Aircraft data plates are Federal Aviation Administration (FAA) approved identifications for an aircraft. The plates are often metal and are etched with vital registration information about the aircraft. It includes the date of manufacture, model number, serial number, and registration number. All aircraft— from military grade to amateur built— are required by the FAA to display a data plate.
Title 14 CFR Part 45 lists the identification and registration marking requirements for an aircraft. The FAA states that the plates must be secured to the exterior of the aircraft. It must be legible to someone on the ground and not placed in a location where it will be defaced or removed during normal service. The plate must also be attached to the aircraft in a way that will prevent it from being lost or destroyed in case of an accident. It cannot be placed on removable surfaces, such as the door, it has to be located on the fuselage.
Metal photo photosensitive anodized aluminum is the best option for data plates because they resist corrosion caused by extreme environmental conditions. They are durable, lightweight, and resistant to extreme temperatures, sunlight, chemicals, etc. These plates have proven to be durable for more than 20 years.
The aircraft data plate is required to obtain a standard airworthiness certificate. If the plate is lost, stolen, or damaged the operator should seek a replacement from the original manufacturer. If, for some reason, obtaining it through them is impossible, the operator should contact their local Flight Safety Standards District Office or Manufacturing Inspection District Office and they will assist them in finding an approved replacement. Ordering them online is risky due to the inability to prove that they were produced by the manufacturer or an FAA approved alternative source.