Air carrier deviates due equipment problem without notifying ATC.

Attributes
ACN	164731
Time
Date	199011
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : hnl
State Reference	HI
Altitude	msl bound lower : 34000 msl bound upper : 34000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
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 : other oceanic enroute : pacific enroute airway : zoa
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 265 flight time total : 5000 flight time type : 750
ASRS Report	164731
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : declared emergency flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Due to pressurization, problem aircraft made a 90 degree turn off of track to 25 mi off center, then direct hnl to join D track at FL330, as per ATC. Flight was over pacific in uncontrolled airspace and deviation was made west/O first notifying hnl radio on high frequency, due to relay time and nature of situation. Flight landed safely in hnl. Decision to return to hnl rather than continue was made based on being west of equal time point. Emergency was not declared per captain as situation was under control. Recommendation: follow proper procedures, when flying international, for turning off track system, and always declare an emergency if deviation is done west/O clearance to cover yourself--it does not cost you anything.

Original NASA ASRS Text

Title: ACR DEVIATES DUE EQUIPMENT PROBLEM WITHOUT NOTIFYING ATC.

Narrative: DUE TO PRESSURIZATION, PROBLEM ACFT MADE A 90 DEG TURN OFF OF TRACK TO 25 MI OFF CENTER, THEN DIRECT HNL TO JOIN D TRACK AT FL330, AS PER ATC. FLT WAS OVER PACIFIC IN UNCONTROLLED AIRSPACE AND DEVIATION WAS MADE W/O FIRST NOTIFYING HNL RADIO ON HIGH FREQ, DUE TO RELAY TIME AND NATURE OF SITUATION. FLT LANDED SAFELY IN HNL. DECISION TO RETURN TO HNL RATHER THAN CONTINUE WAS MADE BASED ON BEING W OF EQUAL TIME POINT. EMER WAS NOT DECLARED PER CAPT AS SITUATION WAS UNDER CTL. RECOMMENDATION: FOLLOW PROPER PROCS, WHEN FLYING INTL, FOR TURNING OFF TRACK SYS, AND ALWAYS DECLARE AN EMER IF DEVIATION IS DONE W/O CLRNC TO COVER YOURSELF--IT DOES NOT COST YOU ANYTHING.

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.