Narrative:

MTR Y inbound to adw. Air carrier X off iad, climbed in front of MTR Y. MTR Y may have overshot assigned altitude. Callback conversation with reporter acn 111107 revealed the following: the reporter was working combined positions at the time of the incident (approach and feeder). He has 3 yrs fpl time and 4 yrs military. There were 4 aircraft being worked during this period--2 of them in the process of being handed off to an adjacent facility which distracted him from the other aircraft under his control. The incident occurred above the arsa in other controled airspace. He said the air carrier had departed on an SID and that the MTR was on finks STAR arrival. The recording tape was malfunctioning at the time and did not record any of the xmissions between the MTR and his position. There was about 20 mins of tape missing. Further investigation revealed that there were other periods of missing recordings also. A new recorder head was installed to rectify the problem. The reporter did not issue an altitude, nor to the best of his knowledge, receive or hear an altitude from the MTR while the aircraft was on his frequency. It was his impression that the MTR was descending to 8000', not 7000. The facility has classified the incident as a pilot deviation. Supplemental information from acn 111495: air carrier X, widebody transport departure off of dulles, was radar idented and climbed to 7000'. Approximately 4 mins later the pilot of air carrier X asked if I had any traffic for him. I replied that there was traffic descending over the airport to 8000' landing adw. He then told me that an MTR passed right in front of him at his altitude. Just prior to this time, I observed traffic at 8000' sebnd, then the observed target went into CST and no mode C was available. Just after the pilot reported the traffic, I slewed to the target and displayed the full data block showing the MTR again at 8000'. The MTR had left his assigned altitude of 8000', passing within 4/100 of a mile and 100' vertical of the air carrier that I was working. The altitude had changed so quickly the computer was unable to update mode C. Supplemental information from acn 111093: checked in on my frequency level at 15000'. I issued dulles altimeterand told him to turn left heading 030 degrees vector for descent, to descend and maintain 12000'. The pilot asked me to repeat the altitude and advised that 030 degrees would not be favorable due to WX and asked if I was aware that his destination was adw. I said yes, and he advised that he was being vectored to follow traffic descending over aml en route to dca. The pilot never read back the heading or the altitude, but I noted through ARTS readout that he had complied with both. My next transmission, minutes later, was: 'MTR Y turn right direct aml direct adw, descend to cross aml at and maintain 8000.' MTR Y read the clearance back correctly. I then switched MTR Y prior to the tcp (aml) to dca approach. MTR Y was out of 10900' when he acknowledged the communications transfer. Supplemental information from acn 111299: approximately 4 mins after takeoff, being vectored by dulles departure control, level 7000', IFR layered scuddy clouds, an MTR passed level, left to right in front, approximately 200-500' away. No evasive action taken. Incident reported immediately to departure control who gave vague reply that there was traffic in the area at 8000'. Follow up conversations with departure control, center supervisors, company flight control, eventually yielded acknowledgement MTR was at 7000'. Departure control never acknowledged to us the MTR was there--that it was at 7000'--and yet it appears well established now the MTR was at 7000' and I believe early reports say ATC had C/a's going off. We pilots were hardly being well informed. Supplemental information from acn 111958: we were hearing 360 degrees at 7000' in and out of the clouds. At 1 point we broke out of the clouds and saw the MTR pass directly in front of us. We were never told of his whereabouts by the controller. After he passed we asked the controller of the traffic. His response was the only traffic was at 8000'. Supplemental information from acn 111082: descending into the washington area on finks 2 arrival, I leveled off at 7000' MSL, as I believed I was cleared. I had called to the approach controller (I think dca approach) that I was descending to 7000' in an attempt to verify the altitude, since I knew the area was congestedand the WX poor. Shortly after leveling off I was told I had traffic at '12 O'clock, less than a mile, unverified,' which caused me to take immediate evasive action--an afterburner climb to the next higher IFR altitude (8000'). I continued to my destination and landed uneventfully, after which I submitted a hatr (USAF form 651) to andrews AFB operations (attached copy). Additional comments: 1) conversation with dulles area manager post-flight indicated dulles approach believed I was cleared to 8000'. I remember only that I thought 7000' was the altitude and that I had confirmed it with approach by radio. This should be on dca approach tapes. 2) just prior to the traffic advisory that I responded to, approach asked me what my altitude was. I forgot this initially, but now it seems strange. My mode C IFF had been working fine. 3) ATC seemed much more interested, immediately after the incident, with collecting information about it than in assisting me to a safe landing. I was still trying to get a single-plted, fuel-limited, high performance aircraft on the ground in deteriorating WX, and I didn't get much help. Callback conversation with reporter acn 111082 revealed the following: reporter states investigation in progress by several agencies. Further states he had acknowledged initial clearance to maintain 8000', but became distracted with other duties & erroneously continued descent to 7000'. During this period he was switched by dulles approach to washington approach & when on new frequency, he reported he was descending to 7000' & that controller read back 7000'. He is also extremely puzzled by the fact when the traffic alert was issued. The term unverified was used even though the traffic was an IFR widebody transport less than 1 mi away. He states that he did not acquire the widebody transport visually but took immediate evasive action based on the traffic alert. Appears that many factions are engaged in the investigation, each representing their point of view & interests.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN MTR DESCENDED TO AN ALT OCCUPIED BY ANOTHER ACFT RESULTING IN EVASIVE ACTION BEING TAKEN BY THE MTR.

Narrative: MTR Y INBND TO ADW. ACR X OFF IAD, CLBED IN FRONT OF MTR Y. MTR Y MAY HAVE OVERSHOT ASSIGNED ALT. CALLBACK CONVERSATION WITH RPTR ACN 111107 REVEALED THE FOLLOWING: THE RPTR WAS WORKING COMBINED POSITIONS AT THE TIME OF THE INCIDENT (APCH AND FEEDER). HE HAS 3 YRS FPL TIME AND 4 YRS MIL. THERE WERE 4 ACFT BEING WORKED DURING THIS PERIOD--2 OF THEM IN THE PROCESS OF BEING HANDED OFF TO AN ADJACENT FAC WHICH DISTRACTED HIM FROM THE OTHER ACFT UNDER HIS CTL. THE INCIDENT OCCURRED ABOVE THE ARSA IN OTHER CTLED AIRSPACE. HE SAID THE ACR HAD DEPARTED ON AN SID AND THAT THE MTR WAS ON FINKS STAR ARR. THE RECORDING TAPE WAS MALFUNCTIONING AT THE TIME AND DID NOT RECORD ANY OF THE XMISSIONS BTWN THE MTR AND HIS POS. THERE WAS ABOUT 20 MINS OF TAPE MISSING. FURTHER INVESTIGATION REVEALED THAT THERE WERE OTHER PERIODS OF MISSING RECORDINGS ALSO. A NEW RECORDER HEAD WAS INSTALLED TO RECTIFY THE PROB. THE RPTR DID NOT ISSUE AN ALT, NOR TO THE BEST OF HIS KNOWLEDGE, RECEIVE OR HEAR AN ALT FROM THE MTR WHILE THE ACFT WAS ON HIS FREQ. IT WAS HIS IMPRESSION THAT THE MTR WAS DSNDING TO 8000', NOT 7000. THE FAC HAS CLASSIFIED THE INCIDENT AS A PLTDEV. SUPPLEMENTAL INFO FROM ACN 111495: ACR X, WDB DEP OFF OF DULLES, WAS RADAR IDENTED AND CLBED TO 7000'. APPROX 4 MINS LATER THE PLT OF ACR X ASKED IF I HAD ANY TFC FOR HIM. I REPLIED THAT THERE WAS TFC DSNDING OVER THE ARPT TO 8000' LNDG ADW. HE THEN TOLD ME THAT AN MTR PASSED RIGHT IN FRONT OF HIM AT HIS ALT. JUST PRIOR TO THIS TIME, I OBSERVED TFC AT 8000' SEBND, THEN THE OBSERVED TARGET WENT INTO CST AND NO MODE C WAS AVAILABLE. JUST AFTER THE PLT RPTED THE TFC, I SLEWED TO THE TARGET AND DISPLAYED THE FULL DATA BLOCK SHOWING THE MTR AGAIN AT 8000'. THE MTR HAD LEFT HIS ASSIGNED ALT OF 8000', PASSING WITHIN 4/100 OF A MILE AND 100' VERT OF THE ACR THAT I WAS WORKING. THE ALT HAD CHANGED SO QUICKLY THE COMPUTER WAS UNABLE TO UPDATE MODE C. SUPPLEMENTAL INFO FROM ACN 111093: CHKED IN ON MY FREQ LEVEL AT 15000'. I ISSUED DULLES ALTIMETERAND TOLD HIM TO TURN LEFT HDG 030 DEGS VECTOR FOR DSCNT, TO DSND AND MAINTAIN 12000'. THE PLT ASKED ME TO REPEAT THE ALT AND ADVISED THAT 030 DEGS WOULD NOT BE FAVORABLE DUE TO WX AND ASKED IF I WAS AWARE THAT HIS DEST WAS ADW. I SAID YES, AND HE ADVISED THAT HE WAS BEING VECTORED TO FOLLOW TFC DSNDING OVER AML ENRTE TO DCA. THE PLT NEVER READ BACK THE HDG OR THE ALT, BUT I NOTED THROUGH ARTS READOUT THAT HE HAD COMPLIED WITH BOTH. MY NEXT XMISSION, MINUTES LATER, WAS: 'MTR Y TURN RIGHT DIRECT AML DIRECT ADW, DSND TO CROSS AML AT AND MAINTAIN 8000.' MTR Y READ THE CLRNC BACK CORRECTLY. I THEN SWITCHED MTR Y PRIOR TO THE TCP (AML) TO DCA APCH. MTR Y WAS OUT OF 10900' WHEN HE ACKNOWLEDGED THE COMS TRANSFER. SUPPLEMENTAL INFO FROM ACN 111299: APPROX 4 MINS AFTER TKOF, BEING VECTORED BY DULLES DEP CTL, LEVEL 7000', IFR LAYERED SCUDDY CLOUDS, AN MTR PASSED LEVEL, LEFT TO RIGHT IN FRONT, APPROX 200-500' AWAY. NO EVASIVE ACTION TAKEN. INCIDENT RPTED IMMEDIATELY TO DEP CTL WHO GAVE VAGUE REPLY THAT THERE WAS TFC IN THE AREA AT 8000'. FOLLOW UP CONVERSATIONS WITH DEP CTL, CENTER SUPVRS, COMPANY FLT CTL, EVENTUALLY YIELDED ACKNOWLEDGEMENT MTR WAS AT 7000'. DEP CTL NEVER ACKNOWLEDGED TO US THE MTR WAS THERE--THAT IT WAS AT 7000'--AND YET IT APPEARS WELL ESTABLISHED NOW THE MTR WAS AT 7000' AND I BELIEVE EARLY RPTS SAY ATC HAD C/A'S GOING OFF. WE PLTS WERE HARDLY BEING WELL INFORMED. SUPPLEMENTAL INFO FROM ACN 111958: WE WERE HEARING 360 DEGS AT 7000' IN AND OUT OF THE CLOUDS. AT 1 POINT WE BROKE OUT OF THE CLOUDS AND SAW THE MTR PASS DIRECTLY IN FRONT OF US. WE WERE NEVER TOLD OF HIS WHEREABOUTS BY THE CTLR. AFTER HE PASSED WE ASKED THE CTLR OF THE TFC. HIS RESPONSE WAS THE ONLY TFC WAS AT 8000'. SUPPLEMENTAL INFO FROM ACN 111082: DSNDING INTO THE WASHINGTON AREA ON FINKS 2 ARR, I LEVELED OFF AT 7000' MSL, AS I BELIEVED I WAS CLRED. I HAD CALLED TO THE APCH CTLR (I THINK DCA APCH) THAT I WAS DSNDING TO 7000' IN AN ATTEMPT TO VERIFY THE ALT, SINCE I KNEW THE AREA WAS CONGESTEDAND THE WX POOR. SHORTLY AFTER LEVELING OFF I WAS TOLD I HAD TFC AT '12 O'CLOCK, LESS THAN A MILE, UNVERIFIED,' WHICH CAUSED ME TO TAKE IMMEDIATE EVASIVE ACTION--AN AFTERBURNER CLB TO THE NEXT HIGHER IFR ALT (8000'). I CONTINUED TO MY DEST AND LANDED UNEVENTFULLY, AFTER WHICH I SUBMITTED A HATR (USAF FORM 651) TO ANDREWS AFB OPS (ATTACHED COPY). ADDITIONAL COMMENTS: 1) CONVERSATION WITH DULLES AREA MGR POST-FLT INDICATED DULLES APCH BELIEVED I WAS CLRED TO 8000'. I REMEMBER ONLY THAT I THOUGHT 7000' WAS THE ALT AND THAT I HAD CONFIRMED IT WITH APCH BY RADIO. THIS SHOULD BE ON DCA APCH TAPES. 2) JUST PRIOR TO THE TFC ADVISORY THAT I RESPONDED TO, APCH ASKED ME WHAT MY ALT WAS. I FORGOT THIS INITIALLY, BUT NOW IT SEEMS STRANGE. MY MODE C IFF HAD BEEN WORKING FINE. 3) ATC SEEMED MUCH MORE INTERESTED, IMMEDIATELY AFTER THE INCIDENT, WITH COLLECTING INFO ABOUT IT THAN IN ASSISTING ME TO A SAFE LNDG. I WAS STILL TRYING TO GET A SINGLE-PLTED, FUEL-LIMITED, HIGH PERFORMANCE ACFT ON THE GND IN DETERIORATING WX, AND I DIDN'T GET MUCH HELP. CALLBACK CONVERSATION WITH RPTR ACN 111082 REVEALED THE FOLLOWING: RPTR STATES INVESTIGATION IN PROGRESS BY SEVERAL AGENCIES. FURTHER STATES HE HAD ACKNOWLEDGED INITIAL CLRNC TO MAINTAIN 8000', BUT BECAME DISTRACTED WITH OTHER DUTIES & ERRONEOUSLY CONTINUED DSCNT TO 7000'. DURING THIS PERIOD HE WAS SWITCHED BY DULLES APCH TO WASHINGTON APCH & WHEN ON NEW FREQ, HE RPTED HE WAS DSNDING TO 7000' & THAT CTLR READ BACK 7000'. HE IS ALSO EXTREMELY PUZZLED BY THE FACT WHEN THE TFC ALERT WAS ISSUED. THE TERM UNVERIFIED WAS USED EVEN THOUGH THE TFC WAS AN IFR WDB LESS THAN 1 MI AWAY. HE STATES THAT HE DID NOT ACQUIRE THE WDB VISUALLY BUT TOOK IMMEDIATE EVASIVE ACTION BASED ON THE TFC ALERT. APPEARS THAT MANY FACTIONS ARE ENGAGED IN THE INVESTIGATION, EACH REPRESENTING THEIR POINT OF VIEW & INTERESTS.

Data retrieved from NASA's ASRS site as of August 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.