Since September 11, 2001, which attack method has NOT been attempted against an airport or airline?

The correct response highlights that cyber attacks on booking systems have not been attempted against an airport or airline as an attack method since September 11, 2001. The nature of modern aviation security threats has largely focused on physical attacks and direct confrontations, like in-flight hijackings, terminal bombings, and threats targeting personnel such as pilots.

Cyber attacks, while a growing concern across many sectors, including transportation, have not yet manifested in the context of targeting the core operational abilities of airlines as directly as the other methods. The emphasis since 9/11 has been primarily on preventing direct physical threats that could cause immediate harm to passengers, staff, or aircraft, which helps clarify why cyber attacks have not been historically attempted in the same way. Understanding the evolution of attack methods and the focus on aviation security can help better anticipate and mitigate risks in the future.