Date: 201501
Local time of day: 1201-1800
Location: MOB.TRACON, AL
Flight conditions: VMC
Weather elements / visibility: 50
Light: Daylight
Aircraft: Military Trainer
Operator: Military
Flight plan: VFR
Mission: Training
Flight phase: Initial Approach
Airspace: Class C MOB
ATC / advisory: TRACON MOB
Reporter organization: Military
Reporter function: Instructor; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Commercial
Human factors: Situational Awareness; Communication Breakdown
Anomaly: Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Airspace Structure
Primary problem: Human Factors

Narrative: On climb out from Airport ZZZ; I was VFR but under flight following from MOB TRACON. I told them my intentions to fly to WORIR then UMMAP which was the IAF for the RNAV 08 into 1R8 airport. I also informed TRACON that I was going to fly the Holding-In-Lieu-Of portion of the approach. TRACON's response was: 'Hold as requested'. WORIR and UMMAP are very close to each other; so once I hit WORIR heading 360; I informed TRACON that I would be making a left 270 turn in order to fly to UMMAP for the HILO which has an inbound course of 086. They said: 'Roger'. When I was approximately 2 miles west of UMMAP; my student became task saturated and the radios were busy; so I informed TRACON that I wanted to cancel flight following. I cannot remember for sure; but I think they said: 'Squawk VFR; frequency change approved'. I am certain that they didn't try to keep me on their frequency and maintain flight following during the approach. My student changed to ATIS to get an updated altimeter setting and then switched to the CTAF frequency for 1R8. He hit UMMAP and started the holding turn back out to the west. The holding pattern for the IAP depicts 4 nm legs. At approximately 3.5 miles and 2;000 feet MSL; I realized that I was very close if not already within the boundaries of the class C airspace ring of MOB and that I did not have the required 'Two-way' radio communication with TRACON but that I was cleared to 'hold as requested' minutes earlier. I made the turn inbound and mulled over calling up MOB TRACON after I had already left their airspace; re-entered it during the outbound hold; then exited again on the inbound hold. I did not call them to confess or clear up any confusion though as I could not think of how to communicate all this in a concise radio call that wouldn't jam the frequency for others. I was monitoring UHF guard for the whole flight but never heard anything from MOB on that frequency. I am unclear if I was in the wrong for re-entering Class C airspace while VFR during a HILO procedure of an instrument approach to which I had already coordinated with TRACON for. If I had to do it over again; I would have not terminated flight following until I was complete with the procedure and well clear of the Class C airspace of MOB.




Synopsis: Flight Instructor reports inadvertent entry into MOB Class C airspace during a practice RNAV 8 approach to 1R8 in VMC. The RNAV race track procedure turn may have taken the aircraft into the Class C.