An RV4 CFI pilot has an near midair collision with a glider at 2500 ft 9 mi west of hio, or.

Attributes
ACN	519297
Time
Date	200107
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : hio.airport
State Reference	OR
Altitude	msl single value : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : hio.tower tracon : ind.tracon
Operator	general aviation : personal
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Aircraft 2
Controlling Facilities	tower : hio.tower
Operator	general aviation : personal
Make Model Name	Sail Plane
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : multi engine pilot : commercial pilot : cfi
Experience	flight time last 90 days : 10 flight time total : 1200 flight time type : 900
ASRS Report	519297
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance Environmental Factor Aircraft ATC Human Performance
Primary Problem	Aircraft

Narrative:

Overtook glider level from behind. Closure speed approximately 90 mph. First observed color markings (on tail) then made out glider shape when it moved. Took immediate corrective action (descent and course correction). Glider profile very hard to see from 6 mi and level. Reported glider activity to hio tower (approximately location and altitude). I am familiar with glider activity in the area and was well clear of their facility. The issue here is how hard they are to see when observing from rear, level and not moving (cruising). The only thing I can think of that might have made it easier to see would be a beacon light.

Original NASA ASRS Text

Title: AN RV4 CFI PLT HAS AN NMAC WITH A GLIDER AT 2500 FT 9 MI W OF HIO, OR.

Narrative: OVERTOOK GLIDER LEVEL FROM BEHIND. CLOSURE SPD APPROX 90 MPH. FIRST OBSERVED COLOR MARKINGS (ON TAIL) THEN MADE OUT GLIDER SHAPE WHEN IT MOVED. TOOK IMMEDIATE CORRECTIVE ACTION (DSCNT AND COURSE CORRECTION). GLIDER PROFILE VERY HARD TO SEE FROM 6 MI AND LEVEL. RPTED GLIDER ACTIVITY TO HIO TWR (APPROX LOCATION AND ALT). I AM FAMILIAR WITH GLIDER ACTIVITY IN THE AREA AND WAS WELL CLR OF THEIR FACILITY. THE ISSUE HERE IS HOW HARD THEY ARE TO SEE WHEN OBSERVING FROM REAR, LEVEL AND NOT MOVING (CRUISING). THE ONLY THING I CAN THINK OF THAT MIGHT HAVE MADE IT EASIER TO SEE WOULD BE A BEACON LIGHT.

Data retrieved from NASA's ASRS site as of July 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.