Airplane lightning strikes are fairly common but can disrupt airline operations and cause costly delays. That’s why leading aircraft manufacturers like Boeing and Airbus install lighting protection on planes. Lighting diverters, a type of protection, can reduce the significance of strikes where a single bolt of lighting can contain as many as 1 million volts or 30,000+ amps. Yet that’s not all you need to know.
Understanding Airplane Lightning Strikes
Most airplane lighting strikes occur when an aircraft is flying in clouds between altitudes of 5,000 feet and 15,000 feet. Lightning strikes are also most likely during a flight’s climb or descent. According to estimates involving U.S. commercial jet aircraft, 70% of all lighting strikes occur in the presence of rain. Lighting strikes are also most common at near-freezing temperatures during spring and summer.
Lighting initially attaches to an aircraft extremity such as a radome, forward fuselage, nacelle, empennage, or wing tip. During the initial stages of a lighting strike, pilots may see a glow on the plane’s nose that’s caused by the ionization of the surrounding air. Passengers may see a glow on the plane’s wing tips instead. Regardless, lighting currents then travel along the aircraft to form an electrical circuit.
For maintenance personnel, it’s important to understand more than just when lightning is likely to occur and what a flight log may contain. Maintenance crews also need to know how to identify lightning-strike damage on a commercial aircraft. Areas that have the greatest likelihood of a direct lighting attachment need the right lightning protection, too.
Identifying Damage to Aircraft Exteriors
Lightning strikes to airplanes provide tell-tale signs at the strike’s entrance and exit points. With metal structures, maintenance personnel may notice pits, burn marks, melt-through, or small circular holes. Crews also need to look for damage around fasteners and bonding straps. The shock waves that are present during strikes can cause crushing.
Lighting strikes can damage composite structures, too. Typically, the indicators are burnt paint, damaged fiber, and composite layer removal. Whenever lightning strikes an airplane, crews need to locate the entrance and exit points. As part of this process, maintenance personnel must examine the entire structure carefully to identify all of the damage that’s occurred.
In SHINE’s next blog entry, you’ll learn more about lightning-strike inspections and repairs. You’ll also learn about WXGuard, a solution from SHINE that’s designed to keep you flying high. These multi-strike lightning diverters withstand the harsh elements of flight and are a direct replacement for your current radome lightning diverters.