Narrative:

We were executing an ILS in IMC. As my first officer announced 'approaching minimums, runway in sight,' I began my transition from flight director reference to visual reference for a hand flown landing. My airspeed was probably around 130-135 KIAS. As I was transitioning I suddenly saw a dark colored military helicopter on my approach path. He blended in visually with the dismal WX conditions. I did not notice any aircraft lighting. As I saw him, so did the dca tower controller. The controller issued an immediate and forceful ATC instruction to the helicopter. The helicopter executed an abrupt evasive maneuver and disappeared into the fog. I landed safely. This entire event lasted about 3-4 seconds. My aircraft (boeing 757) confign was gear down, full 30 degree flaps, on speed, on course, on glide path. Evasive maneuvering capability is limited under these circumstances. My altitude was about 300-400 ft above the potomac river. Airport terminals and control tower were to my left, prohibited area P-56 was to my right, and the helicopter in question was in the WX in front of me somewhere. I didn't feel I could execute a missed approach with that aircraft in the fog in front of me. We were still on landing profile and I decided landing was the safest course available. We made a normal exit from the runway to the left with much landing room left on runway 36. Taxied to the gate and parked. Made an immediate phone call to the tower supervisor and reported the incident. Then called my airline flight management supervisors and reported the incident and made a written report to the airline safety department upon arrival at my base that night. I am glad the visibility was good enough for the controller to see the helicopter in time to take action. If the visibility had been any less he wouldn't have. Callback conversation with reporter revealed the following information: reporter states that during his speaking with the tower facility at dca, a controller in training was handling the military traffic at the north end of the airport under the jurisdiction of another, more experienced, controller. The second controller is the one that took over the microphone and ordered the helicopter to leave the approach environment of the landing traffic. The reporter states that his training would normally cause him to execute a missed approach but that the possibility of another encounter with the same aircraft seemed like a good possibility and so decided that landing was the safest path to follow. He said that the phone conversation revealed that extensive training for a military exercise or operation was in progress and was being staged from the north part of the dca complex. The reporter doesn't know whether the helicopter pilot misunderstood his instructions or whether the controller issued such instructions in the first place.

Related reports:

Google
 

Original NASA ASRS Text

Title: B757 SIGHTS MIL HELI WHILE ENTERING LNDG TRANSITION MANEUVER AT DCA.

Narrative: WE WERE EXECUTING AN ILS IN IMC. AS MY FO ANNOUNCED 'APCHING MINIMUMS, RWY IN SIGHT,' I BEGAN MY TRANSITION FROM FLT DIRECTOR REF TO VISUAL REF FOR A HAND FLOWN LNDG. MY AIRSPD WAS PROBABLY AROUND 130-135 KIAS. AS I WAS TRANSITIONING I SUDDENLY SAW A DARK COLORED MIL HELI ON MY APCH PATH. HE BLENDED IN VISUALLY WITH THE DISMAL WX CONDITIONS. I DID NOT NOTICE ANY ACFT LIGHTING. AS I SAW HIM, SO DID THE DCA TWR CTLR. THE CTLR ISSUED AN IMMEDIATE AND FORCEFUL ATC INSTRUCTION TO THE HELI. THE HELI EXECUTED AN ABRUPT EVASIVE MANEUVER AND DISAPPEARED INTO THE FOG. I LANDED SAFELY. THIS ENTIRE EVENT LASTED ABOUT 3-4 SECONDS. MY ACFT (BOEING 757) CONFIGN WAS GEAR DOWN, FULL 30 DEG FLAPS, ON SPD, ON COURSE, ON GLIDE PATH. EVASIVE MANEUVERING CAPABILITY IS LIMITED UNDER THESE CIRCUMSTANCES. MY ALT WAS ABOUT 300-400 FT ABOVE THE POTOMAC RIVER. ARPT TERMINALS AND CTL TWR WERE TO MY L, PROHIBITED AREA P-56 WAS TO MY R, AND THE HELI IN QUESTION WAS IN THE WX IN FRONT OF ME SOMEWHERE. I DIDN'T FEEL I COULD EXECUTE A MISSED APCH WITH THAT ACFT IN THE FOG IN FRONT OF ME. WE WERE STILL ON LNDG PROFILE AND I DECIDED LNDG WAS THE SAFEST COURSE AVAILABLE. WE MADE A NORMAL EXIT FROM THE RWY TO THE L WITH MUCH LNDG ROOM LEFT ON RWY 36. TAXIED TO THE GATE AND PARKED. MADE AN IMMEDIATE PHONE CALL TO THE TWR SUPVR AND RPTED THE INCIDENT. THEN CALLED MY AIRLINE FLT MGMNT SUPVRS AND RPTED THE INCIDENT AND MADE A WRITTEN RPT TO THE AIRLINE SAFETY DEPT UPON ARR AT MY BASE THAT NIGHT. I AM GLAD THE VISIBILITY WAS GOOD ENOUGH FOR THE CTLR TO SEE THE HELI IN TIME TO TAKE ACTION. IF THE VISIBILITY HAD BEEN ANY LESS HE WOULDN'T HAVE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT DURING HIS SPEAKING WITH THE TWR FACILITY AT DCA, A CTLR IN TRAINING WAS HANDLING THE MIL TFC AT THE N END OF THE ARPT UNDER THE JURISDICTION OF ANOTHER, MORE EXPERIENCED, CTLR. THE SECOND CTLR IS THE ONE THAT TOOK OVER THE MIKE AND ORDERED THE HELI TO LEAVE THE APCH ENVIRONMENT OF THE LNDG TFC. THE RPTR STATES THAT HIS TRAINING WOULD NORMALLY CAUSE HIM TO EXECUTE A MISSED APCH BUT THAT THE POSSIBILITY OF ANOTHER ENCOUNTER WITH THE SAME ACFT SEEMED LIKE A GOOD POSSIBILITY AND SO DECIDED THAT LNDG WAS THE SAFEST PATH TO FOLLOW. HE SAID THAT THE PHONE CONVERSATION REVEALED THAT EXTENSIVE TRAINING FOR A MIL EXERCISE OR OP WAS IN PROGRESS AND WAS BEING STAGED FROM THE N PART OF THE DCA COMPLEX. THE RPTR DOESN'T KNOW WHETHER THE HELI PLT MISUNDERSTOOD HIS INSTRUCTIONS OR WHETHER THE CTLR ISSUED SUCH INSTRUCTIONS IN THE FIRST PLACE.

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.