Narrative:

We were filed on the shnon one RNAV arrival into iad; and planning for runways 1L or 1R. We were given a clearance direct from mgw to esl; which eliminates the shaar waypoint; and also given the clearance to cross 25 miles west of esl at FL250; then slow to 290 KTS. FL250 is the same altitude as depicted for shaar. We were just past the top of descent point when given this clearance so started down as soon as we programmed and recognized where 25 miles west of esl put us. Sometime after starting the descent; we picked up the new ATIS which was advertising runways 19L/right and 12. My guess was that we would be cleared for the visual to runway 12 as is the past practice for eastbound flights into iad. The first officer was completing the approach descent checklist and dealing with a couple of cabin write ups so I selected and entered the ILS to runway 12 into the FMC; then turned away to take out the approach plate from my chart book and started to set up for the ILS to runway 12. Somewhere in this period of time; we received a frequency change and a new clearance to cross 5 miles west of druzz at 11;000 ft; then slow to 250 KTS. Druzz already has an 'expect clearance' restriction to cross at 250 KTS and 11;000 ft. It was about here that both the first officer and I realized that the map display was completely gone except for the runway and missed approach depictions; some 75 miles away -- the FMC was alerting us to the discontinuity. I knew we were still somewhere west of esl; but did not know how far. We had a couple of altitude and speed clearances that we were trying to comply with. The first officer and I both jumped into the FMC to try to sort this out. My thought (and training) dictated that I dial up esl on the VOR and establish our position. I went to the chart; and because we were on an RNAV arrival; esl becomes a waypoint; not a VOR; so no frequency is depicted. I tried reselecting the SHNON1 arrival; but the FMC did not allow me to due to fact that the ILS runway 12 was also selected; a point that we deduced sometime later. At one point; I had directed the first officer to ask for direct to druzz; which was refused by the controller due to spacing. It was about this time that we got ourselves sorted out. We finally got esl back onto the map and as druzz was the next fix (after canceling each other out at least once); and at least we had a course to go to. This took a little longer; because we were both 'in the box' I should have been flying the airplane and allowed the first officer to handle the programming; a thought that occurred to me after we landed and critiqued what had happened to us. We were both task saturated for a couple of minutes; the first officer with communications; checklists and changes; and me with clearance compliance; briefings and planning. We reestablished ourselves onto the arrival prior to esl by selecting the ILS runway 19R; which in turn; allowed the SHNON1 to be displayed and line selectable. We also complied with the speed and altitude clearances (somewhat of a miracle; I must say!) upon contact with potomac approach; we were told to expect a visual to runway 12. At this point; we had speculated that the source of our problem was my selection of the ILS runway 12 during the initial part of the descent. We now selected runway 12 after being told to expect it; but did not execute it; as we were still on the arrival routing and we did not care to have a repeat of preceding events. We made the southerly turn at razzz at exactly the same time we were given a potomac frequency change. We relayed to the new controller that we were still on the depicted routing. He gave us a turn back to 020 degrees (a 140 degree change in direction) and cleared us to intercept the localizer. We then executed the ILS runway 12 in the FMC and sure enough; all of the remaining SHNON1 disappeared. We then extended the final fix and flew the rest of the procedure in accordance with sops. Some confusion continued as we did not receive a hand off to tower. The first officer switched to tower at about 1500 ft AGL and we were clearedto land on runway 19R. The first officer queried the controller to establish that we were in fact cleared to land on runway 12; which was confirmed by the controller. After landing; the first officer established that we could 'roll to the end;' then let the controller know we would be switching to ground as we exited the runway; as we were not directed to do so. These errors lead me to believe that there was some confusion or lack of coordination both in the TRACON and the tower facilities as well. Questions: after review of the RNAV arrival (in the comfort of my own monday morning quarterback chair); I see that under the routing and landing description boxes; the procedure is specific to the north/south runways. If; as in our case; the runway is ultimately not the one that was planned for; what is to prevent the situation from developing as I have described above? If; for instance; we had received a new ATIS that alerted us to the possibility of landing on a runway not tied to the arrival much earlier in the flight; would we be expected to work out a new clearance with ATC so that we would be able to program an arrival; and a runway; with the sort of discontinuity we are expecting to see between the end of the STAR and the initial approach fix? How many of the new RNAV arrivals will disappear? If a different runway is selected from the FMC and executed; is this an anomaly in our fmcs and if so; is there a change coming? If not; is there adequate coordination between our dispatch and the TRACON? Finally; one of the main purposes of any RNAV procedure is to allow airplanes with fmcs to fly in such a manner that it is efficient; both in terms of pilot/controller workload and fuel/emissions. Why then; were we given clearances that mostly mirrored the operational constraints of the procedure; but required much extra programming and communications on both the part of the controller and pilots? The possibility for errors dramatically increases and in our case; we were left without any sa for a couple of minutes until we got our FMC generated map back. That is all we had; as one cannot back up an RNAV procedure with raw data. Lessons learned: how wonderful it is to have a competent and capable first officer!! Second; situation back; fly the airplane and let him do his competent things! He suggested filing these reports and also following up with the TRACON. My input to this was to tell him that the reports were an excellent idea.

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Original NASA ASRS Text

Title: A B757 FMC DROPPED THE IAD SHNON ONE RNAV ARR AFTER THE CREW PROGRAMMED A NON-RNAV RWY APCH.

Narrative: WE WERE FILED ON THE SHNON ONE RNAV ARRIVAL INTO IAD; AND PLANNING FOR RWYS 1L OR 1R. WE WERE GIVEN A CLEARANCE DIRECT FROM MGW TO ESL; WHICH ELIMINATES THE SHAAR WAYPOINT; AND ALSO GIVEN THE CLEARANCE TO CROSS 25 MILES WEST OF ESL AT FL250; THEN SLOW TO 290 KTS. FL250 IS THE SAME ALTITUDE AS DEPICTED FOR SHAAR. WE WERE JUST PAST THE TOP OF DESCENT POINT WHEN GIVEN THIS CLEARANCE SO STARTED DOWN AS SOON AS WE PROGRAMMED AND RECOGNIZED WHERE 25 MILES WEST OF ESL PUT US. SOMETIME AFTER STARTING THE DESCENT; WE PICKED UP THE NEW ATIS WHICH WAS ADVERTISING RWYS 19L/R AND 12. MY GUESS WAS THAT WE WOULD BE CLEARED FOR THE VISUAL TO RWY 12 AS IS THE PAST PRACTICE FOR EASTBOUND FLIGHTS INTO IAD. THE FO WAS COMPLETING THE APPROACH DESCENT CHECKLIST AND DEALING WITH A COUPLE OF CABIN WRITE UPS SO I SELECTED AND ENTERED THE ILS TO RWY 12 INTO THE FMC; THEN TURNED AWAY TO TAKE OUT THE APPROACH PLATE FROM MY CHART BOOK AND STARTED TO SET UP FOR THE ILS TO RWY 12. SOMEWHERE IN THIS PERIOD OF TIME; WE RECEIVED A FREQUENCY CHANGE AND A NEW CLEARANCE TO CROSS 5 MILES WEST OF DRUZZ AT 11;000 FT; THEN SLOW TO 250 KTS. DRUZZ ALREADY HAS AN 'EXPECT CLEARANCE' RESTRICTION TO CROSS AT 250 KTS AND 11;000 FT. IT WAS ABOUT HERE THAT BOTH THE FO AND I REALIZED THAT THE MAP DISPLAY WAS COMPLETELY GONE EXCEPT FOR THE RUNWAY AND MISSED APPROACH DEPICTIONS; SOME 75 MILES AWAY -- THE FMC WAS ALERTING US TO THE DISCONTINUITY. I KNEW WE WERE STILL SOMEWHERE WEST OF ESL; BUT DID NOT KNOW HOW FAR. WE HAD A COUPLE OF ALTITUDE AND SPEED CLEARANCES THAT WE WERE TRYING TO COMPLY WITH. THE FO AND I BOTH JUMPED INTO THE FMC TO TRY TO SORT THIS OUT. MY THOUGHT (AND TRAINING) DICTATED THAT I DIAL UP ESL ON THE VOR AND ESTABLISH OUR POSITION. I WENT TO THE CHART; AND BECAUSE WE WERE ON AN RNAV ARRIVAL; ESL BECOMES A WAYPOINT; NOT A VOR; SO NO FREQUENCY IS DEPICTED. I TRIED RESELECTING THE SHNON1 ARRIVAL; BUT THE FMC DID NOT ALLOW ME TO DUE TO FACT THAT THE ILS RWY 12 WAS ALSO SELECTED; A POINT THAT WE DEDUCED SOMETIME LATER. AT ONE POINT; I HAD DIRECTED THE FO TO ASK FOR DIRECT TO DRUZZ; WHICH WAS REFUSED BY THE CONTROLLER DUE TO SPACING. IT WAS ABOUT THIS TIME THAT WE GOT OURSELVES SORTED OUT. WE FINALLY GOT ESL BACK ONTO THE MAP AND AS DRUZZ WAS THE NEXT FIX (AFTER CANCELING EACH OTHER OUT AT LEAST ONCE); AND AT LEAST WE HAD A COURSE TO GO TO. THIS TOOK A LITTLE LONGER; BECAUSE WE WERE BOTH 'IN THE BOX' I SHOULD HAVE BEEN FLYING THE AIRPLANE AND ALLOWED THE FO TO HANDLE THE PROGRAMMING; A THOUGHT THAT OCCURRED TO ME AFTER WE LANDED AND CRITIQUED WHAT HAD HAPPENED TO US. WE WERE BOTH TASK SATURATED FOR A COUPLE OF MINUTES; THE FO WITH COMMUNICATIONS; CHECKLISTS AND CHANGES; AND ME WITH CLEARANCE COMPLIANCE; BRIEFINGS AND PLANNING. WE REESTABLISHED OURSELVES ONTO THE ARRIVAL PRIOR TO ESL BY SELECTING THE ILS RWY 19R; WHICH IN TURN; ALLOWED THE SHNON1 TO BE DISPLAYED AND LINE SELECTABLE. WE ALSO COMPLIED WITH THE SPEED AND ALTITUDE CLEARANCES (SOMEWHAT OF A MIRACLE; I MUST SAY!) UPON CONTACT WITH POTOMAC APPROACH; WE WERE TOLD TO EXPECT A VISUAL TO RWY 12. AT THIS POINT; WE HAD SPECULATED THAT THE SOURCE OF OUR PROBLEM WAS MY SELECTION OF THE ILS RWY 12 DURING THE INITIAL PART OF THE DESCENT. WE NOW SELECTED RWY 12 AFTER BEING TOLD TO EXPECT IT; BUT DID NOT EXECUTE IT; AS WE WERE STILL ON THE ARRIVAL ROUTING AND WE DID NOT CARE TO HAVE A REPEAT OF PRECEDING EVENTS. WE MADE THE SOUTHERLY TURN AT RAZZZ AT EXACTLY THE SAME TIME WE WERE GIVEN A POTOMAC FREQUENCY CHANGE. WE RELAYED TO THE NEW CONTROLLER THAT WE WERE STILL ON THE DEPICTED ROUTING. HE GAVE US A TURN BACK TO 020 DEGS (A 140 DEGREE CHANGE IN DIRECTION) AND CLEARED US TO INTERCEPT THE LOCALIZER. WE THEN EXECUTED THE ILS RWY 12 IN THE FMC AND SURE ENOUGH; ALL OF THE REMAINING SHNON1 DISAPPEARED. WE THEN EXTENDED THE FINAL FIX AND FLEW THE REST OF THE PROCEDURE IN ACCORDANCE WITH SOPS. SOME CONFUSION CONTINUED AS WE DID NOT RECEIVE A HAND OFF TO TOWER. THE FO SWITCHED TO TOWER AT ABOUT 1500 FT AGL AND WE WERE CLEAREDTO LAND ON RWY 19R. THE FO QUERIED THE CONTROLLER TO ESTABLISH THAT WE WERE IN FACT CLEARED TO LAND ON RWY 12; WHICH WAS CONFIRMED BY THE CONTROLLER. AFTER LANDING; THE FO ESTABLISHED THAT WE COULD 'ROLL TO THE END;' THEN LET THE CONTROLLER KNOW WE WOULD BE SWITCHING TO GROUND AS WE EXITED THE RUNWAY; AS WE WERE NOT DIRECTED TO DO SO. THESE ERRORS LEAD ME TO BELIEVE THAT THERE WAS SOME CONFUSION OR LACK OF COORDINATION BOTH IN THE TRACON AND THE TOWER FACILITIES AS WELL. QUESTIONS: AFTER REVIEW OF THE RNAV ARRIVAL (IN THE COMFORT OF MY OWN MONDAY MORNING QUARTERBACK CHAIR); I SEE THAT UNDER THE ROUTING AND LANDING DESCRIPTION BOXES; THE PROCEDURE IS SPECIFIC TO THE NORTH/SOUTH RUNWAYS. IF; AS IN OUR CASE; THE RUNWAY IS ULTIMATELY NOT THE ONE THAT WAS PLANNED FOR; WHAT IS TO PREVENT THE SITUATION FROM DEVELOPING AS I HAVE DESCRIBED ABOVE? IF; FOR INSTANCE; WE HAD RECEIVED A NEW ATIS THAT ALERTED US TO THE POSSIBILITY OF LANDING ON A RUNWAY NOT TIED TO THE ARRIVAL MUCH EARLIER IN THE FLIGHT; WOULD WE BE EXPECTED TO WORK OUT A NEW CLEARANCE WITH ATC SO THAT WE WOULD BE ABLE TO PROGRAM AN ARRIVAL; AND A RUNWAY; WITH THE SORT OF DISCONTINUITY WE ARE EXPECTING TO SEE BETWEEN THE END OF THE STAR AND THE INITIAL APPROACH FIX? HOW MANY OF THE NEW RNAV ARRIVALS WILL DISAPPEAR? IF A DIFFERENT RUNWAY IS SELECTED FROM THE FMC AND EXECUTED; IS THIS AN ANOMALY IN OUR FMCS AND IF SO; IS THERE A CHANGE COMING? IF NOT; IS THERE ADEQUATE COORDINATION BETWEEN OUR DISPATCH AND THE TRACON? FINALLY; ONE OF THE MAIN PURPOSES OF ANY RNAV PROCEDURE IS TO ALLOW AIRPLANES WITH FMCS TO FLY IN SUCH A MANNER THAT IT IS EFFICIENT; BOTH IN TERMS OF PILOT/CONTROLLER WORKLOAD AND FUEL/EMISSIONS. WHY THEN; WERE WE GIVEN CLEARANCES THAT MOSTLY MIRRORED THE OPERATIONAL CONSTRAINTS OF THE PROCEDURE; BUT REQUIRED MUCH EXTRA PROGRAMMING AND COMMUNICATIONS ON BOTH THE PART OF THE CONTROLLER AND PILOTS? THE POSSIBILITY FOR ERRORS DRAMATICALLY INCREASES AND IN OUR CASE; WE WERE LEFT WITHOUT ANY SA FOR A COUPLE OF MINUTES UNTIL WE GOT OUR FMC GENERATED MAP BACK. THAT IS ALL WE HAD; AS ONE CANNOT BACK UP AN RNAV PROCEDURE WITH RAW DATA. LESSONS LEARNED: HOW WONDERFUL IT IS TO HAVE A COMPETENT AND CAPABLE FO!! SECOND; SIT BACK; FLY THE AIRPLANE AND LET HIM DO HIS COMPETENT THINGS! HE SUGGESTED FILING THESE REPORTS AND ALSO FOLLOWING UP WITH THE TRACON. MY INPUT TO THIS WAS TO TELL HIM THAT THE REPORTS WERE AN EXCELLENT IDEA.

Data retrieved from NASA's ASRS site as of May 2009 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.