B757 ON SHORT FINAL FOR LGA INITIATES GAR BECAUSE OF MINIMAL SPACING WITH PRECEDING DEP ACFT.

Narrative

ON VERY SHORT FINAL; LDA ALPHA APCH TO RWY 22 AT LGA (RWY 13/31 CLOSED; DAY VFR; CLR 10 MI VISIBILITY; SOME HAZE); TWR TAXIED AN ACFT (ACR Y) INTO POS AND HOLD ON RWY 22 AND FORGOT HE WAS THERE. AT 300 FT ON FINAL; TWR CLRED US TO LAND ON RWY 22. I ADVISED HIM THAT HE STILL HAD AN ACFT STILL SITTING IN POS. TWR THEN TOLD THE ACR Y ACFT TO TAKE OFF. AT 150 FT HE FINALLY TOLD US TO GO AROUND; WHICH WE HAD ALREADY INITIATED ON OUR OWN. MY COPLT DID A TEXTBOOK GAR AS WE TURNED NW AS INSTRUCTED AND LEVELED AT 3000 FT. ALL CHKLISTS WERE ACCOMPLISHED AND A PA MADE TO THE PAX. IF IT HADN'T BEEN A CLR DAY AND WE WEREN'T ABLE TO SEE THE ACFT TAXI INTO POS; WE WOULD HAVE NEVER NOTICED HIM BECAUSE THE COLORS OF THE ACFT BLENDED IN PERFECTLY WITH THE RWY MARKINGS. I USED TO BE AN FPL CTLR AT LAS TRACON; AND PROC THERE WAS TO HOLD THE IFR STRIP OF THE ACFT IN YOUR HAND; AS LONG AS YOU HAD SOMEONE IN POS ON A RWY. IF THE WX HAD BEEN AT MINIMUMS WITH LOW VISIBILITY; THIS RPT WOULD HAVE BEEN WRITTEN BY OTHER WITNESSES.