Narrative:

Scheduled air carrier passenger flight from bos to ord. Filed route: bos mht syr.... Predep: 'filed route: bos mht syr....' 'revised segment: none.' 'remarks: maintain 5000 ft, expect requested altitude 10 mins after takeoff, departure frequency 133.0, wylyy 1 departure, contact 121.65 when ready to push.' we anticipated receiving the 'logan 2' departure (vector), and in reviewing the pre departure clearance received by ACARS, we noted no 'revised segment,' but missed the wylyy 1 departure in the 'remarks' segment. The ground tracks of the 2 departures are nearly identical. The wylyy 1 does impose additional altitude and airspeed constraints, which did not play a part in this event, and normally would not. Shortly after takeoff, tower switched us over to departure control. Upon initial contact with departure, we were cleared direct to wylyy and 5000 ft. I replied that we would have to enter it into the FMS. He then just gave us a heading to wylyy and asked if we had been cleared via the wylyy 1. I told him that I thought not, but that we would check and get back to him. He stated that it presented no problem, but that they were having problems in general with departure clrncs with runway 27 takeoffs and wanted to know about our pre departure clearance. Once cleaned up and cleared to mht, I told the departure controller that we had overlooked the wylyy 1 clearance in the 'remarks' section of the pre departure clearance, but also noted that the 'revised segment' section indicated no revision to the filed route. He then switched us to ZBW. While proceeding direct to mht, using LNAV/FMS navigation guidance, at about 15000 ft and 300 KIAS, the FMS commanded about a 90 degree turn to transition to the direct route from mht to syr. Shortly after beginning the turn, center asked if we were over mht yet. We replied that we were using normal FMS guidance to accomplish the turn at mht, but that guidance was taking us about 6 NM southwest of mht. He then stated that our turn short of mht was reducing his desired separation on an aircraft ahead of us. We shallowed out the turn and no conflict occurred. 2 problem areas are highlighted in this report. 1) we missed the wylyy SID in the 'remarks' section of the pre departure clearance, in part because no revision was indicated in the 'revised segment' section. There seems to be a lack of standardization in this area. At some airports, an inserted SID is idented as a 'revised segment.' at others, it is included as a 'remark.' I recommend that sids be posted as a revision rather than a remark when not part of the filed route. 2) the LNAV/FMS turn guidance for a major course change at high speed in the A320 is not programmed to properly keep the airplane within far defined route width tolerance. I recommend that raw data guidance be used for any course change greater than 45-60 degrees. I further recommend that FMS programming logic be modified to provide proper guidance for this type of maneuvering to assure compliance with air route constraints.

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Original NASA ASRS Text

Title: PDC CONFUSION EXPOSES FLC TO DEV FROM CLRED DEP PROC.

Narrative: SCHEDULED ACR PAX FLT FROM BOS TO ORD. FILED RTE: BOS MHT SYR.... PREDEP: 'FILED RTE: BOS MHT SYR....' 'REVISED SEGMENT: NONE.' 'REMARKS: MAINTAIN 5000 FT, EXPECT REQUESTED ALT 10 MINS AFTER TKOF, DEP FREQ 133.0, WYLYY 1 DEP, CONTACT 121.65 WHEN READY TO PUSH.' WE ANTICIPATED RECEIVING THE 'LOGAN 2' DEP (VECTOR), AND IN REVIEWING THE PDC RECEIVED BY ACARS, WE NOTED NO 'REVISED SEGMENT,' BUT MISSED THE WYLYY 1 DEP IN THE 'REMARKS' SEGMENT. THE GND TRACKS OF THE 2 DEPS ARE NEARLY IDENTICAL. THE WYLYY 1 DOES IMPOSE ADDITIONAL ALT AND AIRSPD CONSTRAINTS, WHICH DID NOT PLAY A PART IN THIS EVENT, AND NORMALLY WOULD NOT. SHORTLY AFTER TKOF, TWR SWITCHED US OVER TO DEP CTL. UPON INITIAL CONTACT WITH DEP, WE WERE CLRED DIRECT TO WYLYY AND 5000 FT. I REPLIED THAT WE WOULD HAVE TO ENTER IT INTO THE FMS. HE THEN JUST GAVE US A HDG TO WYLYY AND ASKED IF WE HAD BEEN CLRED VIA THE WYLYY 1. I TOLD HIM THAT I THOUGHT NOT, BUT THAT WE WOULD CHK AND GET BACK TO HIM. HE STATED THAT IT PRESENTED NO PROB, BUT THAT THEY WERE HAVING PROBS IN GENERAL WITH DEP CLRNCS WITH RWY 27 TKOFS AND WANTED TO KNOW ABOUT OUR PDC. ONCE CLEANED UP AND CLRED TO MHT, I TOLD THE DEP CTLR THAT WE HAD OVERLOOKED THE WYLYY 1 CLRNC IN THE 'REMARKS' SECTION OF THE PDC, BUT ALSO NOTED THAT THE 'REVISED SEGMENT' SECTION INDICATED NO REVISION TO THE FILED RTE. HE THEN SWITCHED US TO ZBW. WHILE PROCEEDING DIRECT TO MHT, USING LNAV/FMS NAV GUIDANCE, AT ABOUT 15000 FT AND 300 KIAS, THE FMS COMMANDED ABOUT A 90 DEG TURN TO TRANSITION TO THE DIRECT RTE FROM MHT TO SYR. SHORTLY AFTER BEGINNING THE TURN, CTR ASKED IF WE WERE OVER MHT YET. WE REPLIED THAT WE WERE USING NORMAL FMS GUIDANCE TO ACCOMPLISH THE TURN AT MHT, BUT THAT GUIDANCE WAS TAKING US ABOUT 6 NM SW OF MHT. HE THEN STATED THAT OUR TURN SHORT OF MHT WAS REDUCING HIS DESIRED SEPARATION ON AN ACFT AHEAD OF US. WE SHALLOWED OUT THE TURN AND NO CONFLICT OCCURRED. 2 PROB AREAS ARE HIGHLIGHTED IN THIS RPT. 1) WE MISSED THE WYLYY SID IN THE 'REMARKS' SECTION OF THE PDC, IN PART BECAUSE NO REVISION WAS INDICATED IN THE 'REVISED SEGMENT' SECTION. THERE SEEMS TO BE A LACK OF STANDARDIZATION IN THIS AREA. AT SOME ARPTS, AN INSERTED SID IS IDENTED AS A 'REVISED SEGMENT.' AT OTHERS, IT IS INCLUDED AS A 'REMARK.' I RECOMMEND THAT SIDS BE POSTED AS A REVISION RATHER THAN A REMARK WHEN NOT PART OF THE FILED RTE. 2) THE LNAV/FMS TURN GUIDANCE FOR A MAJOR COURSE CHANGE AT HIGH SPD IN THE A320 IS NOT PROGRAMMED TO PROPERLY KEEP THE AIRPLANE WITHIN FAR DEFINED RTE WIDTH TOLERANCE. I RECOMMEND THAT RAW DATA GUIDANCE BE USED FOR ANY COURSE CHANGE GREATER THAN 45-60 DEGS. I FURTHER RECOMMEND THAT FMS PROGRAMMING LOGIC BE MODIFIED TO PROVIDE PROPER GUIDANCE FOR THIS TYPE OF MANEUVERING TO ASSURE COMPLIANCE WITH AIR RTE CONSTRAINTS.

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.