GBT What?

A new NOTAM showed up for SQL that I hadn't seen before.

Navigation NOTAMs

San Carlos CA [SQL]: October NOTAM #6

Navigation GBT out of service

The flight briefer wasn't able to explain it, essentially saying it isn't anything I needed to be concerned about. I asked the tower and they said they really didn't know the details but it wasn't anything that impacted their approaches (e.g. GPS).

The Pilot/Controller Glossary gives some insight:

GROUND-BASED TRANSCEIVER (GBT)- The ground-based transmitter/receiver (transceiver) receives automatic dependent surveillance-broadcast messages, which are forwarded to an air traffic control facility for processing and display with other radar targets on the plan position indicator (radar display).

Looks like it is related to ADS-B.

So that's how they do it!

Has this happened to you? You are planning a flight and calculating the W&B and determined how much fuel you can carry to be within the W&B limits. You get to the plane and find out that there happens to be more fuel than what you can carry or need. You can always tell your passengers that one or more of them can't go or consider other options (reduce the baggage carried) to accommodate for the extra fuel. Another option is to drain fuel. Recently I saw how this can be done. Another member was taking a trip in a 182 with 4 passengers and needed to have the fuel at 50 gallons or less. The plane had about 63 gallons. They requested WVFC MX to drain the fuel. To do that, they cut the safety wire holding the wing fuel drain valve, then unscrewed that drain valve while standing ready with a funnel, attached to tubing that drained the fuel into a fuel container. Once the appropriate amount of fuel was drained the fuel drain valve was quickly screwed back in to stop the flow of fuel. Then the safety wire was reattached with a special tool that puts a nice twist on the wire.


What happens to the fuel that was drained? It doesn't go back into a plane but can be used in some vehicles.
Who pays for the fuel drained? As near as I can tell, the owner eats the cost of the drained fuel.