Can commercial airliners, such as the Boeing 747 or the Airbus 340, be caused to crash by turbulence?
Answer by Thomas Zerbarini:
Although it's very unlikely, it is possible.
The FAA has established turbulence classifications, or definitions, that pilots use to report the turbulence they experience. Light, Moderate, Severe and Extreme.
In severe turbulence, the aircraft may be damaged due to exceeding a structural limitation. In Extreme turbulence, an aircraft most likely will have been damaged due to exceeding a structural limitation. For this reason, pilots are required to report and document turbulence above severe as a pirep (pilot report), company incident report and make an entry in the maintenance log so that an inspection can be performed.
Here is a great article from AOPA Flight Training magazine discussing turbulence and maneuvering speed…