Date: 201511
Local time of day: 1201-1800
Location: SAT.Tower, TX
Flight conditions: VMC
Light: Daylight
Aircraft: Helicopter
Operator: Air Taxi
Operating under: Part 135
Flight plan: VFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class C SAT; Class D RND
ATC / advisory: Tower SAT
Reporter organization: Air Taxi
Reporter function: Single Pilot; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Workload; Communication Breakdown
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Chart Or Publication; Airport
Primary problem: Procedure

Narrative: I was dispatched to a location approximately 60 miles east. After departing; I contacted the San Antonio Control Tower; which is the normal procedure and advised them that I was responding to a call. The Tower advised me to remain south of the approach end of runway 4; and then to proceed. I transitioned south of runway 4 and once clear; I made a turn on course. This route typically takes us east through the Randolph AFB area. While still in contact with San Antonio; and a couple miles east of Randolph AFB; I requested to cancel services with ATC. I did this because I noticed San Antonio was very busy; due to RADAR issues; and I thought that one less aircraft to deal with would alleviate some of the congestion for them. On the return leg after picking up the passenger; I contacted San Antonio approach in bound and requested flight following. Again; this would take me through the Randolph AFB area; and at about 5 miles out from the Air Force base; ATC advised me to contact Randolph Tower. I was surprised by this; because I had just completed the same exact flight profile on another call; and when I asked San Antonio Approach if Randolph was open today; which they typically are not on weekends; he stated that they were not open. I contacted the Tower and transitioned. Although I was in contact with San Antonio on the second call while in the Randolph area; I became concerned after coming through the area second time; because the field was now open; and I was not aware of it; or not advised by ATC. There are no NOTAMS indicating they would be open; and we generally always need to coordinate with San Antonio to determine their operating status. One of the issues with Randolph AFB; is the sporadic hours of operation; and the ATIS system for Randolph AFB operates on a frequency band that civil aircraft cannot access; further limiting our ability to ascertain the status of the field through traditional means. Furthermore; the Airport Facility Directory states that Class D service is available Mon-Fri; closed Sat-Sun and Federal holidays; other times Class E airspace. We are always in contact with San Antonio while operating in the area; but I felt that maybe in my attempt to free up the congestion for them; and my proximity to the base; I should have stayed with San Antonio a little longer in hindsight. I'm always very diligent on where I'm operating; and I generally always make every attempt to ascertain the status of my operating environment; probably even to the annoyance of the ATC personnel; but I should have not assumed the Tower was closed for the weekend as they typically are; even though out of habit; I did ask the status of the field on the earlier flight.




Synopsis: A Helicopter pilot departed SAT transiting east over RND Class E but during the return flight RND had become Class D without notification and not in accordance with the AFD stating Class E on weekends.