A BE58 pilot flying IFR abandoned his assigned altitude without permission from mli.

Attributes
ACN	614908
Time
Date	200404
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : boz.ndb
State Reference	IL
Altitude	msl bound lower : 2200 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mli.tracon
Operator	general aviation : personal
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer only : 7 other ndb
Flight Phase	descent : intermediate altitude descent : approach
Route In Use	approach : instrument non precision arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 71 flight time total : 1008 flight time type : 15
ASRS Report	614908
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : issued advisory other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Departed mli to sqi at 5000 ft. ATC assigned vector to intercept localizer back course runway 7 approach at sqi. ATC assigned 3000 ft altitude. Pilot intercepted localizer 12-15 mi from boz. ATC asked if aircraft was established on localizer, and pilot reported it was. ATC cleared pilot for approach. Pilot descended to 2200 ft as published for the segment inbound to the NDB. ATC soon called and said pilot was not cleared for approach and asked if we wanted to cancel IFR. We canceled IFR at that time. Pilot believes he was cleared for the approach but later recognized he descended to 2200 ft outside the 10 NM distance from the NDB. No obstacles were in the area, no corrective action was taken. ATC vectored aircraft to intercept localizer outside the 10 NM limit. Problem could have been avoided if pilot was vectored to intercept within 10 NM. Pilot lacked sufficient situational awareness to recognize the problem. Pilot and ATC disagree on whether or not pilot was cleared for the approach, but point is moot since pilot descended before being on a published segment of approach.

Original NASA ASRS Text

Title: A BE58 PLT FLYING IFR ABANDONED HIS ASSIGNED ALT WITHOUT PERMISSION FROM MLI.

Narrative: DEPARTED MLI TO SQI AT 5000 FT. ATC ASSIGNED VECTOR TO INTERCEPT LOC BACK COURSE RWY 7 APCH AT SQI. ATC ASSIGNED 3000 FT ALT. PLT INTERCEPTED LOC 12-15 MI FROM BOZ. ATC ASKED IF ACFT WAS ESTABLISHED ON LOC, AND PLT RPTED IT WAS. ATC CLRED PLT FOR APCH. PLT DSNDED TO 2200 FT AS PUBLISHED FOR THE SEGMENT INBOUND TO THE NDB. ATC SOON CALLED AND SAID PLT WAS NOT CLRED FOR APCH AND ASKED IF WE WANTED TO CANCEL IFR. WE CANCELED IFR AT THAT TIME. PLT BELIEVES HE WAS CLRED FOR THE APCH BUT LATER RECOGNIZED HE DSNDED TO 2200 FT OUTSIDE THE 10 NM DISTANCE FROM THE NDB. NO OBSTACLES WERE IN THE AREA, NO CORRECTIVE ACTION WAS TAKEN. ATC VECTORED ACFT TO INTERCEPT LOC OUTSIDE THE 10 NM LIMIT. PROB COULD HAVE BEEN AVOIDED IF PLT WAS VECTORED TO INTERCEPT WITHIN 10 NM. PLT LACKED SUFFICIENT SITUATIONAL AWARENESS TO RECOGNIZE THE PROB. PLT AND ATC DISAGREE ON WHETHER OR NOT PLT WAS CLRED FOR THE APCH, BUT POINT IS MOOT SINCE PLT DSNDED BEFORE BEING ON A PUBLISHED SEGMENT OF APCH.

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.