ARTCC radar controller climbed an LR31 to FL200 on a conflicting course with a C414 at FL210. The LR...

Attributes
ACN	375817
Time
Date	199707
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : rmg
State Reference	GA
Altitude	msl bound lower : 21000 msl bound upper : 21000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	general aviation : personal
Make Model Name	Chancellor 414A & C414
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Learjet 31
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 15
ASRS Report	375817
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	other
Consequence	faa : investigated
Miss Distance	horizontal : 23400 vertical : 600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation Operational Error

Narrative:

Small transport X was en route through the north departure (#38) sector at his cruise altitude of FL210. Light transport Y was climbing out of an atlanta satellite airport, possibly fulton county (fty). The controller on the sector was extremely busy with a mix of overflts and satellite/atl jet departures. To further complicate the situation, there was convective WX activity in the northern portion of the sector necessitating deviation from assigned routing by several aircraft. On initial contact, light transport Y was issued a climb clearance to FL190 which he acknowledged by reading back 'up to 1-9-0.' the rtes of flight put light transport Y and small transport X in confliction necessitating altitude separation. When subsequently climbed to FL200, light transport Y acknowledged with 'up to 2-ZERO.' light transport Y climbed to FL220 and lost separation with small transport X at approximately XA34 on jul/xa/97. When questioned by the controller, light transport Y stated that he was issued FL220 and acknowledged the altitude. Curiously, small transport X was also on the frequency and acknowledged each of his altitude clrncs with 'up to' the assigned altitude. I believe both of these aircraft are from the same company, possibly a company based in indianapolis. After reviewing the tapes, the controller was idented as primary in the error for failure to insure a proper readback. Far should be amended so as to require pilots to communicate via standard phraseology when acknowledging clrncs/control communications. Neither of these aircraft were equipped with TCASII. A large percentage of system errors are due to 'readback' discrepancies. A midair collision due to confusion over a clearance, regardless of who is the incorrect party, is unacceptable in light of the 'easy' remedy available. I have no doubt that the pilot not in command on light transport Y (or whomever was on the radio) was not the pilot that set in the altitude. He heard 'up 2-2-zero' being acknowledged and plugged it in.

Original NASA ASRS Text

Title: ARTCC RADAR CTLR CLBED AN LR31 TO FL200 ON A CONFLICTING COURSE WITH A C414 AT FL210. THE LR31 MISINTERP HIS ALT ASSIGNMENT AND CLBED THROUGH THE C414'S ALT WITH LTSS. RPTR FEELS THAT PHRASEOLOGY USED BY THE LR31 CONTRIBUTED TO THIS ERROR.

Narrative: SMT X WAS ENRTE THROUGH THE N DEP (#38) SECTOR AT HIS CRUISE ALT OF FL210. LTT Y WAS CLBING OUT OF AN ATLANTA SATELLITE ARPT, POSSIBLY FULTON COUNTY (FTY). THE CTLR ON THE SECTOR WAS EXTREMELY BUSY WITH A MIX OF OVERFLTS AND SATELLITE/ATL JET DEPS. TO FURTHER COMPLICATE THE SIT, THERE WAS CONVECTIVE WX ACTIVITY IN THE NORTHERN PORTION OF THE SECTOR NECESSITATING DEV FROM ASSIGNED ROUTING BY SEVERAL ACFT. ON INITIAL CONTACT, LTT Y WAS ISSUED A CLB CLRNC TO FL190 WHICH HE ACKNOWLEDGED BY READING BACK 'UP TO 1-9-0.' THE RTES OF FLT PUT LTT Y AND SMT X IN CONFLICTION NECESSITATING ALT SEPARATION. WHEN SUBSEQUENTLY CLBED TO FL200, LTT Y ACKNOWLEDGED WITH 'UP TO 2-ZERO.' LTT Y CLBED TO FL220 AND LOST SEPARATION WITH SMT X AT APPROX XA34 ON JUL/XA/97. WHEN QUESTIONED BY THE CTLR, LTT Y STATED THAT HE WAS ISSUED FL220 AND ACKNOWLEDGED THE ALT. CURIOUSLY, SMT X WAS ALSO ON THE FREQ AND ACKNOWLEDGED EACH OF HIS ALT CLRNCS WITH 'UP TO' THE ASSIGNED ALT. I BELIEVE BOTH OF THESE ACFT ARE FROM THE SAME COMPANY, POSSIBLY A COMPANY BASED IN INDIANAPOLIS. AFTER REVIEWING THE TAPES, THE CTLR WAS IDENTED AS PRIMARY IN THE ERROR FOR FAILURE TO INSURE A PROPER READBACK. FAR SHOULD BE AMENDED SO AS TO REQUIRE PLTS TO COMMUNICATE VIA STANDARD PHRASEOLOGY WHEN ACKNOWLEDGING CLRNCS/CTL COMS. NEITHER OF THESE ACFT WERE EQUIPPED WITH TCASII. A LARGE PERCENTAGE OF SYS ERRORS ARE DUE TO 'READBACK' DISCREPANCIES. A MIDAIR COLLISION DUE TO CONFUSION OVER A CLRNC, REGARDLESS OF WHO IS THE INCORRECT PARTY, IS UNACCEPTABLE IN LIGHT OF THE 'EASY' REMEDY AVAILABLE. I HAVE NO DOUBT THAT THE PLT NOT IN COMMAND ON LTT Y (OR WHOMEVER WAS ON THE RADIO) WAS NOT THE PLT THAT SET IN THE ALT. HE HEARD 'UP 2-2-ZERO' BEING ACKNOWLEDGED AND PLUGGED IT IN.

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.

ARTCC radar controller climbed an LR31 to FL200 on a conflicting course with a C414 at FL210. The LR31 misinterp his altitude assignment and climbed through the C414's altitude with less than standard separation. Reporter feels that phraseology used by the LR31 contributed to this error.