What is required equipment to operate IFR on extended over-water operations under 14 CFR 135?

• A. At least one long-range navigation system.
• B. At least two approved independent navigation systems; IFR requires one marker beacon receiver and one ILS receiver; RNAV, if used to meet requirements, must be authorized in the operator's OPS.
• C. No navigation equipment is required.
• D. Only RNAV navigation is required.

Answer: (B)

Redundancy in navigation is required for IFR over-water operations. For extended over-water flights under 14 CFR 135, you must have two approved independent navigation systems so that a failure of one system doesn’t leave you with no trusted navigation capability, which is critical when there are no visual references.

The way this is typically satisfied is by having one marker beacon receiver and one ILS receiver as independent sources of navigation. If you intend to use RNAV to meet this requirement, it must be authorized in the operator’s operations specifications, ensuring it’s an approved method for your operation.

So, the setup ensures you have two separate, approved navigation sources, providing essential redundancy for IFR flight over water. The options that omit this redundancy or rely solely on RNAV without operator authorization don’t meet the rule.