Date: 201807
Local time of day: 1201-1800
Location: MYF.Airport, CA
Flight conditions: VMC
Weather elements / visibility: Clear; 10
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Landing
Reporter organization: Personal
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Human factors: Situational Awareness; Confusion; Communication Breakdown
Second reporter function: Trainee; Pilot Flying
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Human Factors

Narrative: I was acting as CFI on a flight Review Flight for a certified Private Pilot with an Instrument rating. [The pilot] was acting as PIC for the whole flight and operating radios. As CFI I was having him perform required tasks for a flight review and to get him current. Upon returning to ZZZ our point of departure PIC unintentionally performed touch and go on 28R when Tower had cleared him to land on 28L. Both PIC and CFI were shocked that somehow we had missed the correct clearance. Upon landing PIC called [the Tower] and gave his name and phone number. I; as CFI; proceeded to research the situation further by pulling up the ATC recording to determine where miscommunication happened; that led to a possible pilot deviation under my supervision. Initial Call by PIC - [pilot] requests landing with information. Initial Tower Response - make straight in 28R. I inform PIC to correct his call and asked him to request touch and goes. PIC requested touch and goes. No initial response from Tower due to traffic load. Minute later Tower asked; 'who asked for touch and goes?' PIC responds [with abbreviated tail number]. No immediate response from the Tower. Eventually; Tower responds with a clearance for [a similar abbreviated call sign] #2 Cleared touch and Go 28R. PIC flying responds #2 Cleared touch and go 28R. An incorrect call by PIC responding to a clearance for a similar sounding tail number. As CFI I did not hear the initial call sign only the [letter]. There was no correction by the Tower that PIC read back wrong clearance for a similar sounding tail number. PIC proceeds to line up for touch and go on 28R.On short final Tower gives clearance [with full call sign to] make short final cleared to Land 28L. PIC responds Cleared to land. As CFI I did not hear the Tower give 28L due to congested and blocked communication. The student gave incomplete clearance read back without runway assignment. Tower did not respond to correct and requesting full clearance read back. PIC continued to perform touch and go on 28R upon turning right crosswind to downwind; Tower told PIC that next time he did a go-around he needed to communicate his intentions. It was apparent Tower was unaware of landing on the wrong runway or where we were until on right downwind for 28R. Upon the confusion; CFI took the radio and asked Tower to clarify clearance. Tower confirmed clearance was to land on 28L. PIC received clearance to land on 28R; upon which was given a number for the Tower due to the possible pilot deviation. What I believe caused this possible deviation? Multiple errors by PIC; CFI; and Tower. Due to heavy congested airspace; radio communications; and incomplete and wrong radio calls that went uncorrected by Tower. Errors by Pilot: Reading Back incorrect and incomplete clearances. Not asking for clarification when airspace and radio were busy. Errors by CFI: Failure to ask Tower for clarification for clearance amidst busy and congested pattern and radio communications. As CFI my attention was outside the aircraft scanning for traffic which took my attention away from clearly hearing the communications when my student made incorrect and wrong readbacks. Errors by Tower: Initial clearance was given for straight in 28R. According to ATC recordings; next to actual clearance that was given when we were already lined up short final 28R. This clearance was given late and appeared Tower had lost [the aircraft] amidst busy pattern. Tower also failed to correct PIC's wrong clearance for #2 Cleared to land 28R miles earlier; and failure to have PIC read back full clearance with runway number. The problem was a miscommunication and misunderstanding of clearance between PIC; CFI; and Tower due to task saturation; busy airspace; and busy communications. What will be done to correct the situation. As the CFI I will take more diligence to maintain a sterile cockpit when providing instruction to clarify clearances when thereis any doubt or miscommunication. When airspace and communications are busy I will use extreme caution and take extra time to listen to clearances even when flying with certified pilots. I will provide my student further instruction concerning Radio Communications and Clearances; Airport Operations; Runway Incursions; Traffic Avoidance. As to the Tower. Often ZZZ gets extremely busy with 2 parallel runways in use. Many of the flights in and out of ZZZ are due to flight instruction. As a result communication with Tower becomes extremely difficult; with calls often being missed; stepped on; and miscommunicated. It has been a procedure by ZZZ Tower to split the two runways on different frequencies. In my opinion; the split of frequencies should have occurred when a single Tower operator started missing calls. Upon our downwind leg for final landing on 28R the Tower then decided to split the runway frequencies. If this had been done earlier it would have been easier for PIC; CFI; and Tower to communicate and clarify the correct clearance.


Second narrative: [Report narrative contained no additional information.]


Synopsis: C172 flight instructor and pilot reported performing touch and go landing on one runway when clearance had been a full stop landing on a different runway.