Altitude deviation. Crossing restriction not met.

Attributes
ACN	139395
Time
Date	199003
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : osi
State Reference	CA
Altitude	msl bound lower : 8000 msl bound upper : 18000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 155 flight time total : 18000
ASRS Report	139395
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot altitude deviation : crossing restriction not met other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance none taken : unable
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation Inter Facility Coordination Failure

Narrative:

Our flight was originally cleared to 18000' (FL180) and anticipate to cross a point southwest of woodside VOR at 8000' point only defined as 25 NM southwest of woodside. When about 40 NM nnw of woodside I asked controller how far we had to run (how many mi) to this point. He replied by saying he needed us farther out and for us to proceed direct to pyrat to cross pyrat at 8000' and then proceed direct to woodside VOR and maintain 8000'. By the time we found pyrat on our charts (this was first time it was mentioned) and programmed our INS and VOR's to display this position we had already passed it. He gave us this clearance probably within 6-8 mi of pyrat. Turning to the VOR on the pyrat right we advised that we would be unable to make the crossing altitude and asked if he wished us to continue direct to woodside. He said for us to make one 360 to left and midway through this maneuver he gave us a rollout heading of 120 degree. We were descending at maximum rate with speed brakes as soon as he gave us clearance. The clearance he gave direct pyrat to cross at 8000' was an impossible one for us to make considering our altitude and proximity; also, we do not have the capacity to go direct to a point unless we enter it into our INS which after an ocean crossing is not accurate enough for terminal environment. Our INS error on arrival was 14 mi, 21 mi, and 2 mi. A glass cockpit aircraft might have this immediate capability but our vintage equipment does not!

Original NASA ASRS Text

Title: ALT DEVIATION. CROSSING RESTRICTION NOT MET.

Narrative: OUR FLT WAS ORIGINALLY CLRED TO 18000' (FL180) AND ANTICIPATE TO CROSS A POINT SW OF WOODSIDE VOR AT 8000' POINT ONLY DEFINED AS 25 NM SW OF WOODSIDE. WHEN ABOUT 40 NM NNW OF WOODSIDE I ASKED CTLR HOW FAR WE HAD TO RUN (HOW MANY MI) TO THIS POINT. HE REPLIED BY SAYING HE NEEDED US FARTHER OUT AND FOR US TO PROCEED DIRECT TO PYRAT TO CROSS PYRAT AT 8000' AND THEN PROCEED DIRECT TO WOODSIDE VOR AND MAINTAIN 8000'. BY THE TIME WE FOUND PYRAT ON OUR CHARTS (THIS WAS FIRST TIME IT WAS MENTIONED) AND PROGRAMMED OUR INS AND VOR'S TO DISPLAY THIS POS WE HAD ALREADY PASSED IT. HE GAVE US THIS CLRNC PROBABLY WITHIN 6-8 MI OF PYRAT. TURNING TO THE VOR ON THE PYRAT R WE ADVISED THAT WE WOULD BE UNABLE TO MAKE THE XING ALT AND ASKED IF HE WISHED US TO CONTINUE DIRECT TO WOODSIDE. HE SAID FOR US TO MAKE ONE 360 TO L AND MIDWAY THROUGH THIS MANEUVER HE GAVE US A ROLLOUT HDG OF 120 DEG. WE WERE DSNDING AT MAX RATE WITH SPD BRAKES AS SOON AS HE GAVE US CLRNC. THE CLRNC HE GAVE DIRECT PYRAT TO CROSS AT 8000' WAS AN IMPOSSIBLE ONE FOR US TO MAKE CONSIDERING OUR ALT AND PROX; ALSO, WE DO NOT HAVE THE CAPACITY TO GO DIRECT TO A POINT UNLESS WE ENTER IT INTO OUR INS WHICH AFTER AN OCEAN XING IS NOT ACCURATE ENOUGH FOR TERMINAL ENVIRONMENT. OUR INS ERROR ON ARR WAS 14 MI, 21 MI, AND 2 MI. A GLASS COCKPIT ACFT MIGHT HAVE THIS IMMEDIATE CAPABILITY BUT OUR VINTAGE EQUIPMENT DOES NOT!

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.