PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Commercial; Flight Crew Flight Instructor
Distraction; Situational Awareness; Workload
Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Airspace Structure; Environment - Non Weather Related
On a routine instrument approach training flight we planned to depart on a practice Deer Valley 1 Departure from Runway 25L. The departure just previous to us was also for the Deer Valley 1 Departure; they were another training flight; also VFR practice on the procedure. After they were cleared for takeoff; we held short and waited for one arrival to land full stop on [Runway] 25L; then received our clearance. In my estimation; perhaps 3 minutes passed between departures. We departed [Runway] 25L and received clearance for the right turn at 400 FT AGL with a frequency change to North Tower. On the HDG 060 leg of the procedure we were cleared for frequency change from North Tower; and switched to receive FFZ ATIS. Upon intercepting the PHX R-336 and proceeding outbound in the climb we encountered and increased climb rate due to local lifting action: over 1;000 FPM sustained. Initially my student did not recognize the increased climb rate and we reached 4;200 FT before he initiated the left turn on the procedure; while simultaneously switching frequencies to PHX Approach Control to make our VFR request for practice FFZ GPS B. As we initiated the turn I picked up the traffic visually at our altitude 11 o'clock and southbound. I took flight controls from the student and initiated a right hand turn; and the other aircraft also took evasive action; turning to their right before proceeding on course. The other aircraft was headed direct AVENT to initiate the FFZ GPS B approach. The main factors that lead to the NMAC were the identical flight profiles of the two missions; the perceived separation provided by difference in departure time; the design of the Deer Valley 1 Departure and the location of the IAF AVENT on the practice approach; and the increased cockpit workload during this operation. The identical flight profile guaranteed that nearly the same space would be occupied by each aircraft; with time being the only separating factor. The perceived separation provided by the difference in departure time was a significant factor. Due to the fact that both aircraft were of identical type; and similarly loaded; their performance should have been similar enough to provide separation. It was only due to the local atmospheric conditions encountered by our aircraft; that were not encountered by the previous flight; that a conflict occurred. When separation is closer DVT Tower will generally not issue a frequency change without a confirmation of traffic in sight. In our case the traffic was outside of the northern edge of DVT airspace when our frequency change was approved. The design of the Deer Valley 1 Departure and location of the IAF AVENT mean that an aircraft will make a 180 degree left hand turn on the departure and then turn further to the left to proceed direct AVENT (which is on the PHX R-336); meaning that the aircraft that proceeded us was returning to the same radial inbound that we were leaving outbound. [This] put us both just to the west of the PHX R-336. All of the previous factors explain how the two aircraft ended up in the same place at the same time. All of which is alright given our responsibility to see and avoid other traffic. The largest factor that led to a NMAC was the distraction of the increased workload in each cockpit during this phase of flight. The flight profile on this mission has you flying a practice departure procedure; receive a frequency change; collect ATIS; change frequency to request the practice approach; reconfigure the avionics for the approach; and complete the appropriate checklists before reaching the IAF. All of those actions take place in less than 5-7 minutes; which makes it so desirable to fly as a training exercise. However; the workload is not only high for the student; and the instructor; in addition to his other duties; is the sole party responsible for see and avoid collision avoidance during the flight. As I took evasive action the other flight was in mid-transmissionrequesting their practice approach when they cut their transmission short and took evasive action; leading me to believe that the instructor aboard that aircraft picked us up visually and took control from his student at nearly the same time I did.See and avoid needs to take precedence over other cockpit activity even during high workloads. Both aircraft were out of contact with ATC during the time leading to NMAC; having received the frequency change from DVT and not yet having contacted PHX Approach. Radar service could have helped early recognition. The use of TIS and TCAS in the terminal environment often seems like more of a distraction than a tool due to the high number of close targets. However; I feel that proper use of these tools could have helped with early detection in this case.
A PA-28 Instructor reported taking evasive action from another PA-28 near AVENT intersection while both aircraft were conducting training and initiating the FFZ GPS B approach.