 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A medium large transport on descent at 15000 ft deviates from assigned course due to loss of EFIS map display caused by a #1 DME failure.
| Attributes | |
| ACN | 471409 |
| Time | |
| Date | 200004 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : bos.airport |
| State Reference | MA |
| Altitude | msl single value : 15000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zbw.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | descent : approach |
| Route In Use | arrival star : gardner 2 |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 6000 flight time type : 200 |
| ASRS Report | 471409 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Independent Detector | other flight crewa other flight crewb |
| Resolutory Action | flight crew : returned to intended or assigned course |
| Consequence | other |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Aircraft |
| Primary Problem | Aircraft |
Narrative:
The captain was flying an autoplt coupled FMS descent into boston, bos via the gardner two arrival with a clearance to cross the bronc intersection at 11000 ft and 250 KTS. Passing between FL180 and 14000 ft we encountered a complete map failure on our navigation display. As we started to identify our location with VOR frequencys, ZBW called us, stating we were north of course and asked if we had read back our crossing restrs. I said 'yes, but we just now encountered a complete map failure,' they immediately gave us a vector, then shortly handed us off to approach control. Our logbook had numerous maintenance carry-overs, one of which was the captain's DME was inoperative. This could have contributed to the map failure since our FMS works off of multi-DME. Additionally, prior to our map failure we did receive a few dead reckoning messages on the multi-purpose control and display unit (mcdu), although they only lasted a brief time on each occurrence.
Original NASA ASRS Text
Title: A MEDIUM LARGE TRANSPORT ON DSCNT AT 15000 FT DEVIATES FROM ASSIGNED COURSE DUE TO LOSS OF EFIS MAP DISPLAY CAUSED BY A #1 DME FAILURE.
Narrative: THE CAPT WAS FLYING AN AUTOPLT COUPLED FMS DSCNT INTO BOSTON, BOS VIA THE GARDNER TWO ARR WITH A CLRNC TO CROSS THE BRONC INTXN AT 11000 FT AND 250 KTS. PASSING BTWN FL180 AND 14000 FT WE ENCOUNTERED A COMPLETE MAP FAILURE ON OUR NAV DISPLAY. AS WE STARTED TO IDENT OUR LOCATION WITH VOR FREQS, ZBW CALLED US, STATING WE WERE N OF COURSE AND ASKED IF WE HAD READ BACK OUR XING RESTRS. I SAID 'YES, BUT WE JUST NOW ENCOUNTERED A COMPLETE MAP FAILURE,' THEY IMMEDIATELY GAVE US A VECTOR, THEN SHORTLY HANDED US OFF TO APCH CTL. OUR LOGBOOK HAD NUMEROUS MAINT CARRY-OVERS, ONE OF WHICH WAS THE CAPT'S DME WAS INOP. THIS COULD HAVE CONTRIBUTED TO THE MAP FAILURE SINCE OUR FMS WORKS OFF OF MULTI-DME. ADDITIONALLY, PRIOR TO OUR MAP FAILURE WE DID RECEIVE A FEW DEAD RECKONING MESSAGES ON THE MULTI-PURPOSE CTL AND DISPLAY UNIT (MCDU), ALTHOUGH THEY ONLY LASTED A BRIEF TIME ON EACH OCCURRENCE.
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.