Close proximity 2 GA-small aircraft aircraft at base of den TCA.

Attributes
ACN	101252
Time
Date	198812
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : apa
State Reference	CO
Altitude	msl bound lower : 7800 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den tower : dca
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Route In Use	enroute : on vectors enroute : direct
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 57 flight time total : 227 flight time type : 119
ASRS Report	101252
Person 2
Function	observation : passenger
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 120
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

We reported leaving buckley ANG on a missed ILS approach (practice only, no hood, excellent VFR) and were told 120 degrees 7500' by den 119.3. 14 NM southeast of buckley ATC instructs '8700, 240 degrees, direct casse upon receiving casse.' casse was identing clearly and indicator homing so we tracked toward casse 240 degrees (estimated 17 mi from casse). At about 13 mi from casse ATC instructed 'climb 8700.' at 8 mi from casse, 7800' (?), my rider squirms (he's been listening to 119.3 all along too), 'I think there is an aircraft southbound coming our way.' seconds later I saw a low wing aircraft at 1:30 in the very top of the windshield. I could see all of him. We dove 200' and I screwed up the pattern entry at centennial airport. I wish ATC could have more people and better equipment/procedures to track VFR. We were in radar contact, squawking assigned code. We had a hunch that the other aircraft was squawking 1200. I understand that our triangular radar 'tag' may have obliterated his 1200 return, and it was very busy that day at centennial and den, both. I went back up for some dual IFR training and I noticed den doing the greatest job of separating VFR/IFR VFR/VFR traffic I have ever heard. May we all learn something that day.

Original NASA ASRS Text

Title: CLOSE PROX 2 GA-SMA ACFT AT BASE OF DEN TCA.

Narrative: WE RPTED LEAVING BUCKLEY ANG ON A MISSED ILS APCH (PRACTICE ONLY, NO HOOD, EXCELLENT VFR) AND WERE TOLD 120 DEGS 7500' BY DEN 119.3. 14 NM SE OF BUCKLEY ATC INSTRUCTS '8700, 240 DEGS, DIRECT CASSE UPON RECEIVING CASSE.' CASSE WAS IDENTING CLEARLY AND INDICATOR HOMING SO WE TRACKED TOWARD CASSE 240 DEGS (ESTIMATED 17 MI FROM CASSE). AT ABOUT 13 MI FROM CASSE ATC INSTRUCTED 'CLB 8700.' AT 8 MI FROM CASSE, 7800' (?), MY RIDER SQUIRMS (HE'S BEEN LISTENING TO 119.3 ALL ALONG TOO), 'I THINK THERE IS AN ACFT SBND COMING OUR WAY.' SECS LATER I SAW A LOW WING ACFT AT 1:30 IN THE VERY TOP OF THE WINDSHIELD. I COULD SEE ALL OF HIM. WE DOVE 200' AND I SCREWED UP THE PATTERN ENTRY AT CENTENNIAL ARPT. I WISH ATC COULD HAVE MORE PEOPLE AND BETTER EQUIP/PROCS TO TRACK VFR. WE WERE IN RADAR CONTACT, SQUAWKING ASSIGNED CODE. WE HAD A HUNCH THAT THE OTHER ACFT WAS SQUAWKING 1200. I UNDERSTAND THAT OUR TRIANGULAR RADAR 'TAG' MAY HAVE OBLITERATED HIS 1200 RETURN, AND IT WAS VERY BUSY THAT DAY AT CENTENNIAL AND DEN, BOTH. I WENT BACK UP FOR SOME DUAL IFR TRNING AND I NOTICED DEN DOING THE GREATEST JOB OF SEPARATING VFR/IFR VFR/VFR TFC I HAVE EVER HEARD. MAY WE ALL LEARN SOMETHING THAT DAY.

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.