Final answer:
In aviation, during the day under VFR, it's recommended for pilots to fly at least 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft; at night, higher minimum altitudes are generally required, with a 1,000 feet clearance in non-congested areas and 2,000 feet in congested areas.
Step-by-step explanation:
The question "How high above highest obstacle for day and night?" seems to concern aviation regulations with respect to altitude requirements when flying over obstacles during day and night times.
In aviation, specific altitude requirements must be met to ensure safe clearance over obstacles such as buildings, towers, or terrain. During daytime visual flight rules (VFR) flying, it is recommended that pilots maintain an altitude of at least 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft. For night flying under VFR, pilots must be even more cautious due to limited visibility, and regulations often require higher minimum altitudes.
To ensure safety, night VFR flying usually requires maintaining a buffer of 1,000 feet above obstacles in non-congested areas and 2,000 feet in congested areas. However, specific altitude requirements can vary depending on the country, local regulations, and type of flight operation, so it is important to consult the appropriate aviation authority or documentation for precise guidance.