Narrative:

It seems that the new SID/stars for lax have not been added in the database for lax. I could not find the huull 1 STAR in the breakdown. We were assigned the huull 1 tokio transition into lax. While on the STAR past tokio; ATC (la center) queried about our position. I answered that we were on course and ATC alleged that we were not. We checked the flight plan in the FMS and double checked; then checked our position again; and everything checked out. We were on course; as far as our equipment was concerned. ATC gave us a heading; and stated that there may be some interference with the GPS in the area. In a minute or less; he cleared us direct huull. In another minute or so; he gave us a frequency change and; at that time he apologized for the inconvenience; stating that indeed; there was GPS signal jamming in the area. He then apologized again; for the inconvenience. After landing in lax; ground control gave us a phone number to call for lax center; stating there was a possible pilot deviation. I called after we got to the gate; and the la center controller that I talked to stated that we were two miles off course and that he had to file a report; and that we should file [a report]. I advised him of the events as explained above and I told him that as far as we could tell; we did nothing wrong. We concluded the conversation; and about ten minutes later; I got a call from the same gentleman who told me that he listened to the tapes; and also talked to the supervisor on duty at the time; who confirmed that there was GPS jamming at the time; but somehow; he was wrong about it. And he also suggested that it could have been equipment malfunction on our side (the aircraft). I thanked him for the info and that was the end of the conversation. Not sure of what the reason for the deviation was; but we double checked and triple checked and everything in the FMS was entered correctly and looked as it should; however; as far as ATC stated; we were off course. Again; not sure to the cause of this event; so I can't offer any mitigating solutions.

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Original NASA ASRS Text

Title: CRJ200 flight crew reported being informed by ATC that they were off course. They informed the crew that there was reported GPS signal jamming in the area.

Narrative: It seems that the new SID/STARS for LAX have not been added in the database for LAX. I could not find the HUULL 1 STAR in the breakdown. We were assigned the HUULL 1 TOKIO transition into LAX. While on the STAR past TOKIO; ATC (LA Center) queried about our position. I answered that we were on course and ATC alleged that we were not. We checked the flight plan in the FMS and double checked; then checked our position again; and everything checked out. We were on course; as far as our equipment was concerned. ATC gave us a heading; and stated that there may be some interference with the GPS in the area. In a minute or less; he cleared us direct HUULL. In another minute or so; he gave us a frequency change and; at that time he apologized for the inconvenience; stating that indeed; there was GPS signal jamming in the area. He then apologized again; for the inconvenience. After landing in LAX; Ground Control gave us a phone number to call for LAX Center; stating there was a possible pilot deviation. I called after we got to the gate; and the LA Center controller that I talked to stated that we were two miles off course and that he had to file a report; and that we should file [a report]. I advised him of the events as explained above and I told him that as far as we could tell; we did nothing wrong. We concluded the conversation; and about ten minutes later; I got a call from the same gentleman who told me that he listened to the tapes; and also talked to the supervisor on duty at the time; who confirmed that there was GPS jamming at the time; but somehow; he was wrong about it. And he also suggested that it could have been equipment malfunction on our side (the aircraft). I thanked him for the info and that was the end of the conversation. Not sure of what the reason for the deviation was; but we double checked and triple checked and everything in the FMS was entered correctly and looked as it should; however; as far as ATC stated; we were off course. Again; not sure to the cause of this event; so I can't offer any mitigating solutions.

Data retrieved from NASA's ASRS site 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.