Date: 201605
Local time of day: 0601-1200
Location: DVT.Airport, AZ
Flight conditions: VMC
Light: Daylight
Aircraft: Small Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Final Approach
Airspace: Class D DVT
ATC / advisory: TRACON P50; Tower DVT
Reporter organization: Personal
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor
Human factors: Communication Breakdown; Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Procedure; Human Factors
Primary problem: Procedure

Narrative: We departed [departure airport] and climbed on a 360 heading to 4;500 feet. Contacted Phoenix Approach on 120.7 and requested a practice RNAV-B into Deer Valley Airport (DVT). Given a discrete squawk code by ATC with radar contact; and told to maintain VFR with own navigation and advise when established on the approach. Became established on the RNAV-B at 4;600 feet and 3 miles from initial fix KNOBB. After advising Phoenix Approach; we were cleared for a VFR practice approach of the RNAV-B into Deer Valley and to maintain VFR. We proceeded inbound from KNOBB on a heading of 254 and began descending from 4;600 to 3;100 until passing final approach fix JERGI. Two miles from JERGI I requested a frequency change from Phoenix Approach and switched to Deer Valley Tower 120.2 and advised inbound 25L on the RNAV-B. I was told to contact the other tower frequency 118.4 and was cleared for the option 25L. After going around on 25L I was given the Deer Valley phone number and told to call for a possible pilot deviation.After calling; I was told was that I had entered the Class D airspace without first contacting Deer Valley tower and the incident would be investigated. What I believe led to the incident was the wrong assumption that because I was communicating with Phoenix Approach and on a discrete squawk code I was cleared into Deer Valley's class D; or I would be told to contact tower prior to entering their airspace. I thought it odd that we were so close to the FAF without being told to contact Deer Valley Tower; which is why I requested a frequency change from ATC. The lack of a handoff from Phoenix Approach to Deer Valley Tower in a timely manner led to the possible deviation. Normally; Approach would be in contact with Tower and seamlessly hand off the aircraft so that they may be told to continue on the approach and be cleared to land. This is the way it worked for the three other approaches we shot on that flight.The situation could be prevented in the future by making it more clear that aircraft on VFR practice approaches are not only responsible for keeping separation from other aircraft; but are also responsible for gaining clearance into any airspace they may enter while on the approach. A lesson that I have learned the hard way; but will certainly be more vigilant about for the rest of my career.




Synopsis: Pilot reported doing a practice approach into an airport with approach control and then was advised by ATC that he did not contact the tower in a timely manner and violated the Class Delta.