Pilot descended from assigned altitude without clearance. Pilot deviation. Less than standard separa...

Attributes
ACN	119464
Time
Date	198908
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : asw
State Reference	IN
Altitude	msl bound lower : 4000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other descent other
Route In Use	enroute airway : sbn enroute other
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	119464
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : required legal separation non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Miss Distance	vertical : 600
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Small aircraft a, an arrival to gsh, stopped at 5000' (acknowledged) to maintain sep from small aircraft Y, a pointout from chicago center, gsh sector (still in fort wayne approach airspace) at 4000' (landing in 73). Bases in the area approximately 4900'. Small aircraft X was issued traffic and acknowledged. Small aircraft X called to give pilot report of bases 4900 to 4800'. Mode C confirmed below assigned altitude. Small aircraft X was instructed to climb back to 5000' and did, leaving 4600'. No action taken by small aircraft Y. Pilot was within 15 mi of destination; may have forgotten altitude restriction in eagerness to get to destination.

Original NASA ASRS Text

Title: PLT DESCENDED FROM ASSIGNED ALT WITHOUT CLRNC. PLT DEVIATION. LESS THAN STANDARD SEPARATION.

Narrative: SMA A, AN ARR TO GSH, STOPPED AT 5000' (ACKNOWLEDGED) TO MAINTAIN SEP FROM SMA Y, A POINTOUT FROM CHICAGO CENTER, GSH SECTOR (STILL IN FORT WAYNE APCH AIRSPACE) AT 4000' (LNDG IN 73). BASES IN THE AREA APPROX 4900'. SMA X WAS ISSUED TFC AND ACKNOWLEDGED. SMA X CALLED TO GIVE PLT RPT OF BASES 4900 TO 4800'. MODE C CONFIRMED BELOW ASSIGNED ALT. SMA X WAS INSTRUCTED TO CLB BACK TO 5000' AND DID, LEAVING 4600'. NO ACTION TAKEN BY SMA Y. PLT WAS WITHIN 15 MI OF DEST; MAY HAVE FORGOTTEN ALT RESTRICTION IN EAGERNESS TO GET TO DEST.

Data retrieved from NASA's ASRS site as of August 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.

Pilot descended from assigned altitude without clearance. Pilot deviation. Less than standard separation.