No, it is generally not feasible or effective to use large water-scooping planes to fight skyscraper fires. These aircraft are designed for fighting widespread wildfires in open areas and are unsuited for the unique challenges of urban high-rise fires.

Key reasons why they are not used include:

Inaccurate Targeting: Water-scooping planes drop massive amounts of water over a large area, which lacks the pinpoint accuracy required for a specific floor or section of a skyscraper. This imprecision poses significant risks to the public, surrounding buildings, and ground personnel.

Structural Damage Risk: A sudden drop of thousands of gallons (tonnes) of water from a height would exert immense force, likely causing severe structural damage to the building's walls or roof, potentially leading to a partial or total collapse.
Fire Location and Access: Most skyscraper fires originate inside the building, not on the roof. The building structure would block the water from reaching the actual flames, making the drop ineffective.

Operational Constraints:

Water Source: Water-scooping planes require a large, unobstructed body of water (like a large lake or a section of the ocean, typically needing about a mile of clear space) to skim the surface and fill their tanks. Such a source is rarely available in dense urban environments.

Flight Conditions: Dense smoke columns and turbulent hot air rising from a high-rise blaze create hazardous flying conditions, impacting visibility and aircraft control.

Logistics: The time required to get the aircraft to the scene, find a suitable water source, and execute a drop makes them impractical for the rapid response needed in urban emergencies.

Fanning the Flames: The powerful downwash from helicopters (and to a lesser extent, the air disturbance from low-flying planes) could introduce fresh oxygen to the fire, potentially intensifying the blaze rather than suppressing it