Air data computer failure causes aircraft to deviate 9 mi from planned track.

Attributes
ACN	317017
Time
Date	199509
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mkk
State Reference	HI
Altitude	msl bound lower : 32000 msl bound upper : 34000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhn
Operator	common carrier : air carrier
Make Model Name	DC-8 70
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : flight engineer pilot : cfi
Experience	flight time last 90 days : 150 flight time total : 13500 flight time type : 3500
ASRS Report	317017
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was the PF. During takeoff at hnl, all my pitot static instruments suddenly quit along with most of my EFIS equipment due to the interrelation between them. Due to our heavy takeoff weight and proximity to V1, the captain said to continue the takeoff. WX was also excellent. Found I had no yaw damper or autoplt. The captain decided at this point to fly the aircraft while the flight engineer and I worked the problem. We found the #2 air data computer failed and I could crossover the captain's flight instruments to my side and regain everything. I was again flying and while tracking out to our first coast out navigation chkpoint 'cluts,' the autoplt did not engage in the INS mode as we thought due to our repeated switching back and forth of instruments while trying to determine if we could accept this aircraft for the overwater crossing to ont. Nearing cluts, ATC advised us that we were 9 mi west of cluts intersection which we quickly corrected. After an unusual situation like this, each pilot should completely review his instrumentation and mode selectors and then review and backup the other pilot in this manner. Company procedures and checklists should be written to make mention of this.

Original NASA ASRS Text

Title: AIR DATA COMPUTER FAILURE CAUSES ACFT TO DEVIATE 9 MI FROM PLANNED TRACK.

Narrative: I WAS THE PF. DURING TKOF AT HNL, ALL MY PITOT STATIC INSTS SUDDENLY QUIT ALONG WITH MOST OF MY EFIS EQUIP DUE TO THE INTERRELATION BTWN THEM. DUE TO OUR HVY TKOF WT AND PROX TO V1, THE CAPT SAID TO CONTINUE THE TKOF. WX WAS ALSO EXCELLENT. FOUND I HAD NO YAW DAMPER OR AUTOPLT. THE CAPT DECIDED AT THIS POINT TO FLY THE ACFT WHILE THE FE AND I WORKED THE PROB. WE FOUND THE #2 AIR DATA COMPUTER FAILED AND I COULD CROSSOVER THE CAPT'S FLT INSTS TO MY SIDE AND REGAIN EVERYTHING. I WAS AGAIN FLYING AND WHILE TRACKING OUT TO OUR FIRST COAST OUT NAV CHKPOINT 'CLUTS,' THE AUTOPLT DID NOT ENGAGE IN THE INS MODE AS WE THOUGHT DUE TO OUR REPEATED SWITCHING BACK AND FORTH OF INSTS WHILE TRYING TO DETERMINE IF WE COULD ACCEPT THIS ACFT FOR THE OVERWATER XING TO ONT. NEARING CLUTS, ATC ADVISED US THAT WE WERE 9 MI W OF CLUTS INTXN WHICH WE QUICKLY CORRECTED. AFTER AN UNUSUAL SIT LIKE THIS, EACH PLT SHOULD COMPLETELY REVIEW HIS INSTRUMENTATION AND MODE SELECTORS AND THEN REVIEW AND BACKUP THE OTHER PLT IN THIS MANNER. COMPANY PROCS AND CHKLISTS SHOULD BE WRITTEN TO MAKE MENTION OF THIS.

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.