Do not face a landing helicopter within 100 feet unless you are wearing?

The correct answer is wearing goggles when facing a landing helicopter within 100 feet. This is crucial because helicopters generate significant rotor wash and debris can be blown around at high speeds, which can cause serious eye injuries. Goggles protect the eyes from flying particles, dust, and debris that could be dislodged by the helicopter's rotor wash, ensuring the safety of personnel in the vicinity.

While other forms of protective equipment such as safety helmets, hearing protection, and face shields are important in various contexts around helicopters, they do not specifically address the immediate risk to the eyes posed by debris in the helicopter's rotor wash. Therefore, wearing goggles is particularly important for maintaining visibility and protecting one of the most vulnerable parts of the body when in close proximity to landing or departing helicopters.