A GLIDER PLT RPTS AN NMAC WITH A COMMUTER JET NEAR FDK AT 4500 FT.

Narrative

I WAS CLBING IN A THERMAL WITH ANOTHER GLIDER APPROX 3.5 NM N OF FDK ARPT. AS WE PASSED THROUGH 4500 FT MSL (APPROX 4200 FT AGL) WE WERE STARTLED BY THE SUDDEN APPEARANCE OF A RAPIDLY MOVING BLUE AND WHITE REGIONAL COMMUTER PASSING IN THE VICINITY OF 1000 FT OF OUR POS. THE JET'S CREW HAD APPARENTLY SEEN US FIRST BECAUSE IT APPEARED TO BE REACTING WITH A R TURNING DSCNT TO A SSE BEARING; AWAY FROM OUR POS. WX CONDITIONS AT THE TIME WERE VMC. AT THE TIME; APPROX XA05; THE SUN WAS IN THE WESTERN PART OF THE SKY; THERE WERE NO CLOUDS AND VISIBILITY WAS GREATER THAN 10 NM. THE WX WAS SO GOOD IN FACT THAT THE 'SEVERE CLR' CONDITIONS MAY HAVE CONTRIBUTED TO THIS EVENT BY PROVIDING NO BACKDROP TO PICK UP MOVEMENT. THE GLIDERS BEING DOWN SUN WITH RESPECT TO THE JET'S ORIGINAL COURSE FROM THE W; AND THE LIKELY FLASHING OF SUNLIGHT OFF THE WINGS OF THE 2 BANKED CIRCLING GLIDERS MAY HAVE AIDED IN THE JET' CREW SPOTTING THE GLIDERS. THAT AIRSPACE IS QUITE BUSY. FDK IS ADVERTISED AS MARYLAND'S SECOND BUSIEST ARPT. A SIGNIFICANT PERCENTAGE OF THE FLT ACTIVITY OF FDK IS ASSOCIATED WITH GLIDER OPS. I MADE A RADIO CALL TO POTOMAC ABOUT 2 HRS EARLIER ALERTING THEM OF GLIDER ACTIVITY UP TO 6000 FT NEAR FDK. THE FOLLOWING SUGGESTIONS ARE OFFERED AS SAFETY ENHANCING ACTIONS: 1) THE FDK GLIDER OP AND POTOMAC APCH APPEAR TO HAVE GOOD COORD. NOTIFYING POTOMAC OF GLIDER ACTIVITY UPON ITS INITIATION AND POTOMAC PASSING THAT INFO ROUTINELY TO INBOUND ACFT AT CHK-IN OR VIA ATIS IS MOST HELPFUL. 2) CONSIDERATION SHOULD BE GIVEN TO PLACING A NOTICE ON THE IFR PUBS OF HVY VFR OR 'GLIDER ACTIVITY' IN THIS AREA. IT IS CLRLY MARKED ON VFR DOCUMENTS BUT NOT ON THE IFR PLATES BEING USED BY INBOUND TFC TRANSITING THE AIRSPACE. THE VIKES ARR INTO RENO; NV; IS A FINE EXAMPLE OF THIS TYPE OF WARNING TO IFR INBOUND TFC. 3) ADDITIONALLY; APCH PROCS SHOULD BE FLOWN TO KEEP THE TRANSITING IAD BOUND IFR ACFT AT HIGHER ALTS UNTIL ABSOLUTELY NECESSARY TO DSND. THEIR HIGHER GND SPD AND COCKPIT WORKLOADS MAKE IT RISKY TO OPERATE AT LOWER ALTS WHERE THE VAST MAJORITY OF VFR TFC IS CONGREGATED. SUCH AN APCH WOULD BE CONSISTENT WITH THE LCL FLOW TFC MGMNT PROGRAM.