Narrative:

I was first officer on flight. We were cleared for the ILS 12 to dulles and told to switch tower 128.42. Tower told us the frequency for runway 12 was 120.1. I tried to call tower twice at the marker (arcoa), once at about 3 mi and several times short final. The captain tried as well, thinking maybe my microphone had failed. I also tried contact on 128.42 on our other radio. We could hear tower directing other traffic. It sounded like someone missed a high speed that resulted in the disruption of the planned flow of arrival/departure traffic. We could not hear some of the other aircraft tower was talking to, perhaps they were on the other frequency. We executed a missed approach at approximately 100 ft due to no landing clearance. During climb out at approximately 500 ft AGL, the so pointed out traffic. A B737 was passing left to right, our altitude and climbing. Separation was approximately 900 ft or less and would have been much closer had we not immediately turned left and descended. After we started maneuvering we did get a TA on the TCASII and a GPWS 'sink rate.' once clear of the traffic, tower called us and directed a turn to 040 degrees. We asked for an altitude and then were vectored for an approach to runway 19R. We spoke to the tower supervisor and he told us that the controller thought he had cleared us to land. I do not know why he didn't respond to any of our calls. The dual frequency operations seemed to add to the confusion on the tower frequency. We're not sure if the B737 jet was off a missed or departing. In hindsight, if I would have called the missed to tower immediately and he heard it, unlike all the other calls, perhaps he could have directed us or B737 away from each other.

Google
 

Original NASA ASRS Text

Title: WDB ACFT ON APCH ASSIGNED TWR FREQ ON WHICH THERE WAS NO ANSWER. FLC COULD HEAR OTHER XMISSIONS, BUT TWR DIDN'T ANSWER THEIR LNDG REQUEST. RPTR HAD TO GAR RESULTING IN A CONFLICT WITH ANOTHER ACFT. TWR CTLR THOUGHT HE HAD CLRED RPTR ACFT TO LAND.

Narrative: I WAS FO ON FLT. WE WERE CLRED FOR THE ILS 12 TO DULLES AND TOLD TO SWITCH TWR 128.42. TWR TOLD US THE FREQ FOR RWY 12 WAS 120.1. I TRIED TO CALL TWR TWICE AT THE MARKER (ARCOA), ONCE AT ABOUT 3 MI AND SEVERAL TIMES SHORT FINAL. THE CAPT TRIED AS WELL, THINKING MAYBE MY MIKE HAD FAILED. I ALSO TRIED CONTACT ON 128.42 ON OUR OTHER RADIO. WE COULD HEAR TWR DIRECTING OTHER TFC. IT SOUNDED LIKE SOMEONE MISSED A HIGH SPD THAT RESULTED IN THE DISRUPTION OF THE PLANNED FLOW OF ARR/DEP TFC. WE COULD NOT HEAR SOME OF THE OTHER ACFT TWR WAS TALKING TO, PERHAPS THEY WERE ON THE OTHER FREQ. WE EXECUTED A MISSED APCH AT APPROX 100 FT DUE TO NO LNDG CLRNC. DURING CLB OUT AT APPROX 500 FT AGL, THE SO POINTED OUT TFC. A B737 WAS PASSING L TO R, OUR ALT AND CLBING. SEPARATION WAS APPROX 900 FT OR LESS AND WOULD HAVE BEEN MUCH CLOSER HAD WE NOT IMMEDIATELY TURNED L AND DSNDED. AFTER WE STARTED MANEUVERING WE DID GET A TA ON THE TCASII AND A GPWS 'SINK RATE.' ONCE CLR OF THE TFC, TWR CALLED US AND DIRECTED A TURN TO 040 DEGS. WE ASKED FOR AN ALT AND THEN WERE VECTORED FOR AN APCH TO RWY 19R. WE SPOKE TO THE TWR SUPVR AND HE TOLD US THAT THE CTLR THOUGHT HE HAD CLRED US TO LAND. I DO NOT KNOW WHY HE DIDN'T RESPOND TO ANY OF OUR CALLS. THE DUAL FREQ OPS SEEMED TO ADD TO THE CONFUSION ON THE TWR FREQ. WE'RE NOT SURE IF THE B737 JET WAS OFF A MISSED OR DEPARTING. IN HINDSIGHT, IF I WOULD HAVE CALLED THE MISSED TO TWR IMMEDIATELY AND HE HEARD IT, UNLIKE ALL THE OTHER CALLS, PERHAPS HE COULD HAVE DIRECTED US OR B737 AWAY FROM EACH OTHER.

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.