Air carrier aircraft at FL410 became confused by ZOB whether to cross a fix 15 mi west or 15 mi east at FL270. Crew claims the center verified east at FL270. Approaching the fix, the air carrier received a TCASII RA on opposite direction traffic at FL350.

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Attributes
ACN	401218
Time
Date	199805
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : slt
State Reference	PA
Altitude	msl bound lower : 36000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zob
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	other other : other pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 1500
ASRS Report	401218
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	other other : other pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 90 flight time total : 7000 flight time type : 90
ASRS Report	401220
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 1000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Ord-ewr cruising at FL410. We received clearance to cross 15 mi west slt at FL270, and captain read that back and I verified by pointing at FL270 on MCP. We realized that was just 5 mi away and captain verified with ATC, 15 mi west slt at FL270. They corrected us 15 mi east slt at FL270, and captain read back 15 mi east slt, FL270. We began our descent to make the restr. Descending through FL360, center asked if we were level at FL370, and we realized there must have been a mistake. I turned the autoplt off and climbed back to FL370. At the same time, we received 1 RA 'traffic' callout, and center gave us a left 45 degree turn. We had traffic below at FL350. No near miss occurred. The ATC frequency was busy. Our incorrect readback of FL270 was not caught by the controller 3 times on our readbacks (or possibly we were given FL270 by mistake from ATC. Both pilots thought we heard FL270) and there was confusion about which side of slt VOR for the crossing restr. This was the end of a long duty day (14 hours) and WX delays at both ord and ewr at minimums. After the event we were given clearance to FL240 I believe.

Original NASA ASRS Text

Title: ACR ACFT AT FL410 BECAME CONFUSED BY ZOB WHETHER TO CROSS A FIX 15 MI W OR 15 MI E AT FL270. CREW CLAIMS THE CTR VERIFIED E AT FL270. APCHING THE FIX, THE ACR RECEIVED A TCASII RA ON OPPOSITE DIRECTION TFC AT FL350.

Narrative: ORD-EWR CRUISING AT FL410. WE RECEIVED CLRNC TO CROSS 15 MI W SLT AT FL270, AND CAPT READ THAT BACK AND I VERIFIED BY POINTING AT FL270 ON MCP. WE REALIZED THAT WAS JUST 5 MI AWAY AND CAPT VERIFIED WITH ATC, 15 MI W SLT AT FL270. THEY CORRECTED US 15 MI E SLT AT FL270, AND CAPT READ BACK 15 MI E SLT, FL270. WE BEGAN OUR DSCNT TO MAKE THE RESTR. DSNDING THROUGH FL360, CTR ASKED IF WE WERE LEVEL AT FL370, AND WE REALIZED THERE MUST HAVE BEEN A MISTAKE. I TURNED THE AUTOPLT OFF AND CLBED BACK TO FL370. AT THE SAME TIME, WE RECEIVED 1 RA 'TFC' CALLOUT, AND CTR GAVE US A L 45 DEG TURN. WE HAD TFC BELOW AT FL350. NO NEAR MISS OCCURRED. THE ATC FREQ WAS BUSY. OUR INCORRECT READBACK OF FL270 WAS NOT CAUGHT BY THE CTLR 3 TIMES ON OUR READBACKS (OR POSSIBLY WE WERE GIVEN FL270 BY MISTAKE FROM ATC. BOTH PLTS THOUGHT WE HEARD FL270) AND THERE WAS CONFUSION ABOUT WHICH SIDE OF SLT VOR FOR THE XING RESTR. THIS WAS THE END OF A LONG DUTY DAY (14 HRS) AND WX DELAYS AT BOTH ORD AND EWR AT MINIMUMS. AFTER THE EVENT WE WERE GIVEN CLRNC TO FL240 I BELIEVE.

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.