Which checklist must be completed before engine start in the Warrior PA-28A?

The Before Start checklist must be completed before engine start in the Warrior PA-28A to ensure that all necessary pre-engine starting procedures are followed. This checklist includes critical tasks such as confirming that the fuel selector is set to the correct position, ensuring the throttle is set properly, and verifying that all switches are in the correct positions. Completing this checklist helps to ensure safety and proper operation of the aircraft by preventing potential issues that may arise if steps are overlooked.

The Pre-Flight checklist, while important, is focused on checking the aircraft's overall condition and preparing it for flight rather than specifically for the engine start. The Engine Run-Up checklist is performed after the engine has started to test engine performance and system functionality, and the Before Landing checklist pertains to preparations for landing, making them irrelevant for the initial engine start process.