|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||airport : sit.airport|
|Altitude||msl single value : 2000|
|Controlling Facilities||artcc : zan.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||Commercial Fixed Wing|
|Operating Under FAR Part||Part 121|
|Navigation In Use||other|
|Flight Phase||descent : approach|
|Route In Use||approach : instrument non precision|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : multi engine|
pilot : atp
pilot : cfi
pilot : commercial
pilot : instrument
|Experience||flight time last 90 days : 146|
flight time total : 5650
flight time type : 2000
|Anomaly||aircraft equipment problem : less severe|
non adherence : far
|Independent Detector||other flight crewa|
|Resolutory Action||none taken : anomaly accepted|
|Primary Problem||Navigational Facility|
We departed on a scheduled flight bound for sitka; ak's rocky gutierrez airport (pasi). The flight proceeded as filed at 12000 ft MSL via V311. As was the crew's custom on this route; once established nwbound on V311; the flight director was coupled to the GPS which was following a stored flight plan describing the route. Also in accord with the crew's custom; ann and bka VOR's were used for backup navigation information by way of the aircraft's HSI's. All through the flight; both ann and bka VOR's provided navigation information that conformed to the navigation information depicted by: 1) the aircraft's GPS (moving map screen). 2) the ermi's which were pointing to RNAV waypoints on the airway. 3) the flight director coupled to the GPS. Well east of the charted VOR change-over-point on V311; both crew members switched from the trailing ann VOR to the bka VOR which lay ahead on the course. Since the VOR was being used only for backup navigation information; the crew did not 'identify' the bka VOR by way of the morse code identifier. Some distance east of flips intersection on V311; as a matter of planning convenience for both the flight crew and anchorage ARTCC; the crew queried anchorage ARTCC as to the current sitka WX. This query has become customary on this route because the pasi ATIS is not readable from 12000 ft MSL until the aircraft is close enough to the airport so as to leave inadequate time for optimal approach planning and briefing. Zan relayed the then-current pasi WX to the crew who subsequently made the decision to fly the pasi VOR-C approach into visual conditions and to then enter a right downwind pattern for runway 11. Center was so advised. Shortly thereafter; zan cleared the flight for the VOR-C approach to pasi. The zan controller made no mention of any NAVAID outage or any associated NOTAMS. The crew completed the approach briefing along with the descent and approach checklists; and somewhere in the vicinity of flips intersection began the descent along V311 to join the published 10 NM DME-arc of the VOR-C approach. Joining the approach's DME-arc; the crew switched the flight director from GPS-RNAV mode to VOR mode and the captain descended from the last en route altitude to 4000 ft MSL as depicted on the approach. Passing through the 120 degree bka VOR radial; the captain began the descent to the next step-down altitude of 2000 ft MSL. At approximately the time that the airplane arrived at 2000 ft MSL; the first officer was listening to the ATIS and reported to the captain that the bka VOR was NOTAM'ed OTS. Both crew members then confirmed the absence of the morse code identifier on the bka VOR frequency of 113.8 MHZ. Given that the RMI and CDI indications of the VOR signal appeared to be normal; and given that the crew had followed the company's policy of creating a GPS overlay of the final approach course as a backup to the VOR data; and further given that the GPS moving-map and the ermi's data were congruent with the VOR data; the captain elected to continue the approach inbound to the bka VOR. In the captain's opinion; commencing an unpublished escape procedure in the vicinity of mountainous terrain presented an unacceptable alternative to the safe procedure of continuing on to the bka VOR via the published VOR approach utilizing both VOR and GPS data for navigation. Prior to the FAF (the bka VOR) the aircraft entered visual conditions with the sitka airport in sight. The arrival concluded by way of a normal visual traffic pattern and landing on runway 11. The factors which contributed to this event are as follows: 1) within the list of NOTAMS accompanying the flight release provided the flight crew by the air carrier's dispatch office; there was no information relating to the bka VOR being OTS. 2) the topography of the sitka area and; presumably; the ATIS transmitter's antenna location; combine to restrict the ATIS signal's range of reception from altitudes around and below that at which the subject flight was flown. With regard to this air carrier's operations into sitka; a custom has spontaneously evolved such that; while the flight is still in the en route phase; in order to promote efficient planning and air traffic flow; on virtually every flight; either the flight crew or the anchorage ARTCC controller will initiate a query to the other regarding the sitka WX. This leads to the sitka WX being provided to the flight crew by the controller. This; in-turn; and in combination with the ATIS signal range limitations; prompts the crew to obtain the sitka ATIS later in the arrival process than they otherwise might. In this case the actual ATIS containing the NOTAM regarding the VOR was not obtained until the approach was underway. 3) the anchorage ARTCC controller did not advise the crew of the OTS VOR and cleared the flight for the VOR-C approach. 4) the flow of events brought the crew to listen for the bka VOR's morse code identifier later than they should have. 5) crew complacency too was a factor in this event. Having flown this approach many times; the crew was very familiar with the 'expected' sequence of events; all of which were normal; save the absence of the bka VOR's morse code identifier. Corrective actions: from the flight crew's perspective the following corrective actions have been or will be accomplished: 1) the crew has resolved to scrupulously tune and identify all VOR's; even when a VOR in question is not being used as the primary NAVAID. 2) the crew will alter their routine to ensure that the sitka ATIS is obtained as soon as the radio signal becomes intelligible. 3) the crew recognizes that complacency played a significant role in this event and resolves to fight this dangerous human tendency. 4) the crew will contact the air carrier's dispatch to determine why the NOTAM regarding the bka VOR being OTS was not contained in the flight release packet. 5) the captain will contact sitka FSS and formally make the suggestion that the sitka ATIS system be reengineered so as to provide greater signal range for aircraft flying low altitude rtes in the area.
Original NASA ASRS Text
Title: AT43 FLIES ENTIRE FLT ON GPS BACKED UP BY VOR MONITORING INCLUDING BKA. ONLY AFTER INITIATING VOR-C APCH TO PASI DO THEY LEARN THAT BKA VORTAC IS NOTAMED UNSERVICEABLE.
Narrative: WE DEPARTED ON A SCHEDULED FLT BOUND FOR SITKA; AK'S ROCKY GUTIERREZ ARPT (PASI). THE FLT PROCEEDED AS FILED AT 12000 FT MSL VIA V311. AS WAS THE CREW'S CUSTOM ON THIS RTE; ONCE ESTABLISHED NWBOUND ON V311; THE FLT DIRECTOR WAS COUPLED TO THE GPS WHICH WAS FOLLOWING A STORED FLT PLAN DESCRIBING THE RTE. ALSO IN ACCORD WITH THE CREW'S CUSTOM; ANN AND BKA VOR'S WERE USED FOR BACKUP NAV INFO BY WAY OF THE ACFT'S HSI'S. ALL THROUGH THE FLT; BOTH ANN AND BKA VOR'S PROVIDED NAV INFO THAT CONFORMED TO THE NAV INFO DEPICTED BY: 1) THE ACFT'S GPS (MOVING MAP SCREEN). 2) THE ERMI'S WHICH WERE POINTING TO RNAV WAYPOINTS ON THE AIRWAY. 3) THE FLT DIRECTOR COUPLED TO THE GPS. WELL E OF THE CHARTED VOR CHANGE-OVER-POINT ON V311; BOTH CREW MEMBERS SWITCHED FROM THE TRAILING ANN VOR TO THE BKA VOR WHICH LAY AHEAD ON THE COURSE. SINCE THE VOR WAS BEING USED ONLY FOR BACKUP NAV INFO; THE CREW DID NOT 'IDENT' THE BKA VOR BY WAY OF THE MORSE CODE IDENTIFIER. SOME DISTANCE E OF FLIPS INTXN ON V311; AS A MATTER OF PLANNING CONVENIENCE FOR BOTH THE FLT CREW AND ANCHORAGE ARTCC; THE CREW QUERIED ANCHORAGE ARTCC AS TO THE CURRENT SITKA WX. THIS QUERY HAS BECOME CUSTOMARY ON THIS RTE BECAUSE THE PASI ATIS IS NOT READABLE FROM 12000 FT MSL UNTIL THE ACFT IS CLOSE ENOUGH TO THE ARPT SO AS TO LEAVE INADEQUATE TIME FOR OPTIMAL APCH PLANNING AND BRIEFING. ZAN RELAYED THE THEN-CURRENT PASI WX TO THE CREW WHO SUBSEQUENTLY MADE THE DECISION TO FLY THE PASI VOR-C APCH INTO VISUAL CONDITIONS AND TO THEN ENTER A R DOWNWIND PATTERN FOR RWY 11. CTR WAS SO ADVISED. SHORTLY THEREAFTER; ZAN CLRED THE FLT FOR THE VOR-C APCH TO PASI. THE ZAN CTLR MADE NO MENTION OF ANY NAVAID OUTAGE OR ANY ASSOCIATED NOTAMS. THE CREW COMPLETED THE APCH BRIEFING ALONG WITH THE DSCNT AND APCH CHKLISTS; AND SOMEWHERE IN THE VICINITY OF FLIPS INTXN BEGAN THE DSCNT ALONG V311 TO JOIN THE PUBLISHED 10 NM DME-ARC OF THE VOR-C APCH. JOINING THE APCH'S DME-ARC; THE CREW SWITCHED THE FLT DIRECTOR FROM GPS-RNAV MODE TO VOR MODE AND THE CAPT DSNDED FROM THE LAST ENRTE ALT TO 4000 FT MSL AS DEPICTED ON THE APCH. PASSING THROUGH THE 120 DEG BKA VOR RADIAL; THE CAPT BEGAN THE DSCNT TO THE NEXT STEP-DOWN ALT OF 2000 FT MSL. AT APPROX THE TIME THAT THE AIRPLANE ARRIVED AT 2000 FT MSL; THE FO WAS LISTENING TO THE ATIS AND RPTED TO THE CAPT THAT THE BKA VOR WAS NOTAM'ED OTS. BOTH CREW MEMBERS THEN CONFIRMED THE ABSENCE OF THE MORSE CODE IDENTIFIER ON THE BKA VOR FREQ OF 113.8 MHZ. GIVEN THAT THE RMI AND CDI INDICATIONS OF THE VOR SIGNAL APPEARED TO BE NORMAL; AND GIVEN THAT THE CREW HAD FOLLOWED THE COMPANY'S POLICY OF CREATING A GPS OVERLAY OF THE FINAL APCH COURSE AS A BACKUP TO THE VOR DATA; AND FURTHER GIVEN THAT THE GPS MOVING-MAP AND THE ERMI'S DATA WERE CONGRUENT WITH THE VOR DATA; THE CAPT ELECTED TO CONTINUE THE APCH INBOUND TO THE BKA VOR. IN THE CAPT'S OPINION; COMMENCING AN UNPUBLISHED ESCAPE PROC IN THE VICINITY OF MOUNTAINOUS TERRAIN PRESENTED AN UNACCEPTABLE ALTERNATIVE TO THE SAFE PROC OF CONTINUING ON TO THE BKA VOR VIA THE PUBLISHED VOR APCH UTILIZING BOTH VOR AND GPS DATA FOR NAV. PRIOR TO THE FAF (THE BKA VOR) THE ACFT ENTERED VISUAL CONDITIONS WITH THE SITKA ARPT IN SIGHT. THE ARR CONCLUDED BY WAY OF A NORMAL VISUAL TFC PATTERN AND LNDG ON RWY 11. THE FACTORS WHICH CONTRIBUTED TO THIS EVENT ARE AS FOLLOWS: 1) WITHIN THE LIST OF NOTAMS ACCOMPANYING THE FLT RELEASE PROVIDED THE FLT CREW BY THE ACR'S DISPATCH OFFICE; THERE WAS NO INFO RELATING TO THE BKA VOR BEING OTS. 2) THE TOPOGRAPHY OF THE SITKA AREA AND; PRESUMABLY; THE ATIS XMITTER'S ANTENNA LOCATION; COMBINE TO RESTRICT THE ATIS SIGNAL'S RANGE OF RECEPTION FROM ALTS AROUND AND BELOW THAT AT WHICH THE SUBJECT FLT WAS FLOWN. WITH REGARD TO THIS ACR'S OPS INTO SITKA; A CUSTOM HAS SPONTANEOUSLY EVOLVED SUCH THAT; WHILE THE FLT IS STILL IN THE ENRTE PHASE; IN ORDER TO PROMOTE EFFICIENT PLANNING AND AIR TFC FLOW; ON VIRTUALLY EVERY FLT; EITHER THE FLT CREW OR THE ANCHORAGE ARTCC CTLR WILL INITIATE A QUERY TO THE OTHER REGARDING THE SITKA WX. THIS LEADS TO THE SITKA WX BEING PROVIDED TO THE FLT CREW BY THE CTLR. THIS; IN-TURN; AND IN COMBINATION WITH THE ATIS SIGNAL RANGE LIMITATIONS; PROMPTS THE CREW TO OBTAIN THE SITKA ATIS LATER IN THE ARR PROCESS THAN THEY OTHERWISE MIGHT. IN THIS CASE THE ACTUAL ATIS CONTAINING THE NOTAM REGARDING THE VOR WAS NOT OBTAINED UNTIL THE APCH WAS UNDERWAY. 3) THE ANCHORAGE ARTCC CTLR DID NOT ADVISE THE CREW OF THE OTS VOR AND CLRED THE FLT FOR THE VOR-C APCH. 4) THE FLOW OF EVENTS BROUGHT THE CREW TO LISTEN FOR THE BKA VOR'S MORSE CODE IDENTIFIER LATER THAN THEY SHOULD HAVE. 5) CREW COMPLACENCY TOO WAS A FACTOR IN THIS EVENT. HAVING FLOWN THIS APCH MANY TIMES; THE CREW WAS VERY FAMILIAR WITH THE 'EXPECTED' SEQUENCE OF EVENTS; ALL OF WHICH WERE NORMAL; SAVE THE ABSENCE OF THE BKA VOR'S MORSE CODE IDENTIFIER. CORRECTIVE ACTIONS: FROM THE FLT CREW'S PERSPECTIVE THE FOLLOWING CORRECTIVE ACTIONS HAVE BEEN OR WILL BE ACCOMPLISHED: 1) THE CREW HAS RESOLVED TO SCRUPULOUSLY TUNE AND IDENT ALL VOR'S; EVEN WHEN A VOR IN QUESTION IS NOT BEING USED AS THE PRIMARY NAVAID. 2) THE CREW WILL ALTER THEIR ROUTINE TO ENSURE THAT THE SITKA ATIS IS OBTAINED AS SOON AS THE RADIO SIGNAL BECOMES INTELLIGIBLE. 3) THE CREW RECOGNIZES THAT COMPLACENCY PLAYED A SIGNIFICANT ROLE IN THIS EVENT AND RESOLVES TO FIGHT THIS DANGEROUS HUMAN TENDENCY. 4) THE CREW WILL CONTACT THE ACR'S DISPATCH TO DETERMINE WHY THE NOTAM REGARDING THE BKA VOR BEING OTS WAS NOT CONTAINED IN THE FLT RELEASE PACKET. 5) THE CAPT WILL CONTACT SITKA FSS AND FORMALLY MAKE THE SUGGESTION THAT THE SITKA ATIS SYS BE REENGINEERED SO AS TO PROVIDE GREATER SIGNAL RANGE FOR ACFT FLYING LOW ALT RTES IN THE AREA.
Data retrieved from NASA's ASRS site as of January 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.