Date: 201403
Local time of day: 1201-1800
Location: SDM.Airport, US
Flight conditions: VMC
Weather elements / visibility: 25
Light: Daylight
Aircraft: Small Aircraft; High Wing; 1 Eng; Retractable Gear
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Final Approach
Airspace: Class D SDM
ATC / advisory: Tower SDM
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Confusion; Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Landing Without Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control; Person Flight Crew
When detected: Aircraft In Service At Gate
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: I was on an active international VFR flight plan returning from Mexico under positive radar control of Tijuana Approach. Just prior to the US ADIZ and overhead Tijuana International Airport (MMTJ) at 2;000 FT MSL; Tijuana Approach cleared me direct to the base leg of San Diego Brown Field (SDM) Runway 8 left and directed me to 'switch to Tower'. Despite flying in this region for over 30 years; I have never previously landed at SDM. Therefore during preflight planning I reviewed the latest revision of the Airfield Directory (AF/D dated Mar 2014) (using the Foreflight program on my iPad). I also had printed a copy of the SDM airfield information [from the internet] with me for hard copy backup which I had read before leaving on the trip earlier in the week. Both of these documents state that SDM Operations 'Attendance is M-F 0700-2000; CLSD WKENDS'. Therefore; given that I was arriving at SDM on a weekend afternoon; when Approach dropped me off to 'Tower' I switched to the published SDM UNICOM frequency of 122.95 and made the standard UNICOM calls for 1) my right base entry to Runway 8L; 2) on final Runway 8L and 3) clear of the runway. At the U.S. aircraft holding area; I was informed by the Agent that the Tower wanted to talk to me about why I landed without clearance to land. I called the Tower and provided the above statement/information to the Tower Controller on duty. During our phone conversation the Controller agreed that the SDM AF/D 'is unclear and that one could easily be confused by its language on when the Tower is open.' Despite this; he stated that he had to write up this incident since the Tower was open and I landed without clearance.Contributing factors: 1) Ambiguous and nonstandard AF/D descriptive language. 2) Close proximity of San Diego Brown Field and Tijuana International. 3) Controller handoff procedure at Tijuana Approach which is different than U.S. control handover practices. My post-incident research revealed that; with only one other exception I found (MYF); the Tower controlled airfields in SOCAL operate like SDM but the other airport AF/D operations or remarks sections do not say closed on the weekends. These other airport AF/D remarks state that they are attended 'Continuously' or have specific hours but do not limit the days of the week. My home field operates exactly like I now know that SDM operates -- the Tower is open everyday; however; my home airport AF/D states 'Operations Attendance XA00-XO00.' I am of the opinion that inconsistencies and nonstandard AF/D language may lead to further aviator confusion and therein creates the potential for a future aircraft mishap. Actions/Recommendations: 1) NASA to suggest that the FAA standardize AF/D language used for operations attendance -- specifically that the 'attendance' reflect the Controller Tower operating hours (and operating days if these are limited). 2) FAA to contact the Mexican ITU officials and recommend that Tijuana Approach Controllers specifically state the SDM Tower frequency to switch to when an aircraft under their positive control is handed off to SDM. (This is especially important given that the two airfields are only 2 miles apart.) 3) In accordance with recommendation #1; FAA to immediately publish a change notice for both Montgomery Field and San Diego Brown field which should clarify that both of these Control Towers are active seven days a week (as is the surrounding Class D airspace). 4) FAA to conduct a review of AF/D language on Tower operating/attendance hours and issue additional change notices as required.




Synopsis: A pilot was handed off from MMTJ Controllers and told to contact SDM. The pilot erroneously called UNICOM instead of CTAF because the AF/D stated the Tower was closed on weekends. After landing; he was told to contact Tower where a Controller stated the Tower was in operation seven days a week. The reporter states the AF/D is in error.