An air carrier captain reported that his FMS failed while on the phl bunts 1 arrival and because raw...

Attributes
ACN	912514
Time
Date	201010
Local Time Of Day	1801-2400
Place
Locale Reference	ZOB.ARTCC
State Reference	OH
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR BUNTS 1
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 180 Flight Crew Total 13000 Flight Crew Type 6000
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

On the bunts 1 arrival to phl. Clearance was given to descend from 330 to cross 45 west har at 250. Immediately after that we had a FMS map failure. I didn't have raw data to back up the arrival so I started the descent immediately to make the restriction. Aircraft went into heading hold and while I flew the first officer began the process of getting our FMS back. We were probably in heading hold for about a minute and during that time the aircraft drifted slightly right of course. ATC made no comment about the deviation. My first officer also pulled up the raw data after we had regained the FMS and proceeded back to the course. In retrospect; I should have had raw data more readily accessible which would have cut down on the time the aircraft was in heading hold and limited the deviation.

Original NASA ASRS Text

Title: An air carrier Captain reported that his FMS failed while on the PHL BUNTS 1 Arrival and because raw data was not immediately available a slight track deviation occurred.

Narrative: On the Bunts 1 arrival to PHL. Clearance was given to descend from 330 to cross 45 west HAR at 250. Immediately after that we had a FMS map failure. I didn't have raw data to back up the arrival so I started the descent immediately to make the restriction. Aircraft went into HDG hold and while I flew the First Officer began the process of getting our FMS back. We were probably in HDG hold for about a minute and during that time the aircraft drifted slightly right of course. ATC made no comment about the deviation. My First Officer also pulled up the raw data after we had regained the FMS and proceeded back to the course. In retrospect; I should have had raw data more readily accessible which would have cut down on the time the aircraft was in heading hold and limited the deviation.

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.

An air carrier captain reported that his FMS failed while on the phl bunts 1 arrival and because raw data was not immediately available a slight track deviation occurred.