Final answer:
The altitude 6,500 ft should be communicated on the radio as "six thousand five hundred feet" to ensure clear and accurate aviation communication.
Step-by-step explanation:
The proper way to say the altitude 6,500 ft on the radio is "six thousand five hundred feet." When communicating altitudes in aviation, it is standard to speak each digit individually to avoid confusion
For example, if a pilot or controller was referring to different altitudes such as 10,000 ft, 5,000 ft, or 2,000 ft, they would say "ten thousand feet," "five thousand feet," and "two thousand feet" respectively. It is important to articulate each number clearly and use the word 'feet' to ensure that the altitude is understood as a measurement of distance above sea level.