Narrative:

I was working anc local control, anc ground control, and lake hood tower combined at anc local control. Air carrier X was departing anc runway 32 IFR to taipei on the anc 2 departure SID. Inbound from the north was a cessna (small aircraft Y) transitioning to campbell lake, which is located approximately 3 mi southeast of anc. Typically an aircraft such as this would be assigned the post office arrival, a VFR arrival procedure that keeps inbound VFR aircraft east of the departure course for aircraft departing runway 32. The small aircraft Y was initially radar idented by anc TRACON and I cannot verify whether this aircraft was issued the post office arrival or not. My initial contact with small aircraft Y was only one and one half mi north of the airport, which is unusually late, and I advised small aircraft Y about the heavy DC10 departing runway 32 nwbound. Small aircraft Y advised that they had the traffic in sight. Of note was the fact that small aircraft Y was flying sbound unusually close to runway 32, approximately only a half mi east of the runway. After air carrier X departed I advised them of the traffic, 'air carrier X, traffic ahead and right, sbound, a cessna, slightly higher.' as this traffic call was being made the d-brite indicated that small aircraft Y was at 900 ft, and air carrier X was at 600 ft, and the aircraft were separated by less than 1 mi laterally. Both aircraft were in sight by me and their position visually did not alarm me. After the aircraft passed, air carrier X advised that they had executed a TCASII resolution after receiving a TCASII warning, and that their TCASII had reported virtually 0 lateral separation and 300 ft of vertical separation. The crew advised that their RA indicated that they should climb on course. The air crew of air carrier X was very polite, but they asked me several questions about this event, and they advised that they would be filing a report. The pilot of small aircraft Y seemed unconcerned about the incident. I should add that due to the close proximity of several airports and landing areas near anchorage, the aircraft that typically fly here are used to flying near other aircraft. Air carrier X are unusual in anchorage, and apparently the scenario I have described is extremely unusual for them.

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Original NASA ASRS Text

Title: ATCT LCL CTLR WORKING COMBINED POS IN THE TWR GAVE AN ACR DC10 TFC INFO ON A CESSNA TRAVERSING THE TWR'S AIRSPACE VFR INTO A CLOSE BY LAKE ARPT. THE CESSNA WAS ALSO GIVEN TFC ON THE DEPARTING DC10 AND SAID HE WAS IN SIGHT. ACFT PASSED IN CLOSE PROX AND THE DC10 RECEIVED AND RESPONDED TO A TCASII RA. THE DC10 SAID HE WOULD BE FILING A RPT ON THIS INCIDENT. NEITHER THE TWR CTLR NOR THE CESSNA PLT THOUGHT IT WAS THAT CLOSE.

Narrative: I WAS WORKING ANC LCL CTL, ANC GND CTL, AND LAKE HOOD TWR COMBINED AT ANC LCL CTL. ACR X WAS DEPARTING ANC RWY 32 IFR TO TAIPEI ON THE ANC 2 DEP SID. INBOUND FROM THE N WAS A CESSNA (SMA Y) TRANSITIONING TO CAMPBELL LAKE, WHICH IS LOCATED APPROX 3 MI SE OF ANC. TYPICALLY AN ACFT SUCH AS THIS WOULD BE ASSIGNED THE POST OFFICE ARR, A VFR ARR PROC THAT KEEPS INBOUND VFR ACFT E OF THE DEP COURSE FOR ACFT DEPARTING RWY 32. THE SMA Y WAS INITIALLY RADAR IDENTED BY ANC TRACON AND I CANNOT VERIFY WHETHER THIS ACFT WAS ISSUED THE POST OFFICE ARR OR NOT. MY INITIAL CONTACT WITH SMA Y WAS ONLY ONE AND ONE HALF MI N OF THE ARPT, WHICH IS UNUSUALLY LATE, AND I ADVISED SMA Y ABOUT THE HVY DC10 DEPARTING RWY 32 NWBOUND. SMA Y ADVISED THAT THEY HAD THE TFC IN SIGHT. OF NOTE WAS THE FACT THAT SMA Y WAS FLYING SBOUND UNUSUALLY CLOSE TO RWY 32, APPROX ONLY A HALF MI E OF THE RWY. AFTER ACR X DEPARTED I ADVISED THEM OF THE TFC, 'ACR X, TFC AHEAD AND R, SBOUND, A CESSNA, SLIGHTLY HIGHER.' AS THIS TFC CALL WAS BEING MADE THE D-BRITE INDICATED THAT SMA Y WAS AT 900 FT, AND ACR X WAS AT 600 FT, AND THE ACFT WERE SEPARATED BY LESS THAN 1 MI LATERALLY. BOTH ACFT WERE IN SIGHT BY ME AND THEIR POS VISUALLY DID NOT ALARM ME. AFTER THE ACFT PASSED, ACR X ADVISED THAT THEY HAD EXECUTED A TCASII RESOLUTION AFTER RECEIVING A TCASII WARNING, AND THAT THEIR TCASII HAD RPTED VIRTUALLY 0 LATERAL SEPARATION AND 300 FT OF VERT SEPARATION. THE CREW ADVISED THAT THEIR RA INDICATED THAT THEY SHOULD CLB ON COURSE. THE AIR CREW OF ACR X WAS VERY POLITE, BUT THEY ASKED ME SEVERAL QUESTIONS ABOUT THIS EVENT, AND THEY ADVISED THAT THEY WOULD BE FILING A RPT. THE PLT OF SMA Y SEEMED UNCONCERNED ABOUT THE INCIDENT. I SHOULD ADD THAT DUE TO THE CLOSE PROX OF SEVERAL ARPTS AND LNDG AREAS NEAR ANCHORAGE, THE ACFT THAT TYPICALLY FLY HERE ARE USED TO FLYING NEAR OTHER ACFT. ACR X ARE UNUSUAL IN ANCHORAGE, AND APPARENTLY THE SCENARIO I HAVE DESCRIBED IS EXTREMELY UNUSUAL FOR THEM.

Data retrieved from NASA's ASRS site as of July 2007 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.