Narrative:

Descending via korry three arrival enroute lga. Due to enroute and terminal weather; instructions were issued to hold as published at holey. FMS was programmed by the PF and verified by the pm with inbound course 058 degrees and 1 and 1/2 minute legs and assigned efc while descending through approximately 15;000 ft. Descent clearance was subsequently amended to level at 11;000 ft. While initiating turn to the inbound course; ATC issued instructions to turn inbound because we were out of the holding airspace. No amplifying information was provided and shortly thereafter clearance to exit holding and proceed inbound to lga was issued. Per ATC; we exited the established holding airspace. No indications were present to indicate separation minima were violated; nor did ATC state such. However; this event could have resulted in such an incursion under other circumstances. After some head scratching; we determined that what probably occurred was since the FMS was programmed at approximately 15;000 ft; leg length defaulted to 1 and 1/2 minutes. But at the subsequently assigned 11;000 ft holding altitude; the airspace was structured around a 1 minute holding pattern. Despite leveling at 11;000 ft; the FMS did not automatically adjust the leg length. This was our only plausible explanation as to why we were reportedly leaving the holding airspace. Kind of an odd set of circumstances; but lesson learned!

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Original NASA ASRS Text

Title: CRJ700 flight crew is issued holding instructions descending through 16;000 FT for an 11;000 foot hold as depicted on the arrival but does not note that the FMC has defaulted to one and a half minute legs when one minute legs are required below 14;000 FT. ATC takes note and issues a revised clearance.

Narrative: Descending via Korry Three Arrival enroute LGA. Due to enroute and terminal weather; instructions were issued to hold as published at HOLEY. FMS was programmed by the PF and verified by the PM with inbound course 058 degrees and 1 and 1/2 minute legs and assigned EFC while descending through approximately 15;000 FT. Descent clearance was subsequently amended to level at 11;000 FT. While initiating turn to the inbound course; ATC issued instructions to turn inbound because we were out of the holding airspace. No amplifying information was provided and shortly thereafter clearance to exit holding and proceed inbound to LGA was issued. Per ATC; we exited the established holding airspace. No indications were present to indicate separation minima were violated; nor did ATC state such. However; this event could have resulted in such an incursion under other circumstances. After some head scratching; we determined that what probably occurred was since the FMS was programmed at approximately 15;000 FT; leg length defaulted to 1 and 1/2 minutes. But at the subsequently assigned 11;000 FT holding altitude; the airspace was structured around a 1 minute holding pattern. Despite leveling at 11;000 FT; the FMS did not automatically adjust the leg length. This was our only plausible explanation as to why we were reportedly leaving the holding airspace. Kind of an odd set of circumstances; but lesson learned!

Data retrieved from NASA's ASRS site as of July 2013 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.