Heading track deviation due to thunderstorm activity on overwater operation.

Attributes
ACN	229602
Time
Date	199212
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : zoa
State Reference	CA
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : pacific enroute : other oceanic
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 : 175 flight time total : 9000 flight time type : 1600
ASRS Report	229602
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : clearance non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

On north flew track from hnl-nrt FL350. IMC in stratus layer. Radar painted 2 thunderstorm cells on course line approximately 75 NM ahead. They showed contour at that distance, wind from south approximately 35 KTS. Requested deviation up to 20 NM south of course account WX. Denied! Requested deviation north up to 40 NM. Denied! Thunderstorm cells now less than 20 NM ahead. Called 'pan pan pan' went around cells to north. Did not exceed 20 NM. Once around cells, returned to track expeditiously. Reported back on track. The safety of my aircraft dictated that I take this deviation.

Original NASA ASRS Text

Title: HDG TRACK DEV DUE TO TSTM ACTIVITY ON OVERWATER OP.

Narrative: ON N FLEW TRACK FROM HNL-NRT FL350. IMC IN STRATUS LAYER. RADAR PAINTED 2 TSTM CELLS ON COURSE LINE APPROX 75 NM AHEAD. THEY SHOWED CONTOUR AT THAT DISTANCE, WIND FROM S APPROX 35 KTS. REQUESTED DEV UP TO 20 NM S OF COURSE ACCOUNT WX. DENIED! REQUESTED DEV N UP TO 40 NM. DENIED! TSTM CELLS NOW LESS THAN 20 NM AHEAD. CALLED 'PAN PAN PAN' WENT AROUND CELLS TO N. DID NOT EXCEED 20 NM. ONCE AROUND CELLS, RETURNED TO TRACK EXPEDITIOUSLY. RPTED BACK ON TRACK. THE SAFETY OF MY ACFT DICTATED THAT I TAKE THIS DEV.

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.