LTT JET CROSSES RWY IN FACE OF SMT TAKING OFF FORCING IT TO ABORT TKOF.

Narrative

WE WERE #2 TO CROSS THE RWY BEHIND AN ARPT SECURITY VEHICLE. WHILE WAITING TO CROSS THE RWY THE CAPT AND I WERE TALKING ABOUT THE FLT AND ACFT. WE WERE HOLDING FOR ABOUT 1 MIN WHEN THE VEHICLE IN FRONT OF US CROSSED THE RWY. WE FOLLOWED SHORTLY AFTER. THE CAPT LOOKED TO HIS L TO SEE IF IT WAS CLR AND SAW AN ACFT DOWNFIELD ON THE NUMBERS WAITING FOR DEP. WE CROSSED THE ACTIVE TO LEARN THAT THIS SMT HAD TO ABORT ITS TKOF DUE TO TFC DOWNFIELD XING THE RWY. I LOOKED TO OUR L TO DISCOVER AN SMT DECELERATING ABOUT 1500 FT DOWN THE RWY. LATE AFTERNOON SUN WAS DIRECTLY IN THE LINE OF SIGHT BTWN OUR POS AND THE DEPARTING ACFT. ABOUT 1 HR OR SO LATER WE WERE TAXIING OUT FOR DEP AND GUESS WHAT -- IT HAPPENED AGAIN; ONLY THIS TIME WITH AN SMA. AS WE APCHED THE HOLD LINE TO CROSS THE RWY; WE STOPPED. THIS TIME THE TFC WAS COMING FROM MY SIDE. I LOOKED TO THE W TO SEE ONLY 2 THINGS; A BIG ORANGE SUN AND A HIGH WING ACFT TURNING SHORT FINAL. WE ELECTED TO HOLD. ONCE THE SMA LANDED I KEPT MY EYE ON IT AND OBSERVED WHAT APPEARED TO BE IT VACATING THE RWY TO THE S. SO WE SLOWLY PROCEEDED FORWARD AND I ANNOUNCED WE WERE XING THE RWY. JUST AS I RELEASED THE MIKE BUTTON THE SMA LIFTED OFF ON UPWIND. WE HAD TRAVELED AN AIRPLANE LENGTH FROM OUR ORIGINAL HOLDING POINT AND SMOOTHLY CAME TO A STOP.