Glideslope failed during ILS approach. Flight crew converted to localizer only approach procedures; ...

Attributes
ACN	1317627
Time
Date	201512
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Small Transport
Operating Under FAR Part	Part 135
Flight Phase	Final Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 6000 Flight Crew Type 2000
Events
Anomaly	Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

We were on vectors for an ILS approach. When given turn to intercept localizer; ATC informed us that the GS was now out of service (OTS) and we were now cleared for the localizer approach instead. In hind sight; at this point I should have discontinued the approach and gone around. This would have allowed my crew to properly brief the localizer approach. I did not do this. Instead; we continued the approach thinking we would be able to easily identify all the step down altitudes. We crossed the first fix at 2;300 feet and then descended all the way to 1;000 feet MDA. By doing this; we missed the 1;640 feet mandatory level-off at the second fix. We broke out of the clouds at 1;200 feet just as we received a low altitude alert from tower. We were then able to see that we were too low and climbed back up to 1;500 feet; which was now clear of clouds; until we were back on a more appropriate visual glide path.

Original NASA ASRS Text

Title: Glideslope failed during ILS approach. Flight crew converted to LOC only approach procedures; but missed a crossing altitude restriction. Tower received a low altitude alert.

Narrative: We were on vectors for an ILS approach. When given turn to intercept LOC; ATC informed us that the GS was now Out of Service (OTS) and we were now cleared for the LOC approach instead. In hind sight; at this point I should have discontinued the approach and gone around. This would have allowed my crew to properly brief the LOC approach. I did not do this. Instead; we continued the approach thinking we would be able to easily identify all the step down altitudes. We crossed the first fix at 2;300 feet and then descended all the way to 1;000 feet MDA. By doing this; we missed the 1;640 feet mandatory level-off at the second fix. We broke out of the clouds at 1;200 feet just as we received a low altitude alert from Tower. We were then able to see that we were too low and climbed back up to 1;500 feet; which was now clear of clouds; until we were back on a more appropriate visual glide path.

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.

Glideslope failed during ILS approach. Flight crew converted to localizer only approach procedures; but missed a crossing altitude restriction. Tower received a low altitude alert.