Date: 201509
Local time of day: 0601-1200
Location: D01.TRACON, CO
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Initial Approach
Airspace: Class E D01
ATC / advisory: TRACON D01
Second aircraft: Amateur/Home Built/Experimental
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Situational Awareness
Anomaly: Conflict NMAC; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was flying with a good friend who owns our aircraft and is also a CFI. He was in the copilot's seat at the time of the incident. I was controlling the aircraft. We fly periodically for IFR practice; which was the mission for this flight. We were headed to [a nearby airport] for some ILS practice approaches to their runway. After transitioning from APA Tower to Denver Approach Control; the Controller vectored us north; so I came to a heading of 360. The Controller called to advise us of an overtaking aircraft off our right side; and I responded; 'Looking for traffic.' Suddenly; and very unexpectedly; we saw an aircraft speed by us on the right side. I didn't see the aircraft until it was more in front of us at the 1-2 o'clock position. We were both very startled at how close the aircraft had passed by us; and then we felt the wake turbulence from this other aircraft. It was moving much faster than we were and quickly disappeared off in the distance. I immediately called Denver Approach and told the Controller that the overtaking aircraft had passed by very close to us; and said somewhat in jest that my heart rate was coming back down! The Denver Approach Controller said; 'Sorry about that; he's not talking to anybody. Do you consider it to be a near-miss?' I turned to my copilot; and we both agreed that it was. I reported; 'yes'; to the Controller. The Controller said they would talk to the pilot as soon as he landed at [same destination]. We decided to continue the flight and did the practice ILS approaches. During one practice approach; the Denver Approach Controller said that they talked with the other pilot; who was flying an experimental aircraft; and he didn't think it was any big deal because he had us on his TCAS. The Controller went on to say that they were going to write him up and that we would be asked to submit a report. Subsequently; we were asked for such a report and filed it with the local FAA Flight Standards District Office. I am submitting this report so that you have the information on what happened with this specific incident. What can be done to prevent it in the future is; in my opinion; primarily training. The other pilot needs education on flying a high performance aircraft and the importance of giving other aircraft a wide berth.




Synopsis: C172 reported an NMAC when they were passed by a faster aircraft departing APA.