Lgb tower controller reported not detecting that an inbound aircraft had lined up to the departure e...

Narrative:

Aircraft X called 4 miles east of the airport inbound. The trainee gave the pilot instructions to fly southbound along the freeway to make a direct downwind entry. The pilot responded very unconfident; so I gave him the simple instructions to just enter the right downwind for the runway; which he correctly read back. The new radar (fusion) that we are now using causes many radar data tags to completely drop off the radar unexpectedly. In this case; aircraft X's radar data tag dropped off. The confused pilot began flying a heading to the opposite runway than assigned. He advised me that he was lined up for that runway; and without any radar contact on him; he was very difficult to see out the window. Not knowing where he is; and with him telling me that he was lined up for the opposite direction runway; I also had an air carrier landing that I was ready to send around. I instructed aircraft X to climb to 2000 ft and continue westbound to stay clear of any arriving or departing aircraft. At that point; I had him in sight and could see that he was not a factor. The radar tags being dropped off the new fusion radar has been a regular occurrence here. The complexity of rare east traffic operations mixed with inexperienced pilots mixed with an unreliable radar makes for a bad combination. The event explained above should have never been an issue in the first place had our radar been reliable. Fix the issue with fusion.

Original NASA ASRS Text

Title: LGB Tower Controller reported not detecting that an inbound aircraft had lined up to the departure end of the runway due to unreliable radar coverage.

Narrative: Aircraft X called 4 miles east of the airport inbound. The Trainee gave the pilot instructions to fly southbound along the freeway to make a direct downwind entry. The pilot responded very unconfident; so I gave him the simple instructions to just enter the right downwind for the runway; which he correctly read back. The new radar (FUSION) that we are now using causes many radar data tags to COMPLETELY drop off the radar unexpectedly. In this case; Aircraft X's radar data tag dropped off. The confused pilot began flying a heading to the opposite runway than assigned. He advised me that he was lined up for that runway; and without any radar contact on him; he was very difficult to see out the window. Not knowing where he is; and with him telling me that he was lined up for the opposite direction runway; I also had an air carrier landing that I was ready to send around. I instructed Aircraft X to climb to 2000 ft and continue westbound to stay clear of any arriving or departing aircraft. At that point; I had him in sight and could see that he was not a factor. The radar tags being dropped off the new FUSION radar has been a regular occurrence here. The complexity of rare East traffic operations mixed with inexperienced pilots mixed with an unreliable radar makes for a bad combination. The event explained above should have never been an issue in the first place had our radar been reliable. Fix the issue with FUSION.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1478055
Time
Date	201709
Local Time Of Day	0601-1200
Place
Locale Reference	LGB.Tower
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	None
Flight Plan	VFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 4
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance Deviation - Track / Heading All Types

Lgb tower controller reported not detecting that an inbound aircraft had lined up to the departure end of the runway due to unreliable radar coverage.