Electric air taxis and delivery drones could soon become a common sight in cities around the world.
These aircraft promise faster travel, less traffic on the roads, and lower carbon emissions than traditional vehicles.
However, one major challenge still stands in the way of widespread use: noise.
A new study from the University of Bristol suggests that a simple change to landing pad design could make these aircraft much quieter during takeoff and landing.
The findings, published in Applied Acoustics, could help shape the future of urban air travel by making it more acceptable for people living and working nearby.
Unlike traditional airplanes, electric vertical takeoff and landing aircraft, known as eVTOLs, can rise straight into the air and land vertically, much like helicopters.
They are expected to be used as air taxis, emergency transport, and delivery vehicles in the coming years.
These aircraft will need special landing areas called vertiports. A vertiport is similar to a helipad but is designed specifically for electric aircraft.
Researchers now believe that the design of these landing pads could play an important role in reducing noise.
The study focused on a problem known as the “ground effect.” This happens when an aircraft flies very close to the ground during takeoff or landing.
Air pushed downward by the rotating blades hits the ground and bounces back upward. This creates areas of high air pressure beneath the aircraft, making the blades louder and increasing the overall noise.
Instead of using a solid concrete landing pad, the researchers tested a landing surface with many small holes, known as a perforated surface.
The idea is simple. Rather than forcing all of the air to hit a solid surface, the holes allow some of the airflow to pass through the landing pad.
This reduces the buildup of high-pressure air beneath the aircraft. At the same time, the holes reduce the way sound waves bounce off the ground. Together, these effects help make the aircraft noticeably quieter.
The results were impressive. The researchers found that perforated landing pads reduced the noise produced by the aircraft’s blades by as much as 15 decibels.
Overall sound levels were reduced by up to 7 decibels, a difference that would be clearly noticeable to people nearby.
Lead researcher Dr. Esmaeel Masoudi explained that the holes in the landing surface interrupt the airflow that normally creates extra noise during takeoff and landing. Instead of crashing into a solid surface, part of the airflow passes through the openings and loses energy before it can create loud sound.
The researchers believe this shows that solving the noise problem is not only about improving aircraft design. The infrastructure on the ground is just as important. Future vertiports, rooftop landing pads, and drone delivery hubs could all be designed with perforated surfaces to reduce noise in busy urban areas.
As cities prepare for a future with electric air taxis and delivery drones, quieter landing pads could make these new forms of transportation more acceptable to local communities.
By combining smarter aircraft with better-designed infrastructure, engineers hope to create cleaner, quieter, and more sustainable skies for everyone.
