TO DO THIS WAS REQUESTED FROM RJTG BUT CLRNC WAS ALWAYS REFUSED.

Narrative: KIX TO SFO FLT. REQUESTED DEV UP TO 40 MI TO GAR A VERY HVY LINE OF TSTMS. TOKYO REFUSED AUTH. I RESPONDED THAT I MUST DEV SOMEWHERE AND REQUESTED 10-20 MI S OF COURSE. REQUEST AGAIN REFUSED. I INFORMED TOKYO THAT I WAS CLBING 500 FT AND TURNING R. I ALSO (AS PER THE FLT OPS MANUAL) TURNED ON EXTERIOR LIGHTS AND BROADCAST WHAT WE WERE DOING ON 121.5. WE WERE IN CONTACT WITH ANOTHER FLT 42 NM BEHIND US AT FL350. WE BOTH SAW ONE ANOTHER ON TCASII. I ONLY GOT ABOUT 5 MI S OF COURSE, BEFORE FINDING A HOLE WHICH WE WENT THROUGH, DSNDED AND CONTINUED ON COURSE. THESE PROBS CONTINUE AS FAR AS DEVS IN THE PACIFIC. TOKYO SELDOM WILL ALLOW ANY DEV FOR WX. MY CONFLICTING TFC WAS A COMPANY B747-400 42 MI BEHIND AND 2000 FT ABOVE ME. SOMEONE ELSE MAY HAVE ALSO BEEN BEHIND ME AND LEVEL AT FL330, BUT OUTSIDE 42 MI AND NOT TCASII VISIBLE. IT SEEMS TO ME THAT OUR PAX ARE AT GREATER RISK FROM FLYING THROUGH A SEVERE TSTM THAN A MIDAIR. THIS WHOLE AREA OF WX DEV, TCASII, ETC, NEEDS TO BE EXAMINED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS CAPT WAS FRUSTRATED AT TRYING TO GET CLRNC FROM ARTCC TO DEV AROUND SOME LARGE TSTMS. HE COULDN'T GET CLRNC SO HE TOOK IT UPON HIMSELF TO DEV AS NECESSARY. HE DID CHANGE ALT 500 FT AND SELECTED HDG TO GIVE A CLR COURSE THROUGH THE TSTM. HE HAD CONFIDENCE THAT TCASII WAS GIVING HIM SEPARATION FROM OTHER ACFT. HE WAS PREPARED TO DEV ON HIS OWN UP TO 40 MI BUT FOUND IT ONLY NECESSARY TO DEV 20 MI. CAPT SIMPLY WANTED ARTCC TO BE MORE RESPONSIVE TO HIS REQUESTS, ARTCC DECLINED ALL REQUESTS. THE ACR HE FLIES FOR DOES NOT GIVE ANY GUIDELINES OF WHAT TO DO WHEN DEV CLRNCS ARE NOT AVAILABLE.

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.