Date: 201701
Local time of day: 1801-2400
Location: FDK.Airport, MD
Flight conditions: VMC
Weather elements / visibility: 10
Light: Night
Aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Operating under: Part 91
Flight plan: VFR
Flight phase: Landing
Airspace: Class D FDK
ATC / advisory: Tower FDK
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Human factors: Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Conflict NMAC; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Human Factors
Primary problem: Ambiguous

Narrative: I was in the pattern at FDK this evening. On my first pattern go around I requested closed pattern with the option. I was cleared to take off on 23; but I do not remember getting any command to make left or right traffic. As I climbed out; I queried the tower for instruction. I recall getting left traffic and cleared to land all at the same time. I think I clarified this with the tower and replied that I would call mid-field left downwind for 23. The tower apologized for the confusing and perhaps non-standard command. The tower then acknowledged my read back - even though it was not the command he gave. Once I hit mid-field left downwind for 23; I called and was cleared to land.On my final departure I was cleared to take off on Runway 23 with left turn approved. That was the entire command and I acknowledged. I climbed out to 1000 and on my left turn I immediately hear an aircraft asking the tower 'was that a plane that just flew over the top of us?' I looked down to my 9 o'clock and saw the aircraft below me. Perhaps at 600 feet; only 400 ft directly below me.I responded I had the traffic. The tower wanted to know if I had 'turned left early'. At first I said that I did; so the tower told me that I was not approved for an early turn. I then realized that I definitely had not turned early; as I was already at 1000 feet and I had used I-70 as the landmark to make the turn; and I saw the runway behind me. It was dark and you could not see the rock quarry; and you also do not want to blunder ahead on course 230 and penetrate the SFRA - hence I go over I-70 and then turn. The tower told me 'be careful next time'.I did not hear the initial radio calls of the aircraft that almost hit me. I was only tracking the other 2 aircraft that were approved for the ILS 23 approach. My situational awareness was concentrating on the aircraft behind me; and not the aircraft in front of me. Lesson learned for sure.But - why did the tower allow an aircraft to enter crosswind directly in front of a departing aircraft? The tower cleared me to take off and then put me in direct conflict with an approaching aircraft from my right that was entering left crosswind for 23. If the conflict aircraft was at pattern altitude - we would have collided; fatally.




Synopsis: General Aviation pilot reported an NMAC in the pattern at FDK airport.