Altitude deviation. Crossing restriction not met.

Attributes
ACN	127804
Time
Date	198911
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : oxi
State Reference	IN
Altitude	msl bound lower : 9000 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other descent other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 240 flight time total : 4500 flight time type : 2200
ASRS Report	127804
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

ZAU gave us crossing restriction of 9000' over oxi VOR. We were level at 12000', about 35 DME east. Approximately 29 DME we were handed off to another center controller. This controller gave us an assigned heading to intercept mdw 31L localizer. We assumed that this deleted the crossing restriction since we would not cross over the fix. When we were approximately over oxi VOR, which we were no longer navigating to. Center asked if we had been given a crossing altitude of 9000' over oxi. I replied we were on our way down (caught off guard, confused momentarily), to which he replied that we were currently over oxi. At this point I wanted to explain to him what we were doing, but from reading many industry publications about sticking your foot in your mouth over ATC frequency on tape, decided to say nothing at this point until being able to think about situation. We definitely should have started down earlier, but with oxi VOR not in navs, our relationship to oxi was not in our minds. When we handed off to second controller and called level 12000' (not stating crossing altitude), controller should have stated so at this time.

Original NASA ASRS Text

Title: ALT DEVIATION. CROSSING RESTRICTION NOT MET.

Narrative: ZAU GAVE US XING RESTRICTION OF 9000' OVER OXI VOR. WE WERE LEVEL AT 12000', ABOUT 35 DME E. APPROX 29 DME WE WERE HANDED OFF TO ANOTHER CENTER CTLR. THIS CTLR GAVE US AN ASSIGNED HDG TO INTERCEPT MDW 31L LOC. WE ASSUMED THAT THIS DELETED THE XING RESTRICTION SINCE WE WOULD NOT CROSS OVER THE FIX. WHEN WE WERE APPROX OVER OXI VOR, WHICH WE WERE NO LONGER NAVIGATING TO. CENTER ASKED IF WE HAD BEEN GIVEN A XING ALT OF 9000' OVER OXI. I REPLIED WE WERE ON OUR WAY DOWN (CAUGHT OFF GUARD, CONFUSED MOMENTARILY), TO WHICH HE REPLIED THAT WE WERE CURRENTLY OVER OXI. AT THIS POINT I WANTED TO EXPLAIN TO HIM WHAT WE WERE DOING, BUT FROM READING MANY INDUSTRY PUBLICATIONS ABOUT STICKING YOUR FOOT IN YOUR MOUTH OVER ATC FREQ ON TAPE, DECIDED TO SAY NOTHING AT THIS POINT UNTIL BEING ABLE TO THINK ABOUT SITUATION. WE DEFINITELY SHOULD HAVE STARTED DOWN EARLIER, BUT WITH OXI VOR NOT IN NAVS, OUR RELATIONSHIP TO OXI WAS NOT IN OUR MINDS. WHEN WE HANDED OFF TO SECOND CTLR AND CALLED LEVEL 12000' (NOT STATING XING ALT), CTLR SHOULD HAVE STATED SO AT THIS TIME.

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.