FlyCRJ.com

Well, it happened yesterday. We were struck by lightning during the last ten minutes of our flight while descending into SFO.

We could hardly avoid it. We weren’t painting anything on our radar but ATC saw that we were headed towards an area of heavy precipitation so he vectored us away from it. But, by then, it was too late. A few seconds after we made the turn…BAM!…lightning struck. Didn’t see it as much as we heard it!

It was super loud but the airplane didn’t even budge. All our electronics stayed online, including our radios, and we continued to the airport in a torrential downpour and a huge headwind. It was an exciting couple minutes.

Side note: It always amazes me…the whole flight can be boring…but the last ten minutes can be very exciting. I wrote another article, Two Hours of Sitting, 20 Minutes of Work, that talks about the last couple minutes of a flight and how they can be the most interesting. Check it out!

But if you are looking for more interesting writing, here are some books recommendations on weather flying:

Weather Flying – Robert Buck’s Weather Flying is regarded in the industry as the bible of weather flying.
Severe Weather Flying – Describes how to anticipate hazardous weather conditions, avoid them in flight, and get out of them when encountered.
Bushnell FX5 Weather Station – 5 Day Forecast- Featuring reliable, real-time weather forecasts for over 150 cities provided by the most accurate weather service, AccuWeather.

Anyway, once we got to the gate and all our chores were done, I went for a look of the exterior. It turns out the radome was scorched and the inside had been blown off. The nose wheel doors took the brunt of it and were scorched really bad. And as lightning does, it took the path of least resistance, traveled along the airplane, and exited the airplane on the left horizontal stabilizer taking the static wick off with it and bending the metal. More on static wicks in a minute.

Obviously, the next flight for that airplane was cancelled…the airplane was ferried to SLC for maintenance and it should be back online in less than 24 hours.

And that was just the first flight of the day!

So What Happens When Lightning Strikes an Airplane?

When an airplane is struck by lightning, the nose typically takes the hit. In my three lightning strikes, the initial impact has been on the nose area. The exit point is usually somewhere else on the airplane like the wing or tail.

The skin of an airplane, which is mostly aluminum, is a great conductor of electricity and allows the current of the lightning strike to flow through the skin to its exit point, without interruption or re-routing through the interior of the airplane, thus protecting its internals. There is a law that discusses this phenomenon of electric flow called Gauss’s Law for all you brainiacs!

So How Does Lightning Form?

In its simplest form, lightning is really two sets of a massive amount of electrons seeking equilibrium. As the electric charge builds, they move until they find another huge electrical charge, then BAM, they connect and release all their energy, which is lightning.

Typically, there are two types of lightning: cloud-to-cloud and cloud-to-ground. In the case of cloud-to-cloud, two highly charged portions of cloud eventually connect and form lightning. However, an airplane can sometimes act as what they call a “step ladder” and connect the two highly charged particles and you get your BOOM! Why trees get struck by lightning so often is because electricity builds on the tree, moving up, and meets with the cloud electricity which is moving down. In this case, the tree has acted as the “step ladder.” 

How Static Wicks Protect Airplanes

CRJ Static Wicks and Horizontal Stablizer End Caps

Static wicks are small pieces of metal connected to the frame of the airplane on the tail and wings. Their purpose is to dissipated these “step ladders” by concentrating the electric charge around them. The build up of electricity is then safely dissipated into the surrounding air. Furthermore, if lightning does hit the airplane, it will hopefully travel through the static wick and not the airplane. This helps protect the airplane. In our case, this is exactly what happened as the electricity found its way through the airplane and blew off the static wick on the tail.

CRJ Lightning Protection Enhancements

Now to me, it seems that the CRJ200 seems very susceptible to lightning strikes more so than other airplanes because of its sharp and pointed design. To partially help combat this, static wicks have been added to the airplane to help protect the airplane. A metal shank kit modifications have also been added and put of the winglets and the horizontal stabilizer, which are designed to intercept a lightning strike, divert the energy to the metal shank, confining the damage to the metal shank itself, and thereby minimizing damage to the aircraft.

Obviously, the airplane, even with these modifications, are susceptible to lightning strikes regardless of these modifications. I found out later that four of our airplanes had been hit on this day alone. Ours was the worst.

So, just to recap, airplanes are typically very resilient to lightning strikes and can handle them very well. I would rather not get hit by lightning simply because it cost money to fix and usually inconveniences and frightens the passengers, but if and when it does happen, it is good to know that me, my crew, my airplane, and my passengers are safe.

Till next time…to your flying success…

Jeffrey

P.S. Here is a terrific site on How Lightning Works.