Widebody transport flight crew declares emergency when denied clearance to deviation WX.

Attributes
ACN	255089
Time
Date	199310
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : hnl
State Reference	CA
Altitude	msl bound lower : 34000 msl bound upper : 34000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : other oceanic enroute : pacific enroute airway : r577
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 230 flight time total : 20000 flight time type : 230
ASRS Report	255089
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 130 flight time total : 8400 flight time type : 130
ASRS Report	255237
Events
Anomaly	inflight encounter : weather non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Weather

Narrative:

Proceeding along R577 to lax we encountered thunderstorms and a broadcast SIGMET across our path. The line of storms extended 20 NM north of course and over 200 NM south. We asked ATC for north deviation (25 NM) and altitude change both on VHF and HF. They denied both requests, offered south deviation. By this time the line filled in, south deviation would have required several hundred mi and endangered our necessary fuel reserve. We declared an emergency for safety of flight and deviated about 27 NM north of course knowing we would have vertical separation of 1000 ft and over 20 NM from R576 traffic. We broadcast our intentions on 121.5, 128.95 and hnl radio HF 132.88. Air carrier X and air carrier Y, wbound on R576, responded. We returned to R577 as soon as possible and notified ATC (hnl radio) at XX15Z. We also notified company dispatch through HF phone patch.

Original NASA ASRS Text

Title: WDB FLC DECLARES EMER WHEN DENIED CLRNC TO DEV WX.

Narrative: PROCEEDING ALONG R577 TO LAX WE ENCOUNTERED TSTMS AND A BROADCAST SIGMET ACROSS OUR PATH. THE LINE OF STORMS EXTENDED 20 NM N OF COURSE AND OVER 200 NM S. WE ASKED ATC FOR N DEV (25 NM) AND ALT CHANGE BOTH ON VHF AND HF. THEY DENIED BOTH REQUESTS, OFFERED S DEV. BY THIS TIME THE LINE FILLED IN, S DEV WOULD HAVE REQUIRED SEVERAL HUNDRED MI AND ENDANGERED OUR NECESSARY FUEL RESERVE. WE DECLARED AN EMER FOR SAFETY OF FLT AND DEVIATED ABOUT 27 NM N OF COURSE KNOWING WE WOULD HAVE VERT SEPARATION OF 1000 FT AND OVER 20 NM FROM R576 TFC. WE BROADCAST OUR INTENTIONS ON 121.5, 128.95 AND HNL RADIO HF 132.88. ACR X AND ACR Y, WBOUND ON R576, RESPONDED. WE RETURNED TO R577 ASAP AND NOTIFIED ATC (HNL RADIO) AT XX15Z. WE ALSO NOTIFIED COMPANY DISPATCH THROUGH HF PHONE PATCH.

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.