Inflight
turbulence

Inflight turbulence is an unsolved problem for aviation impairing comfort, safety, and economy of flight operation.

Existing solutions are insufficient:

The aviation industry aims to avoid turbulence by means of improving forecasts and weather models, as well as weather up- and downlinks. However, rerouting, change of flight level and logistic unreliability lead to wasting valuable resources, such as energy, CO2 emissions, and time. For a number of  flights avoiding turbulence is not possible, especially for short-range low-level flights. A radical alternative for passengers to avoid  inflight turbulence is switching to ground transportation.

Based on certification requirements, wings are reinforced to withstand typical gusts and turbulence. Still, to not exceed load limits the airspeed needs to be reduced in turbulent air to ensure structural integrity. Flying throught turbulence passengers are exposed to intense and rapidly changing accelerations, leading to discomfort and fear. Without seatbelt flight crew and passengers regularly get injured in severe turbulence, leading to the majority of severe injuries of airline flights and in some cases even to death. In consequence of constantly improving turbulence forecast and data, flight into known turbulence is likely to be restricted in future, similarly to flights into known icing or low-visibility.

Gust load alleviation systems aim to reduce wing root moments, commonly by symmetric aileron deflection. The so far achieved alleviation in the order of 10% is aimed to be further improved for envisaged structural mass reduction. Given its limited authority and reactive nature, so far considered control systems show no significant improvement of passenger comfort and are not sufficient to effectively cope with increased levels of atmospheric turbulence.

To substantially reduce the negative impact of turbulence, new solutions are needed, which sufficiently reduce turbulence loads felt by passengers.

Impact on Small Aircraft Operation

Small aircraft operation in low atmosphere is considerably affected by very frequent and strong turbulence typically present in ground proximity. Light weight aircraft are hit strongly by turbulence, similarly to feathers in the wind.

Comfort and Passenger Experience
Safety and Perception of Safety

Assistance System with limited range and authority already sufficient

Common types and causes of turbulence

Clear air

Rapid changes in speed and/or direction near fast moving bands of air

Wake

When an aircraft passes through turbulence caused by an aircraft in front of it

Thunderstorm

Violent updrafts and downdrafts caused by storms

Mountain wave

When air is blown over a mountain causing updrafts and downdrafts

Impact on Advanced Air Mobility

eVTOL especially light, still fast cruise speed. Even more for the operation in urban canyon of very light vertical take-off and landing vehicle (eVTOL) as desired for advanced air desired for mobility (AAM).

Customer Acceptance
Availability of Service

Assistance System with limited range and authority already sufficient

Impact on Large Aircraft Operation

Avoiding turbulence

Climb to fly over

Descend to fly under

Slow down to fly through

Change route to fly around

Additional fuel means additional CO2 emissions

Direct flight, optimized flight routing
Mass reduction and aerodynamic optimization
Logistics

Needs fail-operational capabilities with sufficient range and authority

Inflight Turbulence
on the Rise

Global Warming: stronger winds, more thermal activity, jet streams