What happens when lightning strikes a plane?

New research to address impact of lightning on aircraft composite materials.

Although lightning strikes are rarely the primary cause of accidents, they can cause costly delays and service interruptions - image courtesy of DFC.
Although lightning strikes are rarely the primary cause of accidents, they can cause costly delays and service interruptions - image courtesy of DFC.

Welsh scientists are working on a project to help improve the global aerospace industry by developing new ways of better protecting modern aircraft from lightning strikes.

The PROTEction of STructures from Lightning Strike (PROTEST) research project is a collaboration between EADS Innovation Works, Airbus, Hexcel, Cardiff University and the National Composites Centre. Funding for the project, to the tune of £2.6m, is to be provided by the UK’s innovation agency – Innovate UK, and The Aerosapce Technology Institute (ATI).

The PROTEST research project will aim to provide a better understanding of what happens when lightning strikes a plane and the impact of lightning on aircraft parts built from carbon composite materials.

According to Scientific American, a plane is usually struck by lighting at an extremity such as the nose or wing tip. The lightning is then conducted through the fuselage and the current then travels through the conductive exterior skin of the airplane and exits off another extremity, such as the tail. Pilots occasionally report temporary flickering of lights or short-lived interference with instruments.

Previous generations of aircraft were primarily made of aluminium, a very good conductor of electricity that provided a good safeguard against lightning. By making sure that no gaps exist in this conductive path, aerospace engineers assured that most of the lightning current remained on the exterior of the aircraft. Modern aircraft are increasingly made of composite materials that are significantly less conductive but that feature an embedded layer of conductive fibres, or screens, designed to carry lightning currents.

Researches at Cardiff University will study the mechanisms involved when lightning strikes the carbon composite materials and devise ways of making the materials safer and more reliable, therefore helping to improve the overall safety of modern aircraft.

Research for the project will be undertaken at the Cardiff University’s Morgan-Botti Lightning Laboratory – the only UK university-based lightning laboratory dedicated to aerospace research and testing.

In the US, the Electromagnetic Effects Lab at the National Institute for Aviation Research at Wichita State university in Wichita, KS has a lightning laboratory dedicated to aerospace research and testing. Researchers at the facility are also conducting research on lightning protection for composite materials and expect to work with such companies as NASA, Bombardier and Cessna to test new plane parts before they go into production.

PROTEST funded by government

Universities and Science Minister Jo Johnson made the funding announcement for the project during a visit to Cardiff University. Mr Johnson said the funding would help to further develop the world-class Welsh aerospace sector.

Jo Johnson, Universities and Science Minister with Professor Colin Riordan, Vice-Chancellor and Professor Manu Haddad, Director of the University’s Morgan-Botti Lightning Laboratory take a tour of the Cardiff University laboratory which will be home to a research project that has received government funding of $2.6m - image courtesy of the University of Cardiff.
Jo Johnson, Universities and Science Minister with Professor Colin Riordan, Vice-Chancellor and Professor Manu Haddad, Director of the University’s Morgan-Botti Lightning Laboratory – image courtesy of the University of Cardiff.

“As a One Nation Government we are backing science and innovation across the U.K,” he said.

“We want to be the best place in Europe to innovate which is why we are investing in Cardiff University’s unique project to create new ideas for developing Wales’ world-class aerospace sector.”

Head of Airbus Group Innovations UK, Ian Risk, said the PROTEST research project would help to provide a better understanding of the nature of lightning strikes and their effect on modern aircraft.

“This is a key project for the aerospace industry, allowing us to enhance our fundamental understanding of what occurs during a lighting strike on a composite aircraft structure,” he said.

“This funding will be used to improve our understanding of what occurs physically and chemically when a plane is struck by lightning to continually improve the design to be more efficient and economical.”

The PROTEST research project is a step towards safeguarding against a common hazard, but one which has rarely been identified as a primary or contributing cause of accidents.

According to a report entitled Lightning Strikes: Protection, Inspection and Repair by AERO magazine (published quarterly by Boeing Commercial Airplanes), lightning strikes are relatively common but rarely result in a significant impact to the continued safe operation of the airplane.

The report highlights that the continued problem of lightning strikes for the aerospace industry are the costly delays and service interruptions caused by the strikes, which can take an airplane out of service for an extended period of time.

For the period of January 1,1962 – April 30, 2010, the US National Transportation Safety Board  Accident/ Incident Database included 58 events in which lightning was cited as a major or contributing factor, with the 58 events resulting in 202 fatalities and 46 injuries.