Near midair collision, both aircraft in contact with TRACON and radar identified.

Attributes
ACN	114091
Time
Date	198906
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lex
State Reference	KY
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lex
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	None
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 2 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 6 flight time total : 60
ASRS Report	114091
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	ATC Human Performance

Narrative:

Had been under control of lexington approach for 10 mins. They had us identify by transponder discrete code and mode C altitude reporting. 5 mins or so prior to the near miss lexington approach asked my aircraft to climb to 3000' which I did. My static system is current IFR certified. I was on a west heading tracking to the frankfort, ky VOR. From my right a twin engine aircraft passed overhead at less than 200' separation. I pushed my aircraft down. I informed the controller of the occurrence and he said aircraft passed well behind me. I replied he passed directly overhead. Our aircraft would not have collided, but were very close. He asked the twin to maintain 3000' after the incident. My concern is with transponder, altitude reporting, radar service and arsa's all in effect how come we came so close? Callback conversation with reporter revealed the following: when reporter made controller aware of other aircraft there was a long silence. Controller then said 'yes, I have another aircraft in vicinity', the comment about passing behind. No more was said to reporter but comment to twin to maintain altitude. Reporter concerned about altitude encoding accuracy and so confirmed with next controller when handed off. Reporter always aware of see and avoid and is constantly looking.

Original NASA ASRS Text

Title: NMAC, BOTH ACFT IN CONTACT WITH TRACON AND RADAR IDENTIFIED.

Narrative: HAD BEEN UNDER CTL OF LEXINGTON APCH FOR 10 MINS. THEY HAD US IDENT BY XPONDER DISCRETE CODE AND MODE C ALT REPORTING. 5 MINS OR SO PRIOR TO THE NEAR MISS LEXINGTON APCH ASKED MY ACFT TO CLIMB TO 3000' WHICH I DID. MY STATIC SYSTEM IS CURRENT IFR CERTIFIED. I WAS ON A W HDG TRACKING TO THE FRANKFORT, KY VOR. FROM MY RIGHT A TWIN ENGINE ACFT PASSED OVERHEAD AT LESS THAN 200' SEPARATION. I PUSHED MY ACFT DOWN. I INFORMED THE CTLR OF THE OCCURRENCE AND HE SAID ACFT PASSED WELL BEHIND ME. I REPLIED HE PASSED DIRECTLY OVERHEAD. OUR ACFT WOULD NOT HAVE COLLIDED, BUT WERE VERY CLOSE. HE ASKED THE TWIN TO MAINTAIN 3000' AFTER THE INCIDENT. MY CONCERN IS WITH XPONDER, ALT REPORTING, RADAR SERVICE AND ARSA'S ALL IN EFFECT HOW COME WE CAME SO CLOSE? CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: WHEN REPORTER MADE CTLR AWARE OF OTHER ACFT THERE WAS A LONG SILENCE. CTLR THEN SAID 'YES, I HAVE ANOTHER ACFT IN VICINITY', THE COMMENT ABOUT PASSING BEHIND. NO MORE WAS SAID TO REPORTER BUT COMMENT TO TWIN TO MAINTAIN ALT. REPORTER CONCERNED ABOUT ALT ENCODING ACCURACY AND SO CONFIRMED WITH NEXT CTLR WHEN HANDED OFF. REPORTER ALWAYS AWARE OF SEE AND AVOID AND IS CONSTANTLY LOOKING.

Data retrieved from NASA's ASRS site as of August 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.