|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||atc facility : day|
|Altitude||msl bound lower : 24000|
msl bound upper : 26000
|Controlling Facilities||artcc : zid|
|Operator||common carrier : air carrier|
|Make Model Name||Widebody, Low Wing, 2 Turbojet Eng|
|Navigation In Use||Other |
|Flight Phase||descent other|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Experience||flight time last 90 days : 200|
flight time total : 11000
|Function||flight crew : first officer|
|Qualification||pilot : commercial|
pilot : instrument
|Anomaly||altitude deviation : crossing restriction not met|
non adherence : clearance
|Independent Detector||other flight crewa|
|Resolutory Action||controller : issued new clearance|
|Primary Problem||Flight Crew Human Performance|
|Air Traffic Incident||Pilot Deviation|
Ten mi north of dayton VOR we were cleared to cross 50 mi north of dayton at FL240. The copilot flying computed the distance from kline VOR since we had passed dayton. During the descent I recalculated the distance, this time from dayton, and found we were 47 mi north and passing FL260. I told the controller we would have difficulty making the restriction and asked if a turn was necessary. He asked what the reason was for use not starting down sooner. I informed him we had started down sooner but had not descended rapidly enough for the miscalculation. He turned us over to cle center. There was no conflict of traffic. I have experienced this crossing clearance several times and feel we would be better served with a clearance before dayton VOR. Our FMS computer input is more accurate for VOR down stream rather than putting in a VOR we have already passed. It takes a couple of extra entries to put in a VOR already passed and in some cases the bearing put in is not as accurate a reading as a down line VOR. In other words it is much more efficient and practical to keep all calculation based on downline vors rather than those we have already passed.
Original NASA ASRS Text
Title: FAILED TO MAKE CROSSING RESTRICTION.
Narrative: TEN MI N OF DAYTON VOR WE WERE CLRED TO CROSS 50 MI N OF DAYTON AT FL240. THE COPLT FLYING COMPUTED THE DISTANCE FROM KLINE VOR SINCE WE HAD PASSED DAYTON. DURING THE DSCNT I RECALCULATED THE DISTANCE, THIS TIME FROM DAYTON, AND FOUND WE WERE 47 MI N AND PASSING FL260. I TOLD THE CTLR WE WOULD HAVE DIFFICULTY MAKING THE RESTRICTION AND ASKED IF A TURN WAS NECESSARY. HE ASKED WHAT THE REASON WAS FOR USE NOT STARTING DOWN SOONER. I INFORMED HIM WE HAD STARTED DOWN SOONER BUT HAD NOT DSNDED RAPIDLY ENOUGH FOR THE MISCALCULATION. HE TURNED US OVER TO CLE CENTER. THERE WAS NO CONFLICT OF TFC. I HAVE EXPERIENCED THIS XING CLRNC SEVERAL TIMES AND FEEL WE WOULD BE BETTER SERVED WITH A CLRNC BEFORE DAYTON VOR. OUR FMS COMPUTER INPUT IS MORE ACCURATE FOR VOR DOWN STREAM RATHER THAN PUTTING IN A VOR WE HAVE ALREADY PASSED. IT TAKES A COUPLE OF EXTRA ENTRIES TO PUT IN A VOR ALREADY PASSED AND IN SOME CASES THE BEARING PUT IN IS NOT AS ACCURATE A READING AS A DOWN LINE VOR. IN OTHER WORDS IT IS MUCH MORE EFFICIENT AND PRACTICAL TO KEEP ALL CALCULATION BASED ON DOWNLINE VORS RATHER THAN THOSE WE HAVE ALREADY PASSED.
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.