Narrative:

This event I consider to be a navigation difficulty. Our RNAV was set up incorrectly for LNAV using the autoplt. After departing lga we received radar vectors to intercept V99 (lga 055 degree radial). Upon selecting LNAV on the RNAV, the aircraft hunted for the radial by turning left then right. Crew reselected heading mode to intercept the radial. ATC then cleared us direct to bayys intersection. Intercept was made using the heading mode again then switched to LNAV. The captain, while trying to dampen the initial aircraft wanderings, selected obs mode on the RNAV without informing the first officer, who was the PF. (A normal RNAV setting would be automatic/leg). Autoplt was engaged when established inbound to bayys. Bayys and seall intxns lie on the same radial (bdr 054 degree radial) 8 mi apart. The 290 degree radial off the groton VOR was being used to backup the RNAV, which also defines seall intersection on the #2 navigation radio. After crossing seall, the aircraft did not track inbound to groton. After noticing the error, crew called ATC for a vector to groton VOR. No further difficulties were experienced. Contributing factors included: crew distraction with ATIS, crew being rushed with an aircraft swap at lga. First officer was inexperienced with RNAV use. Captain was also preoccupied mentally because he had been informed of his base being closed and he being relocated about 1 hour earlier.

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Original NASA ASRS Text

Title: FLC OF ACR MDT ACFT INADVERTENTLY DEVIATED FROM ASSIGNED TRACK DUE TO MISHANDLING THE AUTOPLT FLT DIRECTOR SETTINGS.

Narrative: THIS EVENT I CONSIDER TO BE A NAV DIFFICULTY. OUR RNAV WAS SET UP INCORRECTLY FOR LNAV USING THE AUTOPLT. AFTER DEPARTING LGA WE RECEIVED RADAR VECTORS TO INTERCEPT V99 (LGA 055 DEG RADIAL). UPON SELECTING LNAV ON THE RNAV, THE ACFT HUNTED FOR THE RADIAL BY TURNING L THEN R. CREW RESELECTED HDG MODE TO INTERCEPT THE RADIAL. ATC THEN CLRED US DIRECT TO BAYYS INTXN. INTERCEPT WAS MADE USING THE HDG MODE AGAIN THEN SWITCHED TO LNAV. THE CAPT, WHILE TRYING TO DAMPEN THE INITIAL ACFT WANDERINGS, SELECTED OBS MODE ON THE RNAV WITHOUT INFORMING THE FO, WHO WAS THE PF. (A NORMAL RNAV SETTING WOULD BE AUTO/LEG). AUTOPLT WAS ENGAGED WHEN ESTABLISHED INBOUND TO BAYYS. BAYYS AND SEALL INTXNS LIE ON THE SAME RADIAL (BDR 054 DEG RADIAL) 8 MI APART. THE 290 DEG RADIAL OFF THE GROTON VOR WAS BEING USED TO BACKUP THE RNAV, WHICH ALSO DEFINES SEALL INTXN ON THE #2 NAV RADIO. AFTER XING SEALL, THE ACFT DID NOT TRACK INBOUND TO GROTON. AFTER NOTICING THE ERROR, CREW CALLED ATC FOR A VECTOR TO GROTON VOR. NO FURTHER DIFFICULTIES WERE EXPERIENCED. CONTRIBUTING FACTORS INCLUDED: CREW DISTR WITH ATIS, CREW BEING RUSHED WITH AN ACFT SWAP AT LGA. FO WAS INEXPERIENCED WITH RNAV USE. CAPT WAS ALSO PREOCCUPIED MENTALLY BECAUSE HE HAD BEEN INFORMED OF HIS BASE BEING CLOSED AND HE BEING RELOCATED ABOUT 1 HR EARLIER.

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.