Narrative:

On approach into dca about 15 mi out and approaching vicinity of andrews AFB. Dca approach cleared us from 6000 ft to 2000 ft. My captain acknowledged descent and I started down at 1000 FPM. There was another company flight (Z) with a similar call sign that this controller had previously cleared to 2000 ft. When level at 2000 ft we were asked 'our call sign, what do you believe your last assigned altitude was?' my captain replied with assertion ' our call sign, we're at 2000 ft as assigned,' or similar words to that effect. The controller said, 'turn right to 320.' I saw an air force transport jet Y go under and right of us (on approach to andrews) about level 1000 ft below our flight path. Both of us heard 2000 ft as an assigned altitude for our aircraft X. I believe the controller wanted us at 3000 ft, not 2000 ft, but had 2000 ft on his mind, as he had cleared company flight, Z, to 2000 ft previously. In any case the readback acknowledgement, the last chance to correct a misunderstanding, was heard and accepted without comment by our controller. My captain asked if he should call in the ground and the controller said 'no problem.' I think there may be a problem or I wouldn't be sending this in.

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Original NASA ASRS Text

Title: LTSS BTWN COMMUTER AND MIL TRANSPORT AFTER UNCOORD PENETRATION OF ADW ATA AIRSPACE. OPERATIONAL ERROR.

Narrative: ON APCH INTO DCA ABOUT 15 MI OUT AND APCHING VICINITY OF ANDREWS AFB. DCA APCH CLRED US FROM 6000 FT TO 2000 FT. MY CAPT ACKNOWLEDGED DSCNT AND I STARTED DOWN AT 1000 FPM. THERE WAS ANOTHER COMPANY FLT (Z) WITH A SIMILAR CALL SIGN THAT THIS CTLR HAD PREVIOUSLY CLRED TO 2000 FT. WHEN LEVEL AT 2000 FT WE WERE ASKED 'OUR CALL SIGN, WHAT DO YOU BELIEVE YOUR LAST ASSIGNED ALT WAS?' MY CAPT REPLIED WITH ASSERTION ' OUR CALL SIGN, WE'RE AT 2000 FT AS ASSIGNED,' OR SIMILAR WORDS TO THAT EFFECT. THE CTLR SAID, 'TURN R TO 320.' I SAW AN AIR FORCE TRANSPORT JET Y GO UNDER AND R OF US (ON APCH TO ANDREWS) ABOUT LEVEL 1000 FT BELOW OUR FLT PATH. BOTH OF US HEARD 2000 FT AS AN ASSIGNED ALT FOR OUR ACFT X. I BELIEVE THE CTLR WANTED US AT 3000 FT, NOT 2000 FT, BUT HAD 2000 FT ON HIS MIND, AS HE HAD CLRED COMPANY FLT, Z, TO 2000 FT PREVIOUSLY. IN ANY CASE THE READBACK ACKNOWLEDGEMENT, THE LAST CHANCE TO CORRECT A MISUNDERSTANDING, WAS HEARD AND ACCEPTED WITHOUT COMMENT BY OUR CTLR. MY CAPT ASKED IF HE SHOULD CALL IN THE GND AND THE CTLR SAID 'NO PROBLEM.' I THINK THERE MAY BE A PROBLEM OR I WOULDN'T BE SENDING THIS IN.

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.