MD82 descends below crossing altitude because of incorrect altitude setting while in ZAU's airspace.

Attributes
ACN	602091
Time
Date	200312
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : bae.vortac
State Reference	WI
Altitude	msl bound lower : 13000 msl bound upper : 14000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau.artcc tower : pbi.tower
Operator	common carrier : air carrier
Make Model Name	MD-82
Operating Under FAR Part	Part 121
Aircraft 2
Controlling Facilities	artcc : zau.artcc
Operator	common carrier : air carrier
Make Model Name	Do 328 TP (Turboprop)
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	climbout : intermediate altitude descent : approach
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar pilot : multi engine pilot : instrument pilot : commercial pilot : cfi
Experience	controller radar : 23
ASRS Report	602091
Person 2
Affiliation	government : faa
Function	oversight : supervisor
Events
Anomaly	altitude deviation : crossing restriction not met conflict : airborne critical non adherence : clearance non adherence : far non adherence : published procedure
Independent Detector	aircraft equipment : tcas other controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 0
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Mkg V2 sudds mke, crossing sudds at 14000 ft, mke rv mkg eck, etc, climbing to 13000 ft, show aircraft X cleared to cross sudds at 14000 ft. Pilot read clearance back correctly and altimeter correctly. As aircraft a neared sudds I noticed him descending below 13500 ft. I reminded him of his assigned altitude being 14000 ft, no answer. Aircraft B checked on frequency. I assigned a 90 degree turn to heading 180 degrees. I told pilot to expedite turn and expedite climb through 14000 ft then climb to FL230. Went back to aircraft a. Pilot advised he was responding to an RA. Later supervisor spoke to pilot who stated he had misset his altimeter by 1 inch hector pascal.

Original NASA ASRS Text

Title: MD82 DSNDS BELOW XING ALT BECAUSE OF INCORRECT ALT SETTING WHILE IN ZAU'S AIRSPACE.

Narrative: MKG V2 SUDDS MKE, XING SUDDS AT 14000 FT, MKE RV MKG ECK, ETC, CLBING TO 13000 FT, SHOW ACFT X CLRED TO CROSS SUDDS AT 14000 FT. PLT READ CLRNC BACK CORRECTLY AND ALTIMETER CORRECTLY. AS ACFT A NEARED SUDDS I NOTICED HIM DSNDING BELOW 13500 FT. I REMINDED HIM OF HIS ASSIGNED ALT BEING 14000 FT, NO ANSWER. ACFT B CHKED ON FREQ. I ASSIGNED A 90 DEG TURN TO HEADING 180 DEGS. I TOLD PLT TO EXPEDITE TURN AND EXPEDITE CLB THROUGH 14000 FT THEN CLB TO FL230. WENT BACK TO ACFT A. PLT ADVISED HE WAS RESPONDING TO AN RA. LATER SUPVR SPOKE TO PLT WHO STATED HE HAD MISSET HIS ALTIMETER BY 1 INCH HECTOR PASCAL.

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.