Okc controller transposes military training call signs issuing incorrect clrncs, resulting in a loss...

Attributes
ACN	439076
Time
Date	199905
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : okc.ils
State Reference	OK
Altitude	msl bound lower : 3000 msl bound upper : 4500
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Beechjet 400
Operating Under FAR Part	Part 91
Navigation In Use	ils localizer & glide slope : 17r other
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	approach : instrument precision arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : okc.tracon
Operator	other
Make Model Name	Beechjet 400
Navigation In Use	other
Flight Phase	descent : intermediate altitude descent : approach
Route In Use	approach : visual arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : military
Function	flight crew : captain oversight : pic
Qualification	pilot : military pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 178 flight time total : 2000 flight time type : 360
ASRS Report	439076
Person 2
Affiliation	government : military
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Military training flight, a formation of 2 BE40's, call sign 'MTR2X flight,' needed to split up and get separate IFR clrncs to penetrate the WX and land at okc. From 10000 ft MSL and in VMC, each aircraft was given a separate squawk and a vector to sequence us in to the active runway 17R. Confusion by the controller (I believe) about who was where in the formation, brought us to an near midair collision. When the separate clrncs were issued and squawks set, MTR2X was lead aircraft and MTR1 was the wingman. MTR2X took vectors to the ILS runway 17R, while MTR1Y took vectors for a visual to runway 17R. A late turn to final and cleared 3000 ft MSL, MTR2X broke out of the WX in a descent through 4500 ft MSL. I (MTR1Y) reacted to a TCASII warning and leveled off. While I continued to intercept final (sbound), a twin propeller aircraft passed underneath me (eastbound) by 200 ft (per TCASII). I estimate the twin was at 4000 ft MSL. No call for traffic or avoidance vectors were ever given by okc approach. When approach switched my wingman (4 mi or so in trail of me) to tower before they switched me (I asked to be switched inside the FAF on approach), I realized there must have been a call sign mix-up about who was in front. The supervisor for okc approach was notified by phone on the ground of the incident.

Original NASA ASRS Text

Title: OKC CTLR TRANSPOSES MIL TRAINING CALL SIGNS ISSUING INCORRECT CLRNCS, RESULTING IN A LOSS OF SEPARATION.

Narrative: MIL TRAINING FLT, A FORMATION OF 2 BE40'S, CALL SIGN 'MTR2X FLT,' NEEDED TO SPLIT UP AND GET SEPARATE IFR CLRNCS TO PENETRATE THE WX AND LAND AT OKC. FROM 10000 FT MSL AND IN VMC, EACH ACFT WAS GIVEN A SEPARATE SQUAWK AND A VECTOR TO SEQUENCE US IN TO THE ACTIVE RWY 17R. CONFUSION BY THE CTLR (I BELIEVE) ABOUT WHO WAS WHERE IN THE FORMATION, BROUGHT US TO AN NMAC. WHEN THE SEPARATE CLRNCS WERE ISSUED AND SQUAWKS SET, MTR2X WAS LEAD ACFT AND MTR1 WAS THE WINGMAN. MTR2X TOOK VECTORS TO THE ILS RWY 17R, WHILE MTR1Y TOOK VECTORS FOR A VISUAL TO RWY 17R. A LATE TURN TO FINAL AND CLRED 3000 FT MSL, MTR2X BROKE OUT OF THE WX IN A DSCNT THROUGH 4500 FT MSL. I (MTR1Y) REACTED TO A TCASII WARNING AND LEVELED OFF. WHILE I CONTINUED TO INTERCEPT FINAL (SBOUND), A TWIN PROP ACFT PASSED UNDERNEATH ME (EBOUND) BY 200 FT (PER TCASII). I ESTIMATE THE TWIN WAS AT 4000 FT MSL. NO CALL FOR TFC OR AVOIDANCE VECTORS WERE EVER GIVEN BY OKC APCH. WHEN APCH SWITCHED MY WINGMAN (4 MI OR SO IN TRAIL OF ME) TO TWR BEFORE THEY SWITCHED ME (I ASKED TO BE SWITCHED INSIDE THE FAF ON APCH), I REALIZED THERE MUST HAVE BEEN A CALL SIGN MIX-UP ABOUT WHO WAS IN FRONT. THE SUPVR FOR OKC APCH WAS NOTIFIED BY PHONE ON THE GND OF THE INCIDENT.

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.

Okc controller transposes military training call signs issuing incorrect clrncs, resulting in a loss of separation.