Narrative:

After departure, we were initially assigned a vector heading of 240 degree, followed shortly thereafter by a heading of 305 degree. Passing approximately 18000 ft, on this heading, we were cleared direct to lrd. I would estimate our position at this time to be approximately 15 mi nnw of the mfe VORTAC. I engaged the flight management system and coupled the unit to the autoplt/flight director system, still proceeding direct to lrd. After a short period of time, I observed that we appeared to be drifting off track to the right, and that the heading had increased to approximately 350 degree. It became evident that the FMS was malfunctioning so I immediately disconnected the flight director and began a turn to the left to return to the assigned direct course to lrd. During the turn, houston center requested our present heading. The first officer replied that we were turning left through 320 degree. The controller then instructed us to turn left to a heading of 260 degree (no reason was given for the heading change). Shortly thereafter, we were given a clearance to proceed direct to lrd. The new sector controller instructed us to call houston center by telephone to discuss 'a possible MOA incursion'. The first officer immediately dialed the number given. He spoke with quality assurance manager at the center. He stated that while we were turning right (during the period the FMS was navigating the aircraft), we had possibly entered the kingsville 1 MOA, which closely paralleled the right side of our course. To guard against further incidents of this nature in the future, we would keep the navigation chart immediately available and closely monitor our position (especially during radar vectors), to insure that we remain well clear of all special use airspace. Be better prepared to switch to secondary navigation sources when it becomes evident that the primary system is malfunctioning (although I did so in this case in a min of time). Regardless of crew position, we will be more assertive in pointing out possible deviations from the planned flight track which could possibly compromise air safety. Supplemental information from acn 189145: I was the first officer PNF and I was talking on the radio with houston center and also backing up the primary navigation system with the #2 navigation radio. When houston center cleared us direct to lrd I noticed our #2 navigation system showed 305 degree direct to lrd. The autoplt along with the primary navigation system turned our aircraft to the right to a heading of 350 degree. I mentioned to the captain that lrd was at 305 degree not 350 degree. We continued heading 350 degree and I mentioned lrd was about our 10 O'clock position. At this time the captain realized the primary navigation system was malfunctioning and turned the aircraft direct towards lrd. The malfunction of our primary navigation system caused our aircraft to change heading of about 50 degree. Even though I stated twice we were off heading maybe I should have been more forceful in the cockpit. On all departures out of hrl, especially when the MOA is hot, all aircraft should be cleared on V17 only, not vectored east of mfe. This leaves very little room for errors.

Related reports:

Google
 

Original NASA ASRS Text

Title: CPR X NON ADHERENCE TO ATC CLRNC UNAUTHORIZED AIRSPACE ENTRY. PLTDEV.

Narrative: AFTER DEP, WE WERE INITIALLY ASSIGNED A VECTOR HDG OF 240 DEG, FOLLOWED SHORTLY THEREAFTER BY A HDG OF 305 DEG. PASSING APPROX 18000 FT, ON THIS HDG, WE WERE CLRED DIRECT TO LRD. I WOULD ESTIMATE OUR POS AT THIS TIME TO BE APPROX 15 MI NNW OF THE MFE VORTAC. I ENGAGED THE FLT MGMNT SYS AND COUPLED THE UNIT TO THE AUTOPLT/FLT DIRECTOR SYS, STILL PROCEEDING DIRECT TO LRD. AFTER A SHORT PERIOD OF TIME, I OBSERVED THAT WE APPEARED TO BE DRIFTING OFF TRACK TO THE R, AND THAT THE HDG HAD INCREASED TO APPROX 350 DEG. IT BECAME EVIDENT THAT THE FMS WAS MALFUNCTIONING SO I IMMEDIATELY DISCONNECTED THE FLT DIRECTOR AND BEGAN A TURN TO THE L TO RETURN TO THE ASSIGNED DIRECT COURSE TO LRD. DURING THE TURN, HOUSTON CENTER REQUESTED OUR PRESENT HDG. THE FO REPLIED THAT WE WERE TURNING L THROUGH 320 DEG. THE CTLR THEN INSTRUCTED US TO TURN L TO A HDG OF 260 DEG (NO REASON WAS GIVEN FOR THE HDG CHANGE). SHORTLY THEREAFTER, WE WERE GIVEN A CLRNC TO PROCEED DIRECT TO LRD. THE NEW SECTOR CTLR INSTRUCTED US TO CALL HOUSTON CENTER BY TELEPHONE TO DISCUSS 'A POSSIBLE MOA INCURSION'. THE FO IMMEDIATELY DIALED THE NUMBER GIVEN. HE SPOKE WITH QUALITY ASSURANCE MGR AT THE CENTER. HE STATED THAT WHILE WE WERE TURNING R (DURING THE PERIOD THE FMS WAS NAVIGATING THE ACFT), WE HAD POSSIBLY ENTERED THE KINGSVILLE 1 MOA, WHICH CLOSELY PARALLELED THE R SIDE OF OUR COURSE. TO GUARD AGAINST FURTHER INCIDENTS OF THIS NATURE IN THE FUTURE, WE WOULD KEEP THE NAV CHART IMMEDIATELY AVAILABLE AND CLOSELY MONITOR OUR POS (ESPECIALLY DURING RADAR VECTORS), TO INSURE THAT WE REMAIN WELL CLR OF ALL SPECIAL USE AIRSPACE. BE BETTER PREPARED TO SWITCH TO SECONDARY NAV SOURCES WHEN IT BECOMES EVIDENT THAT THE PRIMARY SYS IS MALFUNCTIONING (ALTHOUGH I DID SO IN THIS CASE IN A MIN OF TIME). REGARDLESS OF CREW POS, WE WILL BE MORE ASSERTIVE IN POINTING OUT POSSIBLE DEVS FROM THE PLANNED FLT TRACK WHICH COULD POSSIBLY COMPROMISE AIR SAFETY. SUPPLEMENTAL INFO FROM ACN 189145: I WAS THE FO PNF AND I WAS TALKING ON THE RADIO WITH HOUSTON CENTER AND ALSO BACKING UP THE PRIMARY NAV SYS WITH THE #2 NAV RADIO. WHEN HOUSTON CENTER CLRED US DIRECT TO LRD I NOTICED OUR #2 NAV SYS SHOWED 305 DEG DIRECT TO LRD. THE AUTOPLT ALONG WITH THE PRIMARY NAV SYS TURNED OUR ACFT TO THE R TO A HDG OF 350 DEG. I MENTIONED TO THE CAPT THAT LRD WAS AT 305 DEG NOT 350 DEG. WE CONTINUED HDG 350 DEG AND I MENTIONED LRD WAS ABOUT OUR 10 O'CLOCK POS. AT THIS TIME THE CAPT REALIZED THE PRIMARY NAV SYS WAS MALFUNCTIONING AND TURNED THE ACFT DIRECT TOWARDS LRD. THE MALFUNCTION OF OUR PRIMARY NAV SYS CAUSED OUR ACFT TO CHANGE HDG OF ABOUT 50 DEG. EVEN THOUGH I STATED TWICE WE WERE OFF HDG MAYBE I SHOULD HAVE BEEN MORE FORCEFUL IN THE COCKPIT. ON ALL DEPS OUT OF HRL, ESPECIALLY WHEN THE MOA IS HOT, ALL ACFT SHOULD BE CLRED ON V17 ONLY, NOT VECTORED E OF MFE. THIS LEAVES VERY LITTLE ROOM FOR ERRORS.

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.