Air carrier crew on vectors for the ind runway 23L ILS descended to 2;000 feet; but climb back to 3;...

Attributes
ACN	1313950
Time
Date	201512
Local Time Of Day	0601-1200
Place
Locale Reference	IND.Airport
State Reference	IN
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

On arrival into ind we were cleared for the approach. As pm I read back 'turn right 200 degrees maintain 2000 till established cleared the ILS 23 left approach.' just outside racyr; ATC informed us of a low altitude alert and were told to climb back up to 3000 feet. Once there we were re-cleared for the ILS 23 left approach. No further incidents. I would say that fatigue was the primary culprit. When we read back the clearance it should have seemed an unusual alt to intercept at; as the minimum alt at racyr is 2600 ft. Also when I received the clearance there was chatter on guard 121.5 which could have interfered with hearing our clearance correctly. Better rest; clarification of the clearance and acknowledgement by ATC of the read back.

Original NASA ASRS Text

Title: Air carrier crew on vectors for the IND Runway 23L ILS descended to 2;000 feet; but climb back to 3;000 feet after ATC issued a low altitude alert. Fatigue and a misunderstood descent clearance were factors.

Narrative: On arrival into IND we were cleared for the approach. As PM I read back 'turn right 200 degrees maintain 2000 till established cleared the ILS 23 left approach.' Just outside RACYR; ATC informed us of a low altitude alert and were told to climb back up to 3000 feet. Once there we were re-cleared for the ILS 23 left approach. No further incidents. I would say that fatigue was the primary culprit. When we read back the clearance it should have seemed an unusual alt to intercept at; as the minimum alt at RACYR is 2600 ft. Also when I received the clearance there was chatter on guard 121.5 which could have interfered with hearing our clearance correctly. Better rest; clarification of the clearance and acknowledgement by ATC of the read back.

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.

Air carrier crew on vectors for the ind runway 23L ILS descended to 2;000 feet; but climb back to 3;000 feet after ATC issued a low altitude alert. Fatigue and a misunderstood descent clearance were factors.