Description should include 14 CFR § 91.3, "In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency." Description should also include the following:

In emergency conditions requiring immediate action for the protection of life or property, the certificate holder may deviate from any requirement of subpart D of this part, or the Airport Certification Manual, to the extent required to meet that emergency.
Each certificate holder who deviates from a requirement under this section must, within 14 days after the emergency, notify the Regional Airports Division Manager in writing of the nature, extent, and duration of the deviation.
Refer to 14 CFR § 139.113, Deviations, for more information.

PLT394 and PLT403

Process/Skill Questions:

When might a pilot need to deviate from regulations?