I heard ground controller at KPHL say taxi to spot so and so? What do they mean by this during taxi procedures.
A spot will be just a place on the airport surface. Generally these are termed as specific locations such as the blank ramp for example. A “Hot Spot” is a specific location that is a known hazard for aircraft for one of numerous reasons. These reasons could be from a history of confusing pilots or just from common sense and logic. Some Hot Spots are designated where several taxiways and or runways intersect. They can be Considered hazardous because pilots in the past have confused taxiways for runways and/or runways for taxiways. Some Hot Spots are considered hazardous because Towers view of that area is blocked by obstacles or obstructions. Known Hot Spots are marked and numbered on some airport taxi diagrams to alert pilots of the hazard.
The airport layout is represented in terms of aprons, taxiways, Ramps, gates, bays and sometimes uncommon words like loops, spots etc. The same is very clearly marked on airport charts and is easily locatable if one cares to look. Hot spots are typically intersecting taxiways where there is a possibility of conflict of aircraft on the move. These are also marked on the airport charts and are recommended to be briefed between pilots.