How are IFR flight plans canceled at towered airports?

The correct answer highlights that IFR flight plans are typically canceled automatically by Air Traffic Control (ATC) upon landing at towered airports. This procedure is designed to streamline the process of managing aircraft in the busy environment of a towered airspace. Once an aircraft safely lands and is in contact with the tower, the control tower personnel will usually handle the cancellation of the IFR flight plan without necessitating extra actions from the pilot. This automatic cancellation helps ensure that pilots are not required to manually manage their flight plans once they have safely concluded their flight.

In this context, if pilots had to cancel their flight plans manually or by filing a new plan, it could lead to confusion or miscommunication, especially in high-traffic environments. Therefore, the automatic cancellation by ATC upon landing is a practical and efficient approach that enhances safety and operational efficiency.