C172 PLT HAS A 14 KT TAILWIND DURING LNDG.

Narrative

I WAS COMING INTO MY HOME BASE AT 3000 FT FROM THE E AND THE WIND AT THAT ALT WAS ABOUT A 35 KT HEADWIND. THERE WAS MILD TURB AND THE ATIS GAVE THE SURFACE WIND AS 220 DEGS AT 16 KTS. I CALLED THE TWR AND WAS CLRED TO A R BASE TO RWY 2L BEHIND A LEARJET LNDG ON RWY 2R. I DID A QUICK MENTAL ESTIMATE AND DECIDED THE XWIND COMPONENT WAS OK; BUT THE TAILWIND COMPONENT WOULD BE CONSIDERABLE. THE LEARJET AHEAD OF ME COMPLAINED TO THE TWR ABOUT THE WINDSHEAR AND TAILWIND LNDG AFTER HE WAS ON THE GND. RWY 2R IS 6000 FT AND HE HAD THRUST REVERSAL. I CONFIGURED FOR EXPECTED TURB ON FINAL AND WAS NOT DISAPPOINTED. THE APCH AND LNDG REQUIRED FULL CONCENTRATION. IT FELT LIKE A LOT MORE XWIND; PROBABLY BECAUSE OF THE TAILWIND. IN A LIGHTLY LOADED C172; I USED OVER 3000 FT OF A 3700 FT RWY. IN A HEAVIER; FASTER ACFT; I WOULD HAVE GONE AROUND AND REQUESTED THE LONGER RWY. LATER CALCULATION GAVE A 6 KT XWIND COMPONENT AND A 14 KT TAILWIND. THE TWR IS OFTEN RELUCTANT TO CHANGE RWYS TO MATCH THE PREVAILING WIND. I CAN UNDERSTAND THIS BECAUSE TFC IS VERY HVY AND THE CHANGE IS DISRUPTIVE. HOWEVER; SOMETIMES IT IS A BIT MUCH TO DEAL WITH; AND THIS TIME IT WAS PROBABLY BEYOND THE CAPABILITIES OF SOME. CTL TWRS DO NOT HAVE ANY PROVISION FOR RPTING XWIND AND DOWNWIND COMPONENT. I HAVE AN E6B ON BOARD; BUT THE COMPUTATION TAKES TIME AND DURING AN APCH THERE IS LITTLE TIME AND A BUSY ARPT IS NOT THE PLACE TO HAVE YOUR HEAD IN THE COCKPIT. IT WOULD HELP WITH CRITICAL DECISION MAKING TO HAVE THIS INFO FROM THE TWR IF REQUESTED. A REQUIRED WARNING FROM THE TWR WHEN THE TAILWIND COMPONENT EXCEEDS 5 OR 10 KTS ITS NOT A BAD IDEA. IT WOULD SERVE TO ALERT BOTH PLTS AND THE TWR CREW.