FAA AMT Airframe Practice Exam 2026 – All-in-One Study Guide to Master Aviation Maintenance Technician Certification!

A welding torch backfire may be caused by a loose tip because a loose tip can create a gap between the tip and the torch body, allowing oxygen to mix with the fuel gas in the torch. This mixing can result in a sudden ignition of the mixed gases, leading to a backfire. Options A, C, and D are not correct because they do not directly contribute to the backfire in a welding torch.