Narrative:

We were holding short of anc runway 32 at intersection K facing east. Tower cleared the aircraft Y on runway 32 for takeoff and then cleared us into position and hold. As we were lining up with the runway aircraft Y was passing what I estimate to be 400 ft AGL. At that time aircraft Z; a C130 appeared to pass directly underneath the aircraft Y with very little vertical clearance. Aircraft Y asked anc tower if they always cleared people for takeoff with other aircraft passing through final. Anc tower replied that they didn't know the C130 was going to pass through the departure path. The aircraft Y pilot did not mention TCAS so I don't know the status of his RA/TA. I would guess the solution would be to educate the aircraft Z pilots that they need to remain clear of the approach and departure paths of this fairly busy airport and to insist that the tower keep positive control over traffic in the pattern. From our vantage point it looked alarmingly close; and the C130 seemed to appear from 'nowhere' so I don't know where he had been operating before he flew through the departure track.

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Original NASA ASRS Text

Title: A COAST GUARD C130 PASSED AN EST. 400 FT DIRECTLY BENEATH AN ACR ACFT DEPARTING ANC. ATC DID NOT KNOW WHAT THE COAST GUARD WAS DOING.

Narrative: WE WERE HOLDING SHORT OF ANC RWY 32 AT INTXN K FACING E. TWR CLRED THE ACFT Y ON RWY 32 FOR TKOF AND THEN CLRED US INTO POS AND HOLD. AS WE WERE LINING UP WITH THE RWY ACFT Y WAS PASSING WHAT I ESTIMATE TO BE 400 FT AGL. AT THAT TIME ACFT Z; A C130 APPEARED TO PASS DIRECTLY UNDERNEATH THE ACFT Y WITH VERY LITTLE VERT CLRNC. ACFT Y ASKED ANC TWR IF THEY ALWAYS CLRED PEOPLE FOR TKOF WITH OTHER ACFT PASSING THROUGH FINAL. ANC TWR REPLIED THAT THEY DIDN'T KNOW THE C130 WAS GOING TO PASS THROUGH THE DEP PATH. THE ACFT Y PLT DID NOT MENTION TCAS SO I DON'T KNOW THE STATUS OF HIS RA/TA. I WOULD GUESS THE SOLUTION WOULD BE TO EDUCATE THE ACFT Z PLTS THAT THEY NEED TO REMAIN CLR OF THE APCH AND DEP PATHS OF THIS FAIRLY BUSY ARPT AND TO INSIST THAT THE TWR KEEP POSITIVE CTL OVER TFC IN THE PATTERN. FROM OUR VANTAGE POINT IT LOOKED ALARMINGLY CLOSE; AND THE C130 SEEMED TO APPEAR FROM 'NOWHERE' SO I DON'T KNOW WHERE HE HAD BEEN OPERATING BEFORE HE FLEW THROUGH THE DEP TRACK.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.