All airplanes are equipped with modern lightning protection systems, yet incidents of lightning strikes still occur.
All Airplanes Have Lightning Protection Systems
According to Professor Nguyen Duc Cuong from the Vietnam Aerospace Association, all aircraft are equipped with lightning protection systems to ensure flight safety in turbulent areas. The aircraft’s metal fuselage can conduct electricity, so this lightning protection system must be connected to distribute any electrical current, such as that from a lightning strike, evenly across the aircraft’s body and direct it to the lightning protection system.
While flying, airplanes generate significant friction, which leads to the presence of discharge rods during flight. The aircraft’s lightning protection system also operates on this principle, ensuring that the aircraft avoids being struck by lightning during flight.
Holes on an airplane from lightning strikes.
When an airplane is on the ground, the lightning protection system remains active. At this time, grounding wires must be in place to ensure the aircraft’s safety. If a lightning strike occurs, it may be due to issues during maintenance or operation when grounding is not considered.
Professor Nguyen Duc Cuong noted that since all aircraft have lightning protection systems, current regulations do not require airports to also be equipped with lightning protection systems.
How Do Airplanes Get Struck by Lightning?
In 1963, lightning caused an accident involving a Boeing 707 of Pan American in Maryland, USA. The incident resulted in the deaths of 81 passengers on board. At that time, the crew lost control of the aircraft after being struck by lightning.
Typically, airplanes are struck by lightning at altitudes between 5,000 and 15,000 feet (1,524 to 4,572 meters), usually shortly after takeoff or landing. The presence of rain increases the likelihood of lightning strikes.
If lightning strikes after takeoff, the aircraft usually returns to the departure point. This precaution is mainly to ensure that all systems are functioning properly, as some systems cannot be restarted mid-flight.
Most lightning incidents occur during spring and summer. The probability of lightning strikes typically decreases when the aircraft is at altitudes above 20,000 feet (6,096 meters).
A lightning strike can be quite an uncomfortable experience for both the crew and passengers on the aircraft. However, in most cases, it does not cause significant physical damage to the aircraft and does not affect safety.
Typically, lightning strikes specific parts of the aircraft, such as the wingtips or nose. The electrical charge then travels through the aircraft’s metal shell before reaching another point, such as the tail. The sound of lightning can be nearly deafening in the cabin, although the crew might not hear anything at all.
The type and extent of damage caused by lightning strikes on an aircraft depend on several factors, including the intensity of the discharge, the location, and duration. A single lightning bolt can carry about 1 million volts or 30,000 amps.
Lightning can cause minor effects on the atmosphere, compass, avionics, and leave small holes on the fuselage, winglets, and tail. Additionally, lightning, especially at night, can temporarily blind the crew.
In more severe cases, incidents can lead to engine shutdowns. In rare cases following a lightning strike, one or more generators may shut down. This can turn off cabin lights until the generator is restarted.
Lightning strikes can impact airline operations, leading to costly delays and service disruptions. To avoid such incidents, maintenance personnel must be well-versed in lightning protection measures and adhere to proper inspection and repair procedures.
The standard procedure for pilots is to stay at least 20 nautical miles away from any Cumulonimbus (Cb) clouds. Furthermore, modern aircraft are designed to allow lightning to travel along the fuselage without causing harm.
