Date: 201507
Local time of day: 0601-1200
Location: MD50.Airport, MD
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Final Approach; Taxi; Initial Approach; Landing
Airspace: Class D NHK; Class E ZDC; Class G MD50
ATC / advisory: Tower NHK; UNICOM MD50
Second aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Human factors: Communication Breakdown; Confusion; Time Pressure; Situational Awareness
Anomaly: Conflict Airborne Conflict; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Flight Crew
When detected: In-flight; Taxi
Result: Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: Returning to MD50; I contacted NHK crossing GOFER for entry into their Class D/transition to MD50; and was approved. Prior to this point; I had been listening to NHK Tower (123.7) and MD50 UNICOM and had heard one aircraft approved for transition into MD50 minutes prior to our arrival at GOFER. We then asked for change in frequency to MD50 UNICOM (122.7) as I was aware there were other aircraft in the area also returning to MD50 and was approved also. All subsequent communication from my aircraft were conducted on 122.7. Crossing Cove point (approximately 2NM NE) and having heard no other communications I announced our position and altitude (1000 MSL) and intention to make a crosswind entry for Runway 31. At this point; I noticed another aircraft; approximately 3 o'clock to our position and hundreds of feet above us; approximately one mile away and headed for MD50 approximately midfield. That aircraft crossed midfield ahead of me still above my altitude (still 1000 MSL) and descending; now approximately one quarter mile ahead; and announced that he would circle the field. At this point the pilot began a gentle right turn. I began a left turn to de-conflict while maintaining visual contact with the aircraft when it abruptly reversed its turn and began a much quicker left turn towards us. I reversed my turn to pass behind and below; and announced we had them in sight and would avoid them while they figured out what they were going to do. I continued NW and the other pilot acknowledged our transmission and its intention to enter downwind for Runway 31; which it was doing. Once we had more than one half mile separation; and visually verifying there was no other traffic in the area; I turned back to join the downwind still at 1000 MSL and announced we were number two behind the other aircraft; with no acknowledgement.I observed the aircraft continue its pattern; and proceed to land on the grass area NE of the MD50 runway; and I announced base and then final with no acknowledgement from the other pilot. As I crossed the threshold the other aircraft was stationary; still on the grass alongside the runway and facing away from us. As I touched down on the runway; the other pilot announced it was back-taxiing on Runway 31 and turned onto the runway. I was shocked; began aggressive braking; and announced 'get off the runway' on UNICOM. I was looking for a way around the edge lighting into the grass; when the other aircraft rapidly egressed to the opposite (SW) side. I then completed the rollout on the runway surface.We had already touched down on the paved runway surface and had begun rollout when the other aircraft entered the runway; in my opinion without even looking (they could not have as there would have been no visibility down the runway until it had turned and was in the process of crossing onto the runway). I would say the closest approach was approximately 500 feet. MD50 is a relatively short field. It is my belief that if I had landed longer or faster; there would likely have been a collision between the aircraft.




Synopsis: A general aviation pilot who approached and landed at MD50 reported inconsistent pilotage by another pilot prior to landing and a runway incursion by that same pilot as the reporter rolled out after landing.