Date: 201810
Local time of day: 0601-1200
Location: D50.Airport, ND
Flight conditions: VMC
Weather elements / visibility: 10
Aircraft: Small Transport; Low Wing; 2 Recip Eng
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Passenger
Flight phase: Landing
Airspace: Class G D50
ATC / advisory: CTAF D50
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Private; Flight Crew Multiengine
Human factors: Situational Awareness; Communication Breakdown
Anomaly: Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Person / Animal / Bird
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure; Airport
Primary problem: Ambiguous

Narrative: Received a weather briefing describing clear VFR conditions to D50. Proceeded to fly without event to D50. Called in on UNICOM at 25 miles out; 15 miles out; and 5 miles out with no response. Descended; turned base to final fairly close to the runway threshold. The surrounding terrain was yellow stubble. Just before touchdown I saw a very faded yellow 'X' in the yellow stubble ground area off the approach end of the runway. I immediately looked down the runway. The only movement I saw was on the left side at the beginning of the runway - I spotted a workman in a dingy high-visibility work jacket. I saw no other obstacles. Being very low and slow I made the decision to complete my landing. As soon as the airplane touched down approximately 1;000 feet down the runway 2 additional workmen walked out of the yellow stubble directly onto the runway - one from each side. I applied the brakes. When it became apparent the workers did not see me or hear me I locked the brakes. One of the skid marks was approximately 800 feet long. While the plane was skidding I maneuvered to the far right side of the runway. At the last minute the workmen finally saw me and/or heard me and stepped aside. I continued to taxi onto the ramp and park the airplane.I parked the plane on the ramp. I went to speak to members of the work party who were cleaning cracks in preparation for putting asphalt in the cracks on the runway. All of their equipment and pickups were on the ramp. I didn't see any of this during my approach. I was very surprised but none of them seemed affected or alarmed by the near miss. I inquired whether they had any radios or communication devices. They assured me they did not. I then called the airport manager who was not in the area at the time. During this phone call the airport manager told me they had just decided to do the work and had started [earlier] that morning. Between the airport manager; myself; and the leader of the men working on the runway; we decided that when they paused for lunch I would take off to fly back [home]. The right main tire was worn from the skidding and I had the tire changed that afternoon.My local FBO informed me that the notice for the airport closure went out approximately 10 minutes I received my flight briefing. No equipment or people were hurt. The faded yellow 'X' and the dingy yellow jackets made it impossible for me to see when they were in the yellow stubble. Had the 'X' been on the runway instead of in the stubble I would have likely seen it and flown around.The workmen were wearing earmuffs or ear protection which apparently prevented them from hearing the noise from the airplane as I was landing.They apparently did not see me landing either because they walked from the yellow stubble directly onto the runway in front of me after I had already touched down.I have approached airports in the past that I was unaware were closed and the bright ORANGE 'X' on the end of those runways was very easy to spot from a distance and thus allowed me to avoid attempting to land on such closed runways at those airports.




Synopsis: GA pilot reported unknowingly landing on a closed runway and braking hard to avoid personnel on runway.