Final answer:
Before an aircraft fuel tank can be repaired by welding, it must be cleaned, inspected for leaks, and prepared to eliminate any fuel vapors or residue.
Step-by-step explanation:
To repair an aircraft fuel tank by welding, several steps must be taken to ensure safety and efficiency. First, the tank must be thoroughly cleaned and purged of any remaining fuel vapors or residue. This is crucial to prevent any explosions or fires during the welding process. Next, the tank should be carefully inspected for any leaks or damaged areas that need to be repaired. Once these preparations are complete, the tank can be welded using appropriate welding techniques and materials.
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