Narrative:

[Recently] lga began implementing RNAV departures. We were assigned the stbnz 2 to biggy. We noticed that the FMS duplicated the stbnz waypoint in the middle of the procedure. It showed 0.0 NM between the duplicate points. This seemed strange; and I would have normally deleted the duplicate waypoint; but there is a prohibition in the pilot handbook against manually editing waypoints in an RNAV procedure. The airplane flew to stbnz; failed to anticipate the turn to munnz; and then went into roll mode. We switched to heading and started turning immediately but there was no way to avoid overshooting the course from stbnz to munnz. This procedure is coded incorrectly in the database. It was southwest NZ5.2 with the DB dated 23 sep to 20 oct 2010. I took pictures of the 3 pages of 'procedure review' that show the coding error and emailed them. After investigating further; I discovered that there is a similar coding error (duplicate waypoints) in 3 of the 5 new RNAV departures for lga. I also tried loading the new RNAV departures for phl but did not see any errors on these procedures. Furthermore; I spoke to another captain and he was able to duplicate it in another airplane; so based on this; I believe this is a fleet wide problem. My recommendations would be 1) a memo stating no RNAV departures out of lga and 2) have dispatch file all flights out of lga as unable RNAV departures until honeywell fixes the coding of these procedures.

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Original NASA ASRS Text

Title: An EMB145's LGA STBNZ TWO RNAV DEPARTURE FMS database contains two STBNZ waypoints at 0 DME distance which caused the aircraft to transition from the FMS procedure to a roll mode. The crew selected the heading mode after overshooting the BIGGY transition.

Narrative: [Recently] LGA began implementing RNAV departures. We were assigned the STBNZ 2 to BIGGY. We noticed that the FMS duplicated the STBNZ waypoint in the middle of the procedure. It showed 0.0 NM between the duplicate points. This seemed strange; and I would have normally deleted the duplicate waypoint; but there is a prohibition in the Pilot Handbook against manually editing waypoints in an RNAV procedure. The airplane flew to STBNZ; failed to anticipate the turn to MUNNZ; and then went into roll mode. We switched to HDG and started turning immediately but there was no way to avoid overshooting the course from STBNZ to MUNNZ. This procedure is coded incorrectly in the database. It was SW NZ5.2 with the DB dated 23 SEP to 20 OCT 2010. I took pictures of the 3 pages of 'Procedure Review' that show the coding error and emailed them. After investigating further; I discovered that there is a similar coding error (duplicate waypoints) in 3 of the 5 new RNAV departures for LGA. I also tried loading the new RNAV departures for PHL but did not see any errors on these procedures. Furthermore; I spoke to another Captain and he was able to duplicate it in another airplane; so based on this; I believe this is a fleet wide problem. My recommendations would be 1) a memo stating no RNAV departures out of LGA and 2) have dispatch file all flights out of LGA as unable RNAV departures until Honeywell fixes the coding of these procedures.

Data retrieved from NASA's ASRS site as of April 2012 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.