When flying on an airplane, you can be exposed to both UVA and UVB rays, although the intensity of UVB rays decreases with altitude due to the Earth's atmosphere. However, UVA rays remain relatively constant and can penetrate through aircraft windows.

1. UVA Rays: These rays are present at relatively consistent levels throughout the day and can penetrate deeper into the skin compared to UVB rays. UVA rays are responsible for causing skin aging, such as wrinkles and age spots, and they can also contribute to skin cancer development. UVA rays can penetrate through aircraft windows, exposing passengers to sun damage during flights.

2. UVB Rays: These rays are partially absorbed by the Earth's atmosphere, so their intensity decreases with altitude. However, UVB rays can still reach aircraft windows and cause sunburn, especially during longer flights or at higher altitudes. UVB rays are primarily responsible for causing sunburn and skin cancer.

The reason sun exposure can be worse on an airplane is due to several factors:

• Altitude: Flying at high altitudes exposes passengers to higher levels of UV radiation because there is less atmosphere to absorb and filter the rays. This increased exposure can lead to greater sun damage over time.

• Window Design: Most aircraft windows are designed to block UVB rays but not UVA rays. While UVB rays are more associated with sunburn, UVA rays can penetrate deeper into the skin, causing long-term damage such as premature aging and skin cancer.

• Duration of Exposure: Flights, especially long-haul flights, can expose passengers to prolonged periods of UV radiation. Even though individual exposures might be brief, the cumulative effect of multiple flights over time can contribute to skin damage.

To protect yourself from sun damage while flying, consider taking the following precautions:

1. Use Sunscreen: Apply a broad-spectrum sunscreen with SPF 30 or higher to any exposed skin, including your face, neck, and hands. Reapply sunscreen every two hours, especially during long flights.

2. Wear Protective Clothing: Consider wearing long sleeves, pants, and a wide-brimmed hat to shield your skin from UV radiation.

3. Use Window Shades: Close the window shades to reduce direct sun exposure during the flight, especially if you're sitting by a window.

4. Use Sunglasses: Wear sunglasses with UV protection to shield your eyes from harmful UV rays.

By taking these precautions, you can help minimize your exposure to UV radiation and reduce the risk of sun damage while flying.