BE350 captain reports getting 60 feet low prior to the FAF at hrl with the autopilot flying; which r...

Attributes
ACN	1288231
Time
Date	201508
Local Time Of Day	0601-1200
Place
Locale Reference	HRL.Airport
State Reference	TX
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Super King Air 350
Operating Under FAR Part	Part 135
Flight Phase	Final Approach
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 300 Flight Crew Total 3000 Flight Crew Type 380
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Altitude Overshoot Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

We were flying into hrl repositioning for our passengers. We were cleared the ILS 17R approach. The autopilot (ap) was flying. The chart indicated that we could descend to 1;400 feet 10 miles from the FAF. The FMS had the correct altitude and we put the ap controller into VNAV mode where it descended and captured the 1;400 feet altitude. It was a little late leveling off and we got to maybe 1;340 at the lowest. It then leveled off at 1;400 feet. The tower controller told us that we had a low level alert which showed us at 1;300 feet. The autopilot was already correcting the altitude and no further action was necessary. We got the runway in sight and were cleared to a visual approach for the parallel runway 17L and landed without further incident.

Original NASA ASRS Text

Title: BE350 Captain reports getting 60 feet low prior to the FAF at HRL with the autopilot flying; which results in a low altitude alert from the Tower. The autopilot corrects back to 1;400 feet and the approach is continued to landing.

Narrative: We were flying into HRL repositioning for our passengers. We were cleared the ILS 17R approach. The Autopilot (AP) was flying. The chart indicated that we could descend to 1;400 feet 10 miles from the FAF. The FMS had the correct altitude and we put the AP controller into VNAV mode where it descended and captured the 1;400 feet altitude. It was a little late leveling off and we got to maybe 1;340 at the lowest. It then leveled off at 1;400 feet. The Tower Controller told us that we had a low level alert which showed us at 1;300 feet. The autopilot was already correcting the altitude and no further action was necessary. We got the runway in sight and were cleared to a visual approach for the parallel Runway 17L and landed without further incident.

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.

BE350 captain reports getting 60 feet low prior to the FAF at hrl with the autopilot flying; which results in a low altitude alert from the tower. The autopilot corrects back to 1;400 feet and the approach is continued to landing.