Sct controller described deviation event when he/she mistakenly assumed the 'V' in the data block in...

Attributes
ACN	832963
Time
Date	200904
Local Time Of Day	1201-1800
Place
Locale Reference	POM.VORTAC
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skylane 182/RG Turbo Skylane/RG
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Airway V186.Airway
Flight Plan	IFR
Person 1
Qualification	Air Traffic Control Developmental Air Traffic Control Fully Certified Flight Crew Instrument
Experience	Air Traffic Control Military 3 Air Traffic Control Radar 2 Air Traffic Control Time Certified In Pos 1 (yrs) 1 Flight Crew Total 1800
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Narrative:

On a VFR day; aircraft X checked in 'leaving 5;500 ft for 5;000 ft.' due to the aircraft's position; altitude; and the V ending the aircraft's call sign; I mistook the aircraft to be VFR even though it was on an IFR flight plan. A V in the data block signifies an aircraft is VFR. I instructed aircraft X to 'maintain VFR at or above 3;000 ft' and the pilot replied 'roger' and proceeded to descend. He did not confirm he was on an IFR flight plan. South of pomona; I instructed aircraft X that an 'unrestricted VFR descent into cno was approved.' the pilot said 'you want me below 3;000 ft?' I said 'affirmative VFR descent is approved your discretion.' he replied 'roger' and began a pilot discretionary descent. I realized he was IFR and issued a low altitude alert. He was at 2;300 ft in a 2;500 ft MVA when he initiated the climb. I believe that the call sign ending in a V impaired my situational awareness and led me to believe the pilot was showing VFR in the data block.

Original NASA ASRS Text

Title: SCT controller described deviation event when he/she mistakenly assumed the 'V' in the data block indicated VFR; when in fact the 'V' was part of the aircraft identification; resulting in a altitude assignment below MVA.

Narrative: On a VFR day; Aircraft X checked in 'Leaving 5;500 FT for 5;000 FT.' Due to the aircraft's position; altitude; and the V ending the aircraft's call sign; I mistook the aircraft to be VFR even though it was on an IFR flight plan. A V in the data block signifies an aircraft is VFR. I instructed Aircraft X to 'Maintain VFR at or above 3;000 FT' and the pilot replied 'Roger' and proceeded to descend. He did not confirm he was on an IFR flight plan. South of Pomona; I instructed Aircraft X that an 'unrestricted VFR descent into CNO was approved.' The pilot said 'You want me below 3;000 FT?' I said 'Affirmative VFR descent is approved your discretion.' He replied 'Roger' and began a pilot discretionary descent. I realized he was IFR and issued a low altitude alert. He was at 2;300 FT in a 2;500 FT MVA when he initiated the climb. I believe that the call sign ending in a V impaired my situational awareness and led me to believe the pilot was showing VFR in the data block.

Data retrieved from NASA's ASRS site as of April 2012 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.

Sct controller described deviation event when he/she mistakenly assumed the 'V' in the data block indicated VFR; when in fact the 'V' was part of the aircraft identification; resulting in a altitude assignment below MVA.