Following a hurried descent due to traffic and receipt of a clearance to the ILS the PF first office...

Attributes
ACN	1200264
Time
Date	201409
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Component
Aircraft Component	Autoflight System
Person 1
Function	First Officer
Experience	Flight Crew Last 90 Days 203 Flight Crew Type 400
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Deviation - Altitude Excursion From Assigned Altitude Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Unstabilized Approach

Narrative:

Approaching [our destination] from the south we were given a late descent due to crossing traffic. We were then given multiple course changes and vectors through the localizer in an attempt to lose altitude. We were cleared for the ILS 1L approximately five miles south of the FAF [while] at approximately 4;000 feet MSL. As we continued our descent to [cross the FAF at] 3;000 feet MSL we descended from above to below the glideslope in level change mode and the autopilot captured the localizer. I had approach mode selected but I did not verify that the glideslope or our 3;000 feet MSL altitude was captured [when] I selected zero in the MCP window and the aircraft continued its descent to approximately 2;800 feet MSL at which point I deselected the autopilot and began a climb to 3;000 feet MSL to re-intercept the glideslope at FAF crossing altitude.I should have verbalized setting zero in the MCP window which would have given the pm a chance to cross check that we had not captured the glideslope. We were both busy at the time from configuring the aircraft and communicating with ATC as we tried to descend and slow down.

Original NASA ASRS Text

Title: Following a hurried descent due to traffic and receipt of a clearance to the ILS the PF First Officer of a B737-700 intercepted the localizer but set the MCP altitude to zero prior to confirming GS capture. The FMS remained in Level Change and the flight descended below the glideslope before the flight crew noted the error and corrected.

Narrative: Approaching [our destination] from the south we were given a late descent due to crossing traffic. We were then given multiple course changes and vectors through the Localizer in an attempt to lose altitude. We were cleared for the ILS 1L approximately five miles south of the FAF [while] at approximately 4;000 feet MSL. As we continued our descent to [cross the FAF at] 3;000 feet MSL we descended from above to below the glideslope in Level Change mode and the autopilot captured the Localizer. I had Approach mode selected but I did not verify that the glideslope or our 3;000 feet MSL altitude was captured [when] I selected zero in the MCP window and the aircraft continued its descent to approximately 2;800 feet MSL at which point I deselected the autopilot and began a climb to 3;000 feet MSL to re-intercept the glideslope at FAF crossing altitude.I should have verbalized setting zero in the MCP window which would have given the PM a chance to cross check that we had not captured the glideslope. We were both busy at the time from configuring the aircraft and communicating with ATC as we tried to descend and slow down.

Data retrieved from NASA's ASRS site 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.