PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 48.04; Flight Crew Total 12000; Flight Crew Type 482.4
Distraction
Conflict NMAC
Flight Crew Took Evasive Action
Airspace Structure; Human Factors; Procedure
Near miss between piper PA-28 tow plane and glider approximately 2 miles west of gliderport. Both aircraft originated at same gliderport. At approximately 1800 AGL; clear skies visibility 10+ sun very high and behind/above the glider.  My Pawnee was climbing at the usual wide open throttle about 500 fpm at 80 mph with path crossing angle about 150 degrees nose to nose between my aircraft and the conflict sailplane. Sailplane had been towed to approximately 2500 AGL by another tow plane and appeared at my left 11 o'clock slightly high with zero angle rate.  Both glider instructor and I took evasive action. I believe the glider crew field of view where I approached the sailplane must have been obstructed by glider structure.  Very close to the merge; glider instructor broke right and up and I broke right and down.  Closest approach was in the order of three hundred feet radially; maybe less.  Target traffic acquired considerably later than I would have wished. [Sailplane] on tow w/instructor and student behind my Pawnee recognized the conflict a few seconds in advance just before the merge and released. My clearing scan must have broken down for a short time. There were about 4 total gliders operating with two Pawnee tows.  We tow pilots had been doing a good job of staying about 180 out of phase...worked hard at keeping situational awareness of the gliders in the air and pattern and getting the three gliders in the air without conflict. Both tow pilots cooperated with occasional radio calls; keeping one another in sight during a busy time. My tows totaled 13 that day with 11 2500 ft tows and two 4000 ft tows...the other tow pilot got 15 tows. Ceiling and vis and sun not a significant factor but there was a minor distraction of a large flock of soaring/migrating turkey vultures in the area that we shared the airspace with. The sailplane crew was likely doing a training maneuver which might have required their composite scan to be more inside the sailplane than usual.  All occurred in class e airspace
PA-28 tow pilot experiences a NMAC with a sailplane flying in the opposite direction. Both pilots take evasive action and the glider under tow releases.