Hang glider pilot reported a near-mid-air-collision with a general aviation aircraft.

Attributes
ACN	1492712
Time
Date	201710
Local Time Of Day	1201-1800
Place
Locale Reference	SBD.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Ultralight
Operating Under FAR Part	Part 103
Flight Phase	Climb
Route In Use	None
Flight Plan	None
Aircraft 2
Make Model Name	Cessna Single Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Visual Approach
Person 1
Function	Single Pilot
Qualification	Flight Crew Sport / Recreational
Experience	Flight Crew Last 90 Days 63 Flight Crew Total 2000 Flight Crew Type 2000
Events
Anomaly	Conflict NMAC Deviation - Procedural FAR
Miss Distance	Horizontal 0 Vertical 100

Narrative:

I was mid-way through my 4th revolution while turning in a weak thermal when I heard the distinct turbine whine of a light aircraft magneto. I looked up and behind me and observed a cessna 172 or 152 approximately 100 ft above my hang glider on glide with its propeller wind milling. It appeared to be on a 160-degree course heading and proceeded away from me uninterrupted. Because I was in direct sunlight and the large holographic reflective surfaces on my leading edges would have been easily visible for 5 miles I have to assume the pilot was curious and glided toward me intentionally. Obviously; I don't know whether the pilot thought he was seeing a mylar party balloon or knew it was a hang glider but in any event the incursion looked intentional and at 100 ft proximity was unsafe.

Original NASA ASRS Text

Title: Hang glider pilot reported a near-mid-air-collision with a general aviation aircraft.

Narrative: I was mid-way through my 4th revolution while turning in a weak thermal when I heard the distinct turbine whine of a light aircraft magneto. I looked up and behind me and observed a Cessna 172 or 152 approximately 100 FT above my hang glider on glide with its propeller wind milling. It appeared to be on a 160-degree course heading and proceeded away from me uninterrupted. Because I was in direct sunlight and the large holographic reflective surfaces on my leading edges would have been easily visible for 5 miles I have to assume the pilot was curious and glided toward me intentionally. Obviously; I don't know whether the pilot thought he was seeing a Mylar party balloon or knew it was a hang glider but in any event the incursion looked intentional and at 100 FT proximity was unsafe.

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.