Close proximity air carrier-medium large transport GA-small aircraft on airway just above den TCA.

Attributes
ACN	166790
Time
Date	199012
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : den
State Reference	CO
Altitude	msl bound lower : 14500 msl bound upper : 14800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den artcc : zma
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : on vectors enroute airway : den
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 8500 flight time type : 1800
ASRS Report	166790
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 200 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

On descent into denver stapleton airport descending from 17000' to 12000'. We had just been given a turn to 070 degrees heading and a speed adjustment to 170 KTS. Passing through 14800' or so we observed an aircraft at out 12 O'clock closing at approximately 3/4 to 1/2 mi. We began an evasive turn to the right and the other aircraft was then observed to begin an evasive turn to his right. He passed down the left side of my aircraft at what I estimate to be 200' lateral. It was a low wing blue and white single engine aircraft. We did not receive a radio transmission from ATC until we had already begun our evasive turn. If small aircraft are going to insist on flying in the vicinity of major hub airports they should be required to be under radar control. This aircraft was above the TCA VFR.

Original NASA ASRS Text

Title: CLOSE PROX ACR-MLG GA-SMA ON AIRWAY JUST ABOVE DEN TCA.

Narrative: ON DSNT INTO DENVER STAPLETON ARPT DSNDING FROM 17000' TO 12000'. WE HAD JUST BEEN GIVEN A TURN TO 070 DEGS HDG AND A SPD ADJUSTMENT TO 170 KTS. PASSING THROUGH 14800' OR SO WE OBSERVED AN ACFT AT OUT 12 O'CLOCK CLOSING AT APPROX 3/4 TO 1/2 MI. WE BEGAN AN EVASIVE TURN TO THE R AND THE OTHER ACFT WAS THEN OBSERVED TO BEGIN AN EVASIVE TURN TO HIS R. HE PASSED DOWN THE L SIDE OF MY ACFT AT WHAT I ESTIMATE TO BE 200' LATERAL. IT WAS A LOW WING BLUE AND WHITE SINGLE ENG ACFT. WE DID NOT RECEIVE A RADIO XMISSION FROM ATC UNTIL WE HAD ALREADY BEGUN OUR EVASIVE TURN. IF SMALL ACFT ARE GOING TO INSIST ON FLYING IN THE VICINITY OF MAJOR HUB ARPTS THEY SHOULD BE REQUIRED TO BE UNDER RADAR CTL. THIS ACFT WAS ABOVE THE TCA VFR.

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.