Date: 201708
Local time of day: 1201-1800
Location: ZLA.ARTCC, CA
Flight conditions: VMC
Weather elements / visibility: Thunderstorm; 10
Light: Daylight
Aircraft: Small Transport
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Flight phase: Descent
Airspace: Class E ZLA
ATC / advisory: Center ZLA
Reporter organization: Corporate
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion; Situational Awareness
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Requested ATC Assistance / Clarification; General Flight Cancelled / Delayed
Contributing factors: Procedure; Human Factors; Airspace Structure; Weather
Primary problem: Weather

Narrative: Another pilot and I on board experienced an incident with L.A. Center while approaching the San Diego International Airport. The incident occurred when L.A. Center assigned our aircraft to fly direct to the IFR fix; JONDA then direct to the San Diego International Airport (SAN); which was our final destination. JONDA (IFR Fix) is located 55 nautical miles southeast of the San Diego International Airport just north of the Mexican/USA border. Our aircraft was flying on a heading direct to JONDA (IFR fix) from the north. L.A. Center then told our aircraft to maintain present heading once we were approximately 10 nautical miles north of JONDA (IFR Fix). Our aircraft along with multiple other aircraft approaching the San Diego International Airport were trying to maneuver around a large wall of thunderstorms that were located to the east of the San Diego County area.L.A. Center had most of the aircraft approaching the San Diego International Airport fly south close to the border of Mexico to deviate around the thunderstorm cells; then head inbound to the San Diego International Airport. While our aircraft was quickly approaching JONDA; maintaining our southerly heading to the Mexican border; our L.A. Center frequency became highly saturated with radio calls. Our L.A. Center controller kept getting stepped on while making transmissions to other aircraft. Also; two to three aircraft were calling at one time to get a hold of our L.A. Center Controller. Our controller even stated that two aircraft are calling at once and to say again because he did not receive the transmissions clearly from those two other aircraft. Our aircraft was still maintaining our present southerly heading that L.A. Center told us to fly; but we were quickly approaching the ADIZ borderline between Mexico and the United States. My other pilot and I tried reaching our L.A. Center Controller multiple times; but our transmissions kept getting blocked by other aircraft and the L.A. Center Controller together.We tried approximately 20 attempts to get a hold of our L.A. Center Controller; but were not able to. We started calling our controller once we were about 5 nautical miles to the North of JONDA (IFR fix) because we knew we were getting close to the ADIZ. The other pilot and I thought that the controller became too saturated with radio calls and forgot about our aircraft and our current position of our aircraft; which was very close to the ADIZ. Once we passed JONDA (IFR fix) on our assigned southerly heading; we were now 5 nautical miles from the North of the ADIZ and were soon going to pass the ADIZ without any sort of clearance or permission to cross the border of Mexico since our aircraft's final destination was San Diego International Airport; a United States domestic destination.Myself and other pilot kept trying and trying multiple times now; once we were quickly approaching the ADIZ; but the L.A. Center frequency was still very saturated with communication amongst the Controller and several other aircraft. Approximately 2-3 nautical miles north of the Mexico/United States ADIZ; myself and other pilot both decided to deviate and make a turn to the right on a westerly heading to avoid crossing the ADIZ from the north in VFR flight conditions. Once rolling out on the westerly heading we tried calling L.A. Center two-three more attempts and after the third attempt we were able to get a hold of the controller. We told the controller that we had to make a right turn to the west to avoid crossing the ADIZ into Mexico and tried multiple times calling on the frequency; but it was too saturated with transmissions between other aircraft and the controller.The L.A. Center controller then acknowledged to us that he was capable of having aircraft cross the ADIZ due to the thunderstorms in the area; but myself and other pilot had no knowledge of that information and were never communicated that information until after we made the turn to the westerly heading to avoid the penetration of crossing the ADIZ. L.A. Center then told us to fly on a heading of 255 degrees and expect radar vectors to San Diego International from that point. Our aircraft then was assigned a different Air Traffic Control frequency and made it safely to our destination of the San Diego International Airport.




Synopsis: A corporate pilot reported turning away from the Mexico ADIZ airspace after being unable to contact the Center due to frequency congestion.