It’s strongly recommended that you cover your aircraft with your own policy. Some FBO’s will carry hangarkeeper’s hull coverage (which is designed to protect the FBO in the event of damage to an aircraft under the care of but not owned by that FBO). Many do not carry hangarkeeper’s coverage. Additionally, even if the FBO’s policy includes the proper Hangarkeeper’s coverage, it may not pay out for certain types of losses, like those resulting from windstorm, vandalism, or mechanical failure, for example. If the FBO is not legally liable for the loss, the insurance company might not pay.