B737-300 CREW ALLEGEDLY DEPARTED WITH FROST ON THE WINGS.

Narrative

ACFT NOT DEICED PRIOR TO DEP. I WAS A COCKPIT JUMP SEATER SEATED IN THE CABIN OF THE ACFT. THE ACFT WAS PUSHED BACK AND BEGAN TO TAXI WITHOUT BEING DEICED; I LOOKED OUT AND OBSERVED THAT THERE WAS FROST ADHERING TO THE TOP SIDE OF R WING FROM THE INBOARD PORTION OF THE AILERON OUT TO THE TIP. I PROCEEDED FORWARD AND ESTABLISHED COMS WITH THE FLT DECK AND ADVISED THEM OF THE FROST ON THE WING AND RETURNED TO MY SEAT. THE FO CAME BACK AND LOOKED AT THE WINGS AND RETURNED TO THE COCKPIT AND MADE AN ANNOUNCEMENT THAT SOMEONE HAD CONCERNS ABOUT FROST ON THE WINGS AND THAT IT WAS JUST CONDENSATION FROM REFUELING THE ACFT. THE ACFT THEN DEPARTED WITHOUT INCIDENT. THE FROST DID NOT SUBLIMATE UNTIL APPROX 10000 FT (ESTIMATED). THERE WAS A CPR PLT SEATED NEXT TO ME WHO ALSO SAW THE FROST AND EXPRESSED CONCERN. I ADVISED THE CREW UPON ARR THAT I WOULD FILE A RPT AND SUGGESTED THAT THEY DO THE SAME. SUPPLEMENTAL INFO FROM ACN 565046: JUST PRIOR TO TAKING THE RWY FOR DEP; THE FLT ATTENDANT CALL RANG. THE FO ANSWERED AND WAS TOLD A PAX SITTING NEXT TO A JUMP SEAT RIDER (COMPANY PLT) WAS CONCERNED ABOUT FROST ON THE WINGS. THE FO HAD PREVIOUSLY; UPON COMPLETION OF HIS PREFLT; MADE A POINT OF TELLING ME THE ACFT WAS GOOD AND DID NOT NEED DEICE. AFTER THE CALL; I SENT THE FO BACK TO CHK THE WINGS BY LOOKING OUT THE CABIN WINDOW. I AM VERY RELUCTANT TO LEAVE THE COCKPIT POST SEP/TUE. THE FO RETURNED AND SAID THE WINGS LOOKED GOOD TO HIM. I MADE THE DECISION TO CONTINUE OUR TKOF. THE DEP WAS NORMAL AND WE CONTINUED OUR TRIP. AT THE TIME OF THE CALL; I THOUGHT IT WAS THE FLT ATTENDANT CALLING TO RPT WHAT THE PAX HAD SAID TO THE JUMP SEATER/CABIN RIDER. LATER; I LEARNED IT WAS THE JUMP SEAT RIDER TALKING WITH THE FO. HAD I REALIZED THIS; I WOULD HAVE TALKED WITH THE JUMP SEAT CABIN RIDER AND GIVEN THE INFO MORE CREDITABILITY. LATER; TALKING WITH THE JUMP SEAT/CABIN RIDER; IT WAS HIS OPINION THAT THERE WAS SOME FROST ON THE OUTER PORTION OF THE WING. HAD I TALKED DIRECTLY WITH THE JUMP SEAT/CABIN RIDER BEFORE TKOF; I WOULD HAVE ASKED HIS OPINION AND IF THERE WAS FROST HE COULD SEE; RETURNED TO THE RAMP FOR DEICING.