|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||atc facility : rzc|
|Altitude||msl bound lower : 40000|
msl bound upper : 40000
|Controlling Facilities||artcc : zme|
|Operator||general aviation : corporate|
|Make Model Name||Medium Transport|
|Navigation In Use||Other|
|Flight Phase||cruise other|
|Route In Use||enroute : direct|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 90|
flight time total : 10000
|Function||flight crew : first officer|
|Qualification||pilot : atp|
|Anomaly||aircraft equipment problem : critical|
non adherence : clearance
other spatial deviation
|Independent Detector||other controllera|
|Resolutory Action||controller : issued new clearance|
none taken : unable
|Air Traffic Incident||other|
3/88, I was cleared in a block altitude of FL390 to 410 and was flying at 40000'. The routing was multiple circuits from lit-arg-rzc-lit, etc. Approaching rzc about 30 NM east, center cleared me direct light transport. At the time I was coupled to the sperry FMC and programmed a direct to lit function. The airplane started its turn, at about a 150 degree left turn, and I then got busy with my head in the cockpit sending an EFIS message. My first realization of anything wrong was when center called with, 'I thought you were going direct to little rock.' at the time, I was heading northerly at 40000' and explained to center what had happened and asked for another 360 degree turn to see what the FMC would do when coupled to the right side flight director. The request was granted and the airplane did indeed not capture the 'direct to' leg on the right flight director. After the flight, the FMC vendor rep informed me that this was the fourth occurrence known with the new software program. Callback conversation with reporter revealed the following: reporter says he works with the FMC vendor daily and they are well aware of the problem and are working on it. Do not think ASRS could add anything to what is being done.
Original NASA ASRS Text
Title: FLT CREW OF CPR MDT HAD PROBLEM WITH COURSE CAPTURE OF FMC DURING PRODUCTION TEST FLT. MANUFACTURER SAID THIS WAS THE FOURTH OCCURRENCE USING THIS PARTICULAR PROGRAM.
Narrative: 3/88, I WAS CLRED IN A BLOCK ALT OF FL390 TO 410 AND WAS FLYING AT 40000'. THE ROUTING WAS MULTIPLE CIRCUITS FROM LIT-ARG-RZC-LIT, ETC. APCHING RZC ABOUT 30 NM E, CENTER CLRED ME DIRECT LTT. AT THE TIME I WAS COUPLED TO THE SPERRY FMC AND PROGRAMMED A DIRECT TO LIT FUNCTION. THE AIRPLANE STARTED ITS TURN, AT ABOUT A 150 DEG LEFT TURN, AND I THEN GOT BUSY WITH MY HEAD IN THE COCKPIT SENDING AN EFIS MESSAGE. MY FIRST REALIZATION OF ANYTHING WRONG WAS WHEN CENTER CALLED WITH, 'I THOUGHT YOU WERE GOING DIRECT TO LITTLE ROCK.' AT THE TIME, I WAS HDG NORTHERLY AT 40000' AND EXPLAINED TO CENTER WHAT HAD HAPPENED AND ASKED FOR ANOTHER 360 DEG TURN TO SEE WHAT THE FMC WOULD DO WHEN COUPLED TO THE RIGHT SIDE FLT DIRECTOR. THE REQUEST WAS GRANTED AND THE AIRPLANE DID INDEED NOT CAPTURE THE 'DIRECT TO' LEG ON THE RIGHT FLT DIRECTOR. AFTER THE FLT, THE FMC VENDOR REP INFORMED ME THAT THIS WAS THE FOURTH OCCURRENCE KNOWN WITH THE NEW SOFTWARE PROGRAM. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR SAYS HE WORKS WITH THE FMC VENDOR DAILY AND THEY ARE WELL AWARE OF THE PROBLEM AND ARE WORKING ON IT. DO NOT THINK ASRS COULD ADD ANYTHING TO WHAT IS BEING DONE.
Data retrieved from NASA's ASRS site as of August 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.