The magnetic anomaly departing lga caught an air carrier off course.

Attributes
ACN	277515
Time
Date	199407
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : cri airport : lga
State Reference	NY
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff climbout : initial
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 21000 flight time type : 5040
ASRS Report	277515
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Airport
Air Traffic Incident	other
Situations
Airport	other physical facility

Narrative:

Departed runway 13 at lga, coney climb, in an ahars equipped aircraft. We had mirrors up for standby compass, expecting some error in EFIS due to runway 13. Took off, then EFIS compass erred drastically. Flew the 175 degrees heading by ground reference as we tried to determine which compass was off the least. Reading the standby compass was difficult in the air. The first officer called the approximately heading, I flew the plane. I missed the intercept of cri 243 degrees due to both RMI's being way off. Departure control gave us a turn to 270 degrees for vectors. We advised him that we had compass problems. After about 10 mins after takeoff, the ahars realigned. A stand-by directional gyro or a means to realign the ahars system would have, in my opinion, kept us from going through the cri 243 degrees radial.

Original NASA ASRS Text

Title: THE MAGNETIC ANOMALY DEPARTING LGA CAUGHT AN ACR OFF COURSE.

Narrative: DEPARTED RWY 13 AT LGA, CONEY CLB, IN AN AHARS EQUIPPED ACFT. WE HAD MIRRORS UP FOR STANDBY COMPASS, EXPECTING SOME ERROR IN EFIS DUE TO RWY 13. TOOK OFF, THEN EFIS COMPASS ERRED DRASTICALLY. FLEW THE 175 DEGS HDG BY GND REF AS WE TRIED TO DETERMINE WHICH COMPASS WAS OFF THE LEAST. READING THE STANDBY COMPASS WAS DIFFICULT IN THE AIR. THE FO CALLED THE APPROX HDG, I FLEW THE PLANE. I MISSED THE INTERCEPT OF CRI 243 DEGS DUE TO BOTH RMI'S BEING WAY OFF. DEP CTL GAVE US A TURN TO 270 DEGS FOR VECTORS. WE ADVISED HIM THAT WE HAD COMPASS PROBS. AFTER ABOUT 10 MINS AFTER TKOF, THE AHARS REALIGNED. A STAND-BY DIRECTIONAL GYRO OR A MEANS TO REALIGN THE AHARS SYS WOULD HAVE, IN MY OPINION, KEPT US FROM GOING THROUGH THE CRI 243 DEGS RADIAL.

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.