Definition
An FAA-issued Letter of Authorization, identified by the code C073, that grants an operator specific permission to conduct Enhanced Flight Vision System (EFVS) operations to 100 feet above the touchdown zone elevation in lieu of natural vision. The LOA C073 specifies the aircraft, EFVS equipment, training requirements, and operational limitations under which the operator may use EFVS to descend below the published Decision Altitude (DA), Decision Height (DH), or Minimum Descent Altitude (MDA) without the required visual references being visible to the unaided eye.
Plain English
A formal written approval from the FAA, with the reference number C073, that lets a specific operator use their Enhanced Flight Vision System to continue an instrument approach down to 100 feet above the runway, even when they can't yet see the runway with the naked eye.
Context Anchor
Seen in discussions of Enhanced Flight Vision System use during instrument approaches and the FAA approvals required before using those capabilities operationally.
Derivation
LOA stands for Letter of Authorization, the FAA's standard term for a written approval granting a specific operator permission to do something not covered by their basic certificate. The C073 is simply the FAA's catalog number for this particular authorization, the way each type of approval is filed and tracked.
Why Pilots Care
It authorizes lower approach minima and allows landings in weather conditions that would otherwise prevent completion of the approach.
Intuition Check
Do not read C073 as a runway code, chart minimum, or aircraft performance label. It is an FAA authorization paragraph tied to a specific operator’s approval.
Example Sentence 1
The chief pilot confirmed that all three Gulfstreams were listed on the company's LOA C073 before dispatching the EFVS approach into Aspen.
Example Sentence 2
With LOA C073 in hand, the crew continued the approach using EFVS when the runway lights became visible only at 150 feet.