Air carrier captain reports conflict with sailplanes 15 miles east of grr at 5;000 ft. Some of the s...

Narrative:

Enroute to grr we were notified by cle center and grr approach that there was glider activity ahead. We were about about 15 miles east of grr at 5;000 ft below a 5;500 ft overcast when we spotted the first glider in a turn at our altitude approximately 3 miles ahead. We notified approach control of the traffic and it was quickly apparent that he did not hold this particular glider. The glider was white and could not be seen against the overcast unless it was in a turn. Approaching about 1 mile I turned 30 degrees left of course to remain clear of the traffic. Leveling the wings out of the turn we passed over a second glider and under a third clearing each by about 500 ft and 1/4 mile. Several additional gliders were visible on TCAS; but the 3 we avoided were not. Clear of the traffic I turned back on course and continued the vectors into grr. We received advance warning from ATC that we were approaching glider activity and were assisted in avoiding the gliders that were using transponders but we were not aware that some gliders did not have transponders. The vectors we received did not clear us of the entire area where the gliders were active and allowed us to come way too close before visual contact.

Original NASA ASRS Text

Title: Air Carrier Captain reports conflict with sailplanes 15 miles east of GRR at 5;000 FT. Some of the sailplanes were pointed out by ATC and detected on TCAS; but others were apparently not transponder equipped.

Narrative: Enroute to GRR we were notified by CLE Center and GRR Approach that there was glider activity ahead. We were about about 15 miles east of GRR at 5;000 FT below a 5;500 FT overcast when we spotted the first glider in a turn at our altitude approximately 3 miles ahead. We notified Approach Control of the traffic and it was quickly apparent that he did not hold this particular glider. The glider was white and could not be seen against the overcast unless it was in a turn. Approaching about 1 mile I turned 30 degrees left of course to remain clear of the traffic. Leveling the wings out of the turn we passed over a second glider and under a third clearing each by about 500 FT and 1/4 mile. Several additional gliders were visible on TCAS; but the 3 we avoided were not. Clear of the traffic I turned back on course and continued the vectors into GRR. We received advance warning from ATC that we were approaching glider activity and were assisted in avoiding the gliders that were using transponders but we were not aware that some gliders did not have transponders. The vectors we received did not clear us of the entire area where the gliders were active and allowed us to come way too close before visual contact.

Data retrieved from NASA's ASRS site as of July 2013 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	1013332
Time
Date	201205
Local Time Of Day	1201-1800
Place
Locale Reference	GRR.Airport
State Reference	MI
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Sail Plane
Operating Under FAR Part	Part 91
Flight Plan	None
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Track / Heading All Types

Air carrier captain reports conflict with sailplanes 15 miles east of grr at 5;000 ft. Some of the sailplanes were pointed out by ATC and detected on TCAS; but others were apparently not transponder equipped.