An MD80 on descent declares a passenger medical emergency, and on approach both #1 and #3 compass sy...

Attributes
ACN	507588
Time
Date	200104
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : c90.tracon
State Reference	IL
Altitude	msl single value : 5000
Aircraft 1
Controlling Facilities	tracon : c90.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer only : 22r
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	507588
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical cabin event : passenger illness other anomaly other other spatial deviation
Resolutory Action	controller : provided flight assist flight crew : declared emergency flight crew : overcame equipment problem
Consequence	other other
Supplementary
Problem Areas	Aircraft Passenger Human Performance
Primary Problem	Aircraft

Narrative:

We were having problems during last hour of our flight with both compass system deviating off course. We had to use the magnetic compass at times to slew compasses back on course. We then had a passenger who became ill and fainted. We declared an emergency. As we were nearing ord, we realized we could no longer slew either compass fast enough to stay on proper course. Both compasses at one point were off up to 90 degrees. First officer continued to call off headings using the magnetic compass. Autoplt was not able to engage. We alerted chicago approach of our problem who also noticed a deviation in our heading when we were unable to intercept the localizer for runway 22R. They assisted us until we gained a visual on runway 22R. Callback conversation with reporter revealed the following information: the reporter stated the compass system were acting erratically then when the approach was started, ATC assisted them to the localizer intercept. The reporter said the compass system at this time were 90 degrees in error. The airplane was removed from service and maintenance ferried to the overhaul base. The reporter stated maintenance has not advised of the maintenance action taken and the mode of component failure.

Original NASA ASRS Text

Title: AN MD80 ON DSCNT DECLARES A PAX MEDICAL EMER, AND ON APCH BOTH #1 AND #3 COMPASS SYS FAIL, CAUSE UNKNOWN.

Narrative: WE WERE HAVING PROBS DURING LAST HR OF OUR FLT WITH BOTH COMPASS SYS DEVIATING OFF COURSE. WE HAD TO USE THE MAGNETIC COMPASS AT TIMES TO SLEW COMPASSES BACK ON COURSE. WE THEN HAD A PAX WHO BECAME ILL AND FAINTED. WE DECLARED AN EMER. AS WE WERE NEARING ORD, WE REALIZED WE COULD NO LONGER SLEW EITHER COMPASS FAST ENOUGH TO STAY ON PROPER COURSE. BOTH COMPASSES AT ONE POINT WERE OFF UP TO 90 DEGS. FO CONTINUED TO CALL OFF HDGS USING THE MAGNETIC COMPASS. AUTOPLT WAS NOT ABLE TO ENGAGE. WE ALERTED CHICAGO APCH OF OUR PROB WHO ALSO NOTICED A DEV IN OUR HDG WHEN WE WERE UNABLE TO INTERCEPT THE LOC FOR RWY 22R. THEY ASSISTED US UNTIL WE GAINED A VISUAL ON RWY 22R. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE COMPASS SYS WERE ACTING ERRATICALLY THEN WHEN THE APCH WAS STARTED, ATC ASSISTED THEM TO THE LOC INTERCEPT. THE RPTR SAID THE COMPASS SYS AT THIS TIME WERE 90 DEGS IN ERROR. THE AIRPLANE WAS REMOVED FROM SVC AND MAINT FERRIED TO THE OVERHAUL BASE. THE RPTR STATED MAINT HAS NOT ADVISED OF THE MAINT ACTION TAKEN AND THE MODE OF COMPONENT FAILURE.

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.

An MD80 on descent declares a passenger medical emergency, and on approach both #1 and #3 compass system fail, cause unknown.