Date: 201209
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: FBO
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Second aircraft: Cirrus Aircraft Undifferentiated
Reporter organization: FBO
Reporter function: Instructor; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor
Second reporter function: Pilot Flying; Trainee
Anomaly: Conflict NMAC
Detector: Automation Aircraft TA; Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Airspace Structure; Human Factors
Primary problem: Human Factors

Narrative: My instrument student and I were flying a practice ILS approach. We were inside Class B and were being vectored by Approach at an altitude of 2;500 FT MSL. We were assigned a vector for the approach with the autopilot on. The Air Traffic Controller told us to descend to 2;000 FT and then asked us to expedite for traffic. My student pressed vertical speed and the nose down button on the autopilot to start a descent. I told my student to disengage the autopilot and descend manually. I was looking outside for traffic and did not notice our rate of descent had decreased. The Controller asked us again to expedite our descent and told us traffic was at our 12 o'clock heading directly toward us. I told my student to bring the power to idle and push the nose down during the time she was reading back the traffic call. The instructions from the Controller and the read-back from the student took approximately 7-10 seconds. During this time a traffic alert was issued on our Traffic Information System (TIS) display on the Garmin 1000 Multifunction Display (MFD). I spotted the traffic as they were slightly ahead of us and about 200-300 FT above our position. They did not have any taxi lights or landing lights turned on. The Controller told us traffic was climbing to 3;000 FT and was no longer a factor. We were cleared for the ILS approach and handed off to Tower. The Controller's instructions were a little long and my student tried to read back all instructions. I believe in this case the Controller's instructions were a little too long and the read-back from my student distracted her from flying the airplane. I also should have immediately taken the controls to start the descent. The other aircraft should have turned on their landing and taxi lights in the terminal environment regardless of day or night. We had ours on.


Second narrative: My instrument instructor and I were being vectored by Approach Control for a practice ILS or LOC approach. We were cleared into Class B airspace at 2;500 MSL. I was 'under the hood' for simulated instrument conditions while my instructor was observing traffic. Approach told us expedite a 200 FT descent for traffic which wasn't in contact with the Controller. I pressed the vertical speed button down on the autopilot to begin descent. My instructor told me to disengage the autopilot and descend manually. At this time; the Controller called us again to expedite our descent and described the aircraft as Cirrus traffic which was at our 12 o-clock climbing straight towards us. I read back our instructions and manually descended. My instructor saw the traffic as they were in front and on top of us by about 300 FT and noted they didn't have their taxi or landing lights on. The Controller advised that traffic was no longer a factor and we were transitioned to Tower frequency to continue the approach and landed with no incident.I should have disengaged the autopilot immediately when I heard the Controller give us the first call to expedite descent and been more focused on flying than reading back our instructions. Also; the Cirrus aircraft should have had their taxi and landing lights on so traffic could identify them easier. They also should have been communicating with the Approach Controller sooner for instructions and traffic separation.


Synopsis: C172 Student and Instructor experience a NMAC with a Cirrus in Class B airspace while being vectored for an ILS approach for a satellite airport. The Cirrus pilot was not talking to Approach Control.