An A320 flight crew; caught up in autoflight manipulation and company mandated airport procedural re...

Attributes
ACN	961669
Time
Date	201107
Local Time Of Day	1801-2400
Place
Locale Reference	LGA.Airport
State Reference	NY
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 7000 Flight Crew Type 2500
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 11800 Flight Crew Type 4800
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT Inflight Event / Encounter Unstabilized Approach

Narrative:

As pilot flying I briefed and prepared for the lda-a at lga. ILS 22 was also briefed and loaded in the secondary route. New york approach said to expect a visual approach to runway 22. On base leg with field at in sight at 2;000 ft we were cleared for a visual approach to 22. At this time I called for the secondary approach to be activated. Outer marker cohop on lda-a is 1;600 ft; outer marker greko on ILS 22 is 1;900 ft. In the transition to the visual (backed up by the ILS 22) I thought I needed to cross greko at 1;600 ft; placing the aircraft high on profile. I selected -1;800 ft/minutes vertical speed to intercept glide slope from above. As the captain cross-checked he realized the aircraft was low on profile. At that time (approximately 1;600 ft) I disconnected the auto pilot; arrested the descent; and maintained level flight until re-intercepting the glide slope (at approximately 1;400 ft); and landed normally. Approach control and lga tower informed us they received a low altitude alert. Spend more time flying the aircraft and less time managing the automation. Had I tracked the lda-a course and flown a visual approach it would have eliminated a high work load in a time compressed situation.

Original NASA ASRS Text

Title: An A320 flight crew; caught up in autoflight manipulation and company mandated airport procedural requirements; descended below the glide slope towards terrain triggering low altitude alerts from both Approach Control and the Tower.

Narrative: As pilot flying I briefed and prepared for the LDA-A at LGA. ILS 22 was also briefed and loaded in the secondary route. New York Approach said to expect a visual approach to Runway 22. On base leg with field at in sight at 2;000 FT we were cleared for a visual approach to 22. At this time I called for the secondary approach to be activated. Outer Marker COHOP on LDA-A is 1;600 FT; Outer Marker GREKO on ILS 22 is 1;900 FT. In the transition to the visual (backed up by the ILS 22) I thought I needed to cross GREKO at 1;600 FT; placing the aircraft high on profile. I selected -1;800 FT/minutes Vertical Speed to intercept glide slope from above. As the Captain cross-checked he realized the aircraft was low on profile. At that time (approximately 1;600 FT) I disconnected the auto pilot; arrested the descent; and maintained level flight until re-intercepting the glide slope (at approximately 1;400 FT); and landed normally. Approach Control and LGA Tower informed us they received a low altitude alert. Spend more time flying the aircraft and less time managing the automation. Had I tracked the LDA-A course and flown a Visual Approach it would have eliminated a high work load in a time compressed situation.

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.

An A320 flight crew; caught up in autoflight manipulation and company mandated airport procedural requirements; descended below the glide slope towards terrain triggering low altitude alerts from both approach control and the tower.