Date: 201902
Local time of day: 0001-0600
Location: PSP.Tower, CA
Flight conditions: Marginal
Weather elements / visibility: Cloudy
Light: Night
Aircraft: Small Transport
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class D PSP
ATC / advisory: Tower PSP
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Contributing factors: Airport; Aircraft; Airspace Structure; Human Factors; Procedure; Weather
Primary problem: Procedure

Narrative: PSP is almost always visual approaches but all day we have been socked in with low ceilings. The only arrivals have been airliners equipped with RNAv RNP approach. The first aircraft to arrive on the VOR-B said they barely got the field in sight at 2300 (the decision height). Following that aircraft I was given [Aircraft X] on the VOR-B. I told SCT what the previous arrival said. [Aircraft X] called me and had the field in sight requesting 31R. I cleared him to land thinking he was on VOR-B. He later asked for 31L due to taxiway closures. I switched him back to 31L cleared to land. I noticed his altitude was low and the Low Altitude (LA) alert went off. I was looking for him with binoculars and gave him a LA alert and verified he had the field in sight still. He was at 600 ft at 4 miles. I was about to issue climb instructions as I looked with binos and pulled up the VOR-B chart. The pilot took a pause to reply and started climbing on his own saying he needed to go around. He was still 3+ miles out and I am CONVINCED he was attempting to land on perhaps a road he perceived to be the runway. It was raining; bases were low; and it was dark. I fully believe he was disoriented. I issued published missed approach (thinking he was VOR-B) and handed him off to SCT with proper coordination. [Aircraft X] then came back on my frequency and said he had the field 'now' and wanted to land. I verified he had 31L in sight and he was issued a landing clearance and landed safely. I had him call me on the phone after he parked. He claimed he broke out of the clouds at 4000 ft and had the field in sight all the way down; he mentioned some kind of new equip in his plane that he was messing with and said he believes he got confused and was attempting to land on something he thought was the runway but 3 miles short. I am thankful he landed safely but I am convinced he would have landed/crashed elsewhere had I not called his LA. SCT verified he was in fact cleared visual; though his tag said VOR-B.SCT change tag to reflect proper approach. Refresher on VOR-B minima (we rarely have days when this approach is used in actual IFR conditions). Refresher on Low Alt alert phraseology and surrounding MVAs.




Synopsis: PSP Tower Controller reported issuing a Low Altitude Alert for an aircraft on a night time visual approach.