FAA FLT CHK CREW ON A LOW APCH DOWN RWY 35 AT MHT CLIMB WHEN A STINSON L-5 STARTED TO TAXI ACROSS THE RWY.

Narrative

AS WE WERE MAKING A LOW APCH RECORDED RUN ON RWY 35 TO CERTIFY THE MHT ILS GS; THE CTL TWR CLRED US FOR THE LOW APCH. ABOUT 1/3 DOWN THE RWY; A STINSON TAILDRAGGER CROSSED THE RWY. I TOLD THE CREW TO WATCH THIS. JUST THEN; THE TWR SAID 'CLB.' I HAD INITIATED A CLB JUST AS HE SAID 'CLB.' I CLBED TO ABOUT 100 FT TO CONTINUE THE LOW APCH. OUR FLT WAS WORKING IN THE MHT PATTERN FOR THE LAST 2 1/2 HRS WORKING ON THE GS. IT APPEARS THAT A MISUNDERSTANDING BTWN LCL AND GND CTL MAY HAVE BEEN THE CAUSE OF THE EVENT. SUPPLEMENTAL INFO FROM ACN 593930: WHILE FLT CHKING MANCHESTER ILS RWY 35; I WAS IN A BE300. WE WERE FLYING 50 FT OVER THE RWY ABOUT 2000 FT FROM THE DEP END. THE PF NOTICED AN ACFT ON THE TXWY TO THE R MOVING TOWARD THE RWY. IT APPEARED TO BE A STINSON. THE ACFT TAXIED ACROSS THE RWY AND WE IMMEDIATELY CLBED TO 100 FT XING OVER THE ACFT. WE HEARD MANCHESTER TWR CALL 'GO AROUND' AT THE SAME TIME WE INITIATED THE CLB. WE HAD BEEN GIVEN A CLRNC FOR THE LOW APCH PRIOR TO OUR RUN. WE WERE IN THE TFC PATTERN FOR OVER 2 1/2 HRS PRIOR TO THIS EVENT. IT APPEARS A CONFLICT BTWN TWR AND GND MAY HAVE CAUSED THIS CLOSE CALL.