Night operation encounter small aircraft flying wrong altitude VFR not clear of clouds.

Attributes
ACN	100063
Time
Date	198812
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : swr
State Reference	CA
Altitude	msl bound lower : 12000 msl bound upper : 12000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : atp pilot : commercial
Experience	flight time last 90 days : 70 flight time total : 2500 flight time type : 150
ASRS Report	100063
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : airborne less severe non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Other aircraft VFR below small transport and climbed into small transport's altitude, reason unknown. When other aircraft was sighted, both aircraft were level at same altitude, heading 180 degree, in opp directions. Small transport was IFR flight plan IMC to VFR conditions at time of occurrence. Other aircraft was VFR. Other aircraft did not have legal cloud clearance.

Original NASA ASRS Text

Title: NIGHT OPERATION ENCOUNTER SMA FLYING WRONG ALT VFR NOT CLEAR OF CLOUDS.

Narrative: OTHER ACFT VFR BELOW SMT AND CLBED INTO SMT'S ALT, REASON UNKNOWN. WHEN OTHER ACFT WAS SIGHTED, BOTH ACFT WERE LEVEL AT SAME ALT, HDG 180 DEG, IN OPP DIRECTIONS. SMT WAS IFR FLT PLAN IMC TO VFR CONDITIONS AT TIME OF OCCURRENCE. OTHER ACFT WAS VFR. OTHER ACFT DID NOT HAVE LEGAL CLOUD CLRNC.

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.