Which area is NOT suitable for a helicopter landing zone?

A helicopter landing zone needs to meet specific criteria to ensure safe landings and takeoffs. Urban centers are often unsuitable for helicopter operations primarily due to safety concerns and space limitations. The presence of tall buildings, power lines, and other structures can create hazards for helicopters during landing and takeoff maneuvers. Additionally, urban areas typically have higher population densities, which increases risks to civilians in case of an emergency or unintended landing.

In contrast, flat open spaces, hilltops, and deserted fields generally offer the necessary space and clear approach paths for helicopters, making them more conducive to safe operations. Flat surfaces provide stability, while hilltops can allow for better visibility and avoidance of obstacles. Deserted fields also offer ample space with less risk of encountering pedestrians or vehicular traffic. Thus, urban centers are the least suitable for helicopter landing zones compared to these alternatives.