B737-5 flight crew encounters a vehicle entering the runway during landing roll at den.

Attributes
ACN	725836
Time
Date	200702
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : den.airport
State Reference	CO
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	tower : den.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	landing : roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	oversight : pic
Experience	flight time last 90 days : 160 flight time total : 13000 flight time type : 3000
ASRS Report	725836
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 240 flight time total : 5000 flight time type : 800
ASRS Report	725833
Events
Anomaly	conflict : ground critical ground encounters : vehicle incursion : runway non adherence : published procedure non adherence : far
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 200
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Airport
Primary Problem	Airport
Air Traffic Incident	Inter Facility Coordination Failure

Narrative:

On short final; after being cleared to land; the first officer and I observed a snowplow slowly moving towards our landing runway from an unnamed service road from left to right. Although not verbalized; we both wondered if it was going to hold short; and I mentally prepared to go around. The plow proceeded to stop just short of the runway; so we both concluded that he had seen us and would continue to hold short. On rollout at somewhere between 60-100 KTS I observed the plow slowly entering the runway environment. I immediately took the controls from the first officer and applied significant reverse thrust and manual braking to avoid contact with the plow. At about that time it looked as if the driver had seen us and was accelerating to clear the runway. I would guesstimate we stopped the aircraft somewhere within 100-300 ft of the spot where the plow was quickly exiting the runway. Once stopped; we reported the incident to tower before exiting the runway at the 1ST high-speed. We then taxied to the gate without incident. About halfway to the gate the tower supervisor came on the frequency and asked what had happened and if we had almost hit an animal on the runway.

Original NASA ASRS Text

Title: B737-5 FLT CREW ENCOUNTERS A VEHICLE ENTERING THE RWY DURING LNDG ROLL AT DEN.

Narrative: ON SHORT FINAL; AFTER BEING CLRED TO LAND; THE FO AND I OBSERVED A SNOWPLOW SLOWLY MOVING TOWARDS OUR LNDG RWY FROM AN UNNAMED SVC ROAD FROM L TO R. ALTHOUGH NOT VERBALIZED; WE BOTH WONDERED IF IT WAS GOING TO HOLD SHORT; AND I MENTALLY PREPARED TO GO AROUND. THE PLOW PROCEEDED TO STOP JUST SHORT OF THE RWY; SO WE BOTH CONCLUDED THAT HE HAD SEEN US AND WOULD CONTINUE TO HOLD SHORT. ON ROLLOUT AT SOMEWHERE BTWN 60-100 KTS I OBSERVED THE PLOW SLOWLY ENTERING THE RWY ENVIRONMENT. I IMMEDIATELY TOOK THE CTLS FROM THE FO AND APPLIED SIGNIFICANT REVERSE THRUST AND MANUAL BRAKING TO AVOID CONTACT WITH THE PLOW. AT ABOUT THAT TIME IT LOOKED AS IF THE DRIVER HAD SEEN US AND WAS ACCELERATING TO CLR THE RWY. I WOULD GUESSTIMATE WE STOPPED THE ACFT SOMEWHERE WITHIN 100-300 FT OF THE SPOT WHERE THE PLOW WAS QUICKLY EXITING THE RWY. ONCE STOPPED; WE RPTED THE INCIDENT TO TWR BEFORE EXITING THE RWY AT THE 1ST HIGH-SPEED. WE THEN TAXIED TO THE GATE WITHOUT INCIDENT. ABOUT HALFWAY TO THE GATE THE TWR SUPVR CAME ON THE FREQ AND ASKED WHAT HAD HAPPENED AND IF WE HAD ALMOST HIT AN ANIMAL ON THE RWY.

Data retrieved from NASA's ASRS site as of January 2009 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.