Widebody transport maintaining FL310 overtakes mlt widebody transport same altitude.

Attributes
ACN	174768
Time
Date	199104
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : hil
State Reference	FO
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : direct enroute airway : a1
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Transport
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 16500 flight time type : 4500
ASRS Report	174768
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 230 flight time total : 25000 flight time type : 3500
ASRS Report	174649
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

While flying west along A1 (over saudi arabia) at FL310, we observed a mlt Y ahead of us and slightly to our right. We also picked him up on our WX radar. The flight conditions were VFR with a completely clear sky. We could not believe that another large aircraft was at our altitude (denial) over hail VOR. The mlt Y turned southwest for hlf while our clearance was direct to pasam with almost no course change. As the mlt Y passed from right to left in front of us, the PF eased our widebody transport X up approximately 300' to avoid the mlt's wash. The incident was reported to jeddah control (128.1), who turned us to 134.0, where it was resolved that the mlt Y had been incorrectly at FL310 due to an original misunderstanding of clearance. Our radar showed us passing within 2 mi of the mlt.

Original NASA ASRS Text

Title: WDB MAINTAINING FL310 OVERTAKES MLT WDB SAME ALT.

Narrative: WHILE FLYING W ALONG A1 (OVER SAUDI ARABIA) AT FL310, WE OBSERVED A MLT Y AHEAD OF US AND SLIGHTLY TO OUR RIGHT. WE ALSO PICKED HIM UP ON OUR WX RADAR. THE FLT CONDITIONS WERE VFR WITH A COMPLETELY CLR SKY. WE COULD NOT BELIEVE THAT ANOTHER LARGE ACFT WAS AT OUR ALT (DENIAL) OVER HAIL VOR. THE MLT Y TURNED SW FOR HLF WHILE OUR CLRNC WAS DIRECT TO PASAM WITH ALMOST NO COURSE CHANGE. AS THE MLT Y PASSED FROM RIGHT TO LEFT IN FRONT OF US, THE PF EASED OUR WDB X UP APPROX 300' TO AVOID THE MLT'S WASH. THE INCIDENT WAS RPTED TO JEDDAH CTL (128.1), WHO TURNED US TO 134.0, WHERE IT WAS RESOLVED THAT THE MLT Y HAD BEEN INCORRECTLY AT FL310 DUE TO AN ORIGINAL MISUNDERSTANDING OF CLRNC. OUR RADAR SHOWED US PASSING WITHIN 2 MI OF THE MLT.

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.