A plane crash is a disaster in SimCity and SimCity 2000 which can either occur naturally or can be instigated by the player if they feel murderous.
A plane crash is where a plane is traveling above the city which loses control and starts spinning, eventually crash landing somewhere in the city. Small fires usually breakout around the crash site which can burn large areas if left alone.
In SimCity, if the player chooses the air crash option in the absence if an airport, this will only create an ordinary explosion and notifies the player of the explosion that happened.
Plane crashes can also occur in Simcity 2000 if a tall bulding such as a skyscraper or arcology is built close to the end of an airport runway, in which case a plane attempting to take off or land will soon crash into said structure and destroy it, along with starting a few fires.
The plane crash disaster was removed in SimCity 4 and SimCity (2013), presumably due to the terrorist attacks that occured on September 11, 2001. The disaster option was also removed from edited editions of SimCity 3000 following the attacks.