An instructor reported entering class D airspace before contacting tower after TRACON VFR flight fol...

Narrative:

During a local training flight in VMC; we had been participating in flight following with joshua approach and were squawking a discrete transponder code. After completing several training maneuvers; at approximately 13 miles northwest of wjf; we advised joshua approach that we were proceeding to william J. Fox field for some touch and go's with information alpha; and they acknowledged. We began a descent from 4500 ft MSL to traffic pattern altitude and completed the descent checklist. At this point; we were inbound to the airport on a 45 entry for runway 24. At approximately 5 DME (GPS) from the airport; still squawking our assigned code; joshua had not yet told us to contact the tower; so we requested the switch. Joshua simply advised us to contact the tower. The trainee changed frequencies and attempted to contact fox tower; and when we received no reply; I noticed that she had set the frequency incorrectly. She then set the correct frequency and contacted the tower. At that time; our DME read 3.2 miles from the airport. As tower was responding to her contact to verify our position; the TCAS system alerted us to traffic at 12:00; same altitude; one mile. As we did not have the traffic in sight; we executed a climbing left turn to avoid the downwind leg. The tower then instructed us to make right traffic for runway 24 and we re-entered the pattern. After several touch and go's; we made a full stop and taxied back to runway 24. I contacted ground and explained the sequence of events during our arrival and asked for their advice. When the controller learned that we were with joshua on flight following; he explained that; unlike IFR; VFR aircraft must avoid class delta airspace until contact with the tower has been established. Having done much of my flying and instructing in and around class charlie airspace; I had incorrectly assumed that; since we were in contact with approach control and on a discrete transponder code; we were legal to enter class delta airspace. I now understand the difference between IFR and VFR arrival procedures; and will be sure to ask for the change to tower frequency at a distance that will allow for the switch before the airspace is encountered.

Original NASA ASRS Text

Title: An Instructor reported entering Class D airspace before contacting Tower after TRACON VFR flight following. The Tower Controller counseled the pilot about who is responsible for Tower communications while VFR.

Narrative: During a local training flight in VMC; we had been participating in flight following with Joshua Approach and were squawking a discrete transponder code. After completing several training maneuvers; at approximately 13 miles northwest of WJF; we advised Joshua Approach that we were proceeding to William J. Fox Field for some touch and go's with information Alpha; and they acknowledged. We began a descent from 4500 FT MSL to traffic pattern altitude and completed the descent checklist. At this point; we were inbound to the airport on a 45 entry for Runway 24. At approximately 5 DME (GPS) from the airport; still squawking our assigned code; Joshua had not yet told us to contact the Tower; so we requested the switch. Joshua simply advised us to contact the Tower. The trainee changed frequencies and attempted to contact Fox Tower; and when we received no reply; I noticed that she had set the frequency incorrectly. She then set the correct frequency and contacted the Tower. At that time; our DME read 3.2 miles from the airport. As Tower was responding to her contact to verify our position; the TCAS system alerted us to traffic at 12:00; same altitude; one mile. As we did not have the traffic in sight; we executed a climbing left turn to avoid the downwind leg. The Tower then instructed us to make right traffic for Runway 24 and we re-entered the pattern. After several touch and go's; we made a full stop and taxied back to Runway 24. I contacted Ground and explained the sequence of events during our arrival and asked for their advice. When the Controller learned that we were with Joshua on flight following; he explained that; unlike IFR; VFR aircraft must avoid Class Delta airspace until contact with the Tower has been established. Having done much of my flying and instructing in and around Class Charlie airspace; I had incorrectly assumed that; since we were in contact with Approach Control and on a discrete transponder code; we were legal to enter Class Delta airspace. I now understand the difference between IFR and VFR arrival procedures; and will be sure to ask for the change to Tower frequency at a distance that will allow for the switch before the airspace is encountered.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	866805
Time
Date	200912
Local Time Of Day	0601-1200
Place
Locale Reference	WJF.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Direct
Flight Plan	None
Person 1
Function	Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 110 Flight Crew Total 7930 Flight Crew Type 203.5
Events
Anomaly	ATC Issue All Types Airspace Violation All Types Conflict Airborne Conflict Deviation - Procedural Clearance Deviation - Procedural FAR
Miss Distance	Horizontal 5000 Vertical 0

An instructor reported entering class D airspace before contacting tower after TRACON VFR flight following. The tower controller counseled the pilot about who is responsible for tower communications while VFR.