An embraer 145 flight crew descended below assigned altitude near oxi.

Attributes
ACN	454015
Time
Date	199911
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : oxi.vor
State Reference	IN
Altitude	msl bound lower : 11600 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau.artcc
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	descent : holding
Route In Use	arrival star : oxi 3
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 130 flight time total : 15000 flight time type : 130
ASRS Report	454015
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 5300 flight time type : 500
ASRS Report	453700
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approaching ord on knox arrival at FL230 was given holding at halie intersection, 11000 ft, left turns and hurry down. First officer (PNF) starts programming hold into FMS. At least twice more was told to 'hurry down.' hold in FMS unit displays wrong VOR and radials which brings my head down doublechking arrival in approach plates. We set up VOR to establish position and descending '12000 ft for 11000 ft.' ATC queried as to if we were at 12000 ft. Puzzled, we leveled at 12000 ft and asked if original clearance was 11000 ft. Controller said no, stay at 12000 ft. There was an aircraft at 11000 ft holding at same intersection we saw visually (not knowing he was at 11000 ft but there was never a conflict). Problem arose: first officer wrote down 11000 ft in original instructions and read back 11000 ft. We put 11000 ft in altitude select. Point and repeat 11000 ft. Either we both misinterped original clearance, were given 12000 ft in one of the hurry down clrncs, or 11000 ft is what was given. Contribution: programming FMS kept giving us wrong data. Hold would not arm correctly, causing cockpit distraction and leading to our workload increase. I only have approximately 130 hours in type. Future corrections: I will use VOR backup immediately while other pilot programs FMS. This will give us a quicker redundancy and not as much 'hurry' as we approach the fix.

Original NASA ASRS Text

Title: AN EMBRAER 145 FLC DSNDED BELOW ASSIGNED ALT NEAR OXI.

Narrative: APCHING ORD ON KNOX ARR AT FL230 WAS GIVEN HOLDING AT HALIE INTXN, 11000 FT, L TURNS AND HURRY DOWN. FO (PNF) STARTS PROGRAMMING HOLD INTO FMS. AT LEAST TWICE MORE WAS TOLD TO 'HURRY DOWN.' HOLD IN FMS UNIT DISPLAYS WRONG VOR AND RADIALS WHICH BRINGS MY HEAD DOWN DOUBLECHKING ARR IN APCH PLATES. WE SET UP VOR TO ESTABLISH POS AND DSNDING '12000 FT FOR 11000 FT.' ATC QUERIED AS TO IF WE WERE AT 12000 FT. PUZZLED, WE LEVELED AT 12000 FT AND ASKED IF ORIGINAL CLRNC WAS 11000 FT. CTLR SAID NO, STAY AT 12000 FT. THERE WAS AN ACFT AT 11000 FT HOLDING AT SAME INTXN WE SAW VISUALLY (NOT KNOWING HE WAS AT 11000 FT BUT THERE WAS NEVER A CONFLICT). PROB AROSE: FO WROTE DOWN 11000 FT IN ORIGINAL INSTRUCTIONS AND READ BACK 11000 FT. WE PUT 11000 FT IN ALT SELECT. POINT AND REPEAT 11000 FT. EITHER WE BOTH MISINTERPED ORIGINAL CLRNC, WERE GIVEN 12000 FT IN ONE OF THE HURRY DOWN CLRNCS, OR 11000 FT IS WHAT WAS GIVEN. CONTRIBUTION: PROGRAMMING FMS KEPT GIVING US WRONG DATA. HOLD WOULD NOT ARM CORRECTLY, CAUSING COCKPIT DISTR AND LEADING TO OUR WORKLOAD INCREASE. I ONLY HAVE APPROX 130 HRS IN TYPE. FUTURE CORRECTIONS: I WILL USE VOR BACKUP IMMEDIATELY WHILE OTHER PLT PROGRAMS FMS. THIS WILL GIVE US A QUICKER REDUNDANCY AND NOT AS MUCH 'HURRY' AS WE APCH THE FIX.

Data retrieved from NASA's ASRS site as of July 2007 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.