I am working on using the FAA TFR list to restrict drone flights and all of the entries I have examined have an "Airspace Definition" that reads like "Altitude: From the surface up to and including 17999 feet MSL." Presumably, aircraft can fly over such a TFR at 18,000 feet and above.
My question is are there ever TFRs that aircraft can fly under? They would read something like, "Altitude: From 5000 feet up to and including 17999 feet MSL."
Yes. The TFR over Beale Air Force Base (BAB) is defined as:
From and including 4100 feet MSL up to and including 18000 feet MSL.
Note how this TFR is essentially an extension of the Class C airspace from its charted ceiling up to the beginning of Class A airspace. The requirements to enter the TFR are just: Be on an ATC-assigned discrete code, and maintain two-way comms with ATC.
Note also that this is one of many "temporary" flight restrictions which are in reality quite permanent. It isn't so permanent as, for example, the Disneyland and Disney World "T"FRs, which are so permanent that they're highlighted on the printed VFR sectional. But the Beale "T"FR does get re-issued every six months or so.
This is the exception which proves the rule; I'm not aware of any other TFRs which begin higher than the surface.
