Small aircraft on pipeline patrol has near midair collision with aircraft opposite direction.

Attributes
ACN	193651
Time
Date	199111
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den
State Reference	CO
Altitude	agl bound lower : 500 agl bound upper : 500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : cfi
Experience	flight time total : 3500 flight time type : 2300
ASRS Report	193651
Person 2
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other other : unspecified cockpit
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 50 vertical : 150
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

I was proceeding northbound on our pipeline observing the line. I looked up to clear the airspace around me when I saw a high wing small aircraft fly over the top of my aircraft. The other aircraft was proceeding in a southerly direction.

Original NASA ASRS Text

Title: SMA ON PIPELINE PATROL HAS NMAC WITH ACFT OPPOSITE DIRECTION.

Narrative: I WAS PROCEEDING NBOUND ON OUR PIPELINE OBSERVING THE LINE. I LOOKED UP TO CLR THE AIRSPACE AROUND ME WHEN I SAW A HIGH WING SMA FLY OVER THE TOP OF MY ACFT. THE OTHER ACFT WAS PROCEEDING IN A SOUTHERLY DIRECTION.

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.