An air carrier widebody transport complains about having 2 nmacs in 5 mins.

Attributes
ACN	264210
Time
Date	199402
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : vxv
State Reference	TN
Altitude	msl bound lower : 28000 msl bound upper : 29400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other cruise 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 : 240 flight time total : 12000
ASRS Report	264210
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude conflict : nmac non adherence : required legal separation non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 350
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

2 near misses in space of 5 mins. TCASII alert from oncoming traffic. Showed 800 plus at 6 mi, then 500 ft separation in evasion maneuver overhead. Second target 10 mi behind, same sequence except missed by 300 ft. We were at assigned altitude FL280. Other aircraft on descent into charlotte, nc. Controller says they were assigned FL290 and showed level. One of 3 possible causes: 1) TCASII error, 2) controller error, 3) pilot error. Supplemental information from acn 264451: we noted, on our TCASII display, traffic opposite direction, 600 ft below us and climbing. We believe the other aircraft missed his assigned level off altitude of FL280. Supplemental information from acn 263800: we continued to watch him until he got within 500 ft vertically from out altitude. At this time I asked center about this traffic. TCASII told us to climb. We started an immediate climb to 29400 ft. We believe intruding air carrier widebody transport forgot to set its altimeter to 29.92 which caused it to be 500 ft higher than they were supposed to be.

Original NASA ASRS Text

Title: AN ACR WDB COMPLAINS ABOUT HAVING 2 NMACS IN 5 MINS.

Narrative: 2 NEAR MISSES IN SPACE OF 5 MINS. TCASII ALERT FROM ONCOMING TFC. SHOWED 800 PLUS AT 6 MI, THEN 500 FT SEPARATION IN EVASION MANEUVER OVERHEAD. SECOND TARGET 10 MI BEHIND, SAME SEQUENCE EXCEPT MISSED BY 300 FT. WE WERE AT ASSIGNED ALT FL280. OTHER ACFT ON DSCNT INTO CHARLOTTE, NC. CTLR SAYS THEY WERE ASSIGNED FL290 AND SHOWED LEVEL. ONE OF 3 POSSIBLE CAUSES: 1) TCASII ERROR, 2) CTLR ERROR, 3) PLT ERROR. SUPPLEMENTAL INFO FROM ACN 264451: WE NOTED, ON OUR TCASII DISPLAY, TFC OPPOSITE DIRECTION, 600 FT BELOW US AND CLBING. WE BELIEVE THE OTHER ACFT MISSED HIS ASSIGNED LEVEL OFF ALT OF FL280. SUPPLEMENTAL INFO FROM ACN 263800: WE CONTINUED TO WATCH HIM UNTIL HE GOT WITHIN 500 FT VERTLY FROM OUT ALT. AT THIS TIME I ASKED CTR ABOUT THIS TFC. TCASII TOLD US TO CLB. WE STARTED AN IMMEDIATE CLB TO 29400 FT. WE BELIEVE INTRUDING ACR WDB FORGOT TO SET ITS ALTIMETER TO 29.92 WHICH CAUSED IT TO BE 500 FT HIGHER THAN THEY WERE SUPPOSED TO BE.

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.