Flight crew of CL65 flew wrong heading on departure from ord when procedure from switching from unslaved to slaved directional gyro resulted in heading discrepancy on both pilot displays.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	592242
Time
Date	200308
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	msl single value : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : c90.tracon
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 140 flight time total : 3500 flight time type : 140
ASRS Report	592242
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : clearance non adherence : far other spatial deviation
Independent Detector	other controllera
Resolutory Action	aircraft : equipment problem dissipated controller : issued advisory flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Flight Crew Human Performance Company Airport Aircraft
Primary Problem	Airport

Narrative:

Taking off out of ord, we slaved the directional gyro to runway heading prior to takeoff in directional gyro mode. We took off and we were told to turn to a heading. ATC questioned us as to our heading. We both agreed we were on the correct heading according to our instruments. By looking outside, I knew we weren't on the correct heading and I reslaved my heading indicator to make it correct. The controller handed us off and the problem was corrected. It is our company policy to take off with the directional gyro in directional gyro mode and once level in stabilized unaccelerated flight, we switch back to magnetic mode. We had not leveled off yet so we were still in directional gyro mode to the best of my recollection when the event occurred. After ATC questioned us, I switched to magnetic mode and the directional gyro swung approximately 30 degrees. Once we were in magnetic mode and slewed to the correct heading, the problem was gone and we had no further problems with the aircraft returning to ord.

Original NASA ASRS Text

Title: FLT CREW OF CL65 FLEW WRONG HDG ON DEP FROM ORD WHEN PROC FROM SWITCHING FROM UNSLAVED TO SLAVED DIRECTIONAL GYRO RESULTED IN HDG DISCREPANCY ON BOTH PLT DISPLAYS.

Narrative: TAKING OFF OUT OF ORD, WE SLAVED THE DIRECTIONAL GYRO TO RWY HDG PRIOR TO TKOF IN DIRECTIONAL GYRO MODE. WE TOOK OFF AND WE WERE TOLD TO TURN TO A HDG. ATC QUESTIONED US AS TO OUR HDG. WE BOTH AGREED WE WERE ON THE CORRECT HDG ACCORDING TO OUR INSTS. BY LOOKING OUTSIDE, I KNEW WE WEREN'T ON THE CORRECT HDG AND I RESLAVED MY HDG INDICATOR TO MAKE IT CORRECT. THE CTLR HANDED US OFF AND THE PROB WAS CORRECTED. IT IS OUR COMPANY POLICY TO TAKE OFF WITH THE DIRECTIONAL GYRO IN DIRECTIONAL GYRO MODE AND ONCE LEVEL IN STABILIZED UNACCELERATED FLT, WE SWITCH BACK TO MAGNETIC MODE. WE HAD NOT LEVELED OFF YET SO WE WERE STILL IN DIRECTIONAL GYRO MODE TO THE BEST OF MY RECOLLECTION WHEN THE EVENT OCCURRED. AFTER ATC QUESTIONED US, I SWITCHED TO MAGNETIC MODE AND THE DIRECTIONAL GYRO SWUNG APPROX 30 DEGS. ONCE WE WERE IN MAGNETIC MODE AND SLEWED TO THE CORRECT HDG, THE PROB WAS GONE AND WE HAD NO FURTHER PROBS WITH THE ACFT RETURNING TO ORD.

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.