MD80 captain reports att and heading comparator lights illuminating at FL310; the decision was made ...

Narrative:

Shortly after crossing into us airspace; instrument comparator lights came on. Displayed on the first officer side were steady; 'att' and 'heading' lights. On the captain side were flashing 'att' and 'heading' lights. The course display window on the captain's side showed rolling numbers. The captain's pfd displayed only frozen flight director bars with a red 'att' message; and his nd was blank except for a red 'heading' message. A popped 'VHF navigation' circuit breaker in the overhead panel was also discovered. We consulted the QRH; the dispatcher and part I. A decision to divert was made; for reasons of weather; nearness and availability of customs service. The aircraft was landed at about 133;000 pounds landing weight; using overweight landing procedures from the QRH and the flight manual. An overweight landing inspection was accomplished prior to the next leg. Maintenance discussions on the ground mentioned a loosely secured navigation box had been discovered. Flight then proceeded to destination without incident.

Original NASA ASRS Text

Title: MD80 Captain reports ATT and HDG comparator lights illuminating at FL310; the decision was made to divert for repairs. After overweight landing inspection Maintenance discoverd component loosely secured in rack; likely causing the problem.

Narrative: Shortly after crossing into U.S. airspace; instrument comparator lights came on. Displayed on the First Officer side were steady; 'ATT' and 'HDG' lights. On the Captain side were flashing 'ATT' and 'HDG' lights. The course display window on the Captain's side showed rolling numbers. The Captain's PFD displayed only frozen flight director bars with a red 'ATT' message; and his ND was blank except for a red 'HDG' message. A popped 'VHF NAV' circuit breaker in the overhead panel was also discovered. We consulted the QRH; the Dispatcher and Part I. A decision to divert was made; for reasons of weather; nearness and availability of customs service. The aircraft was landed at about 133;000 LBS landing weight; using overweight landing procedures from the QRH and the flight manual. An overweight landing inspection was accomplished prior to the next leg. Maintenance discussions on the ground mentioned a loosely secured navigation box had been discovered. Flight then proceeded to destination without incident.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	885122
Time
Date	201004
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Aircraft 1
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Component
Aircraft Component	Navigational Equipment and Processing
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

MD80 captain reports att and heading comparator lights illuminating at FL310; the decision was made to divert for repairs. After overweight landing inspection maintenance discoverd component loosely secured in rack; likely causing the problem.