Who should attend. The course is designed for those who may have to conduct or participate in an aircraft accident investigation. This may be in the role of official investigator for a State or as an accredited representative/technical advisor of a manufacturer, operator or service provider.
Before electronic calculators, converting square varas (at 1 vara = 32.8748 inches) to acres was a tedious job. But if 1 vara = 33 1/3 inches, 3 varas are exactly 100 inches, 36 varas are exactly 100 feet, and 108 varas are exactly 100 yards. An easy division and some shuffling of the decimal point do the job.
For rafters spaced 20 or more inches apart, 1/2- or 5/8-inch plywood is recommended. The most common rafter spacing is 24 inches, and 5/8-inch plywood is recommended for that. It will support roof loads for most situations and is the standard for most roof applications. Roofs with very heavy loads may require 3/4-inch thickness.