Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Aircraft; Human Factors; Procedure
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!
Descending on Korry 3 into LGA and given holding instruction at HOLEY. Holding was given very close to the fix (I believe within 10 miles.) Instructed to hold as published and maintain 11;000 FT. We were descending through approximately 16;000 FT at the time and previously assigned greater than 300 KTS. Began speed reduction to (less than 210 for the hold at HOLEY) and entered hold. On outbound leg ATC instructed us to make a left turn and said we were leaving the protected airspace. We were then given direct to a fix further down the arrival and cleared into LGA. Later discovered that the FMS had 1 1/2 minute legs instead of the published 1 minute legs. Holding was given at the last minute with no warning (no aircraft in front of us were given it.) Looking back we both realized that since we were above 14;000 FT and 300 KTS when the holding was entered; the FMS reverted to 1 1/2 minute legs instead of the 1 minute legs published. We missed this while setting up the hold in the descent to a new altitude assigned and slowing to the assigned holding speed. Once entering the hold we began looking at our fuel situation and possible alternates since our filed alternate was BDL (north of LGA and all the weather that we were holding for.) Needless to say it became a very busy time very quickly and the leg length in the hold was missed.It seems that a lot of holding that is done on line is above 14;000 FT and leg lengths of our choice (1 1/2 minute or 10 mile legs.) In this case it shows that a little extra vigilance is required when entering the hold in the FMS. Since the aircraft was above 14;000 FT it automatically put in 1 1/2 min legs (even though we had 11;000 FT pre selected.)
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.