Date: 201706
Local time of day: 0001-0600
Location: PRC.Tower, AZ
Aircraft: Skyhawk 172/Cutlass 172
Operator: FBO
Operating under: Part 91
Flight plan: IFR
Mission: Training
Flight phase: Taxi
ATC / advisory: Tower PRC
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Troubleshooting
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance
Contributing factors: Procedure; Company Policy; Airspace Structure
Primary problem: Company Policy

Narrative: Tower and TRACON started a new LOA (Letter of Agreement). The new LOA states that all south westbound departures shall be issued a DVA (diverse vectoring Area) heading of 200. The MVA (Minimum Vectoring Altitude) in this area is 9;000 feet. [An on field flight school] has stated that their C172's are not capable of meeting the required climb rate to meet our departure procedure which requires them to fly heading 200 until reaching 7;300 feet. They have also stated that their C172's are not capable of meeting the climb rate for the DVA heading of 200 until reaching 9;000 feet; the point at which TRACON can issue them a new heading. The new DVA procedure is worse than the previous ODP (Obstacle Departure Procedure) in that they have to climb another 1;700 feet into rising terrain before being able to turn.As Aircraft X was taxiing out I called TRACON and requested approval for on course to DRK instead of the DVA heading of 200. The controller approved it and I issued the clearance via DRK as filed. A few minutes later the aircraft called ready for departure the same time as TRACON called back and said that the aircraft had to depart via the DVA and could not go via DRK. I told the controller that the aircraft could not comply with the DVA or ODP because of aircraft performance and required their own navigation on course. The controller said unable and that he wasn't trying to be difficult; he was just doing what those above him told him to do.I called the Supervisor desk at the TRACON. The Supervisor kept repeating 'you don't understand' and explained that they would have to clear out their entire airspace in order to depart this aircraft and that they would have to wait for other IFR aircraft in the area to vacate or go VFR. I told him that there were no other IFR aircraft and why had this changed from 4 days earlier; prior to the new LOA? They've been doing this exact procedure for more than 3 years and all of the sudden it's no longer available? He wanted to keep debating the issue but I told him the aircraft had been waiting for a release and we wanted to get them airborne. I called TRACON back and again asked for a release. The controller was explicit that we give no course guidance which is what we've been doing for forever and for the last 3 years with TRACON; and finally issued a release. The DVA is for the sole benefit of the approach controller and typically a huge disservice for the pilot. The C525 that departed prior didn't hit 9;000 until nearly 7 miles from the airport. The PC12 that departed after them didn't hit it until 9 miles from the airport. With the temp at 32C and density altitude at 8;000+; a Cessna wouldn't stand a chance of legally clearing the mountains south of the airport on a DVA heading. Either educate the TRACON that anything can be accomplished with coordination and that aircraft can be allowed to go direct to their first fix with prior coordination; just as they have done so for years; or do away with the DVA in the new LOA.




Synopsis: A Tower Controller reported on the difficulties with single engine piston aircraft complying with a new departure procedure.