In this lecture we will look at lightning strikes to airborne vehicles such as airplanes, space vehicles, and even briefly at Zeppelins.  We will also review a difficult recent rocket triggered lightning experiment that sought to determine the conditions necessary for a successful trigger.

As the table below shows, aircraft are "struck" by lightning about once every 3000 flight hours or about once per year.  The majority of strikes occur when the plane is inside a cloud and in precipitation.
Aircraft type
(typical cruising altitude)
 Strikes
 Flight hours
 No. hours per strike
Piston
(10,000 - 15,000 ft)
808
 2,000,000
 2475
Turbo prop
 389
 1,291,000
 3320
Jet
(~30,000 ft)
 521
 1,741,000
 3340
Combined
 1718
 5,032,000
 29130
source: Uman and Rakov (2003)

Usually the metal body of the airplane is able to safely conduct the lightning current from one end of the plane to the other without catastrophic damage.  The metal body also acts as a Faraday cage and partially shields sensitive electronics and flight control systems inside the plane from direct or indirect damage.  There are enough openings in the body of the airplane however that damage to the interior does occur.  Sparking across poorly bonded surfaces is a particular concern because it may ignite fuel.

Some catastrophic accidents have occurred of course.  A few are summarized below.

Saying that aircraft are struck by lightning may be misleading because in perhaps 90% of cases it is the airplane itself that initiates or triggers the lightning discharge. 
In this first one a Boeing 747 is struck shortly after take off from Komatsu Airport in Japan in the winter.

Note the clear branching that points away from the two extremities of the airplane, evidence that the discharge began at and moved away from the plane ( here's a video of the discharge).

A Qantas L-1011 struck on Sept. 5, 2004 (this video I think) during its descent into the Sydney airport.

On April 23, 2011 an Emirates Airlines Airbus A380 was struck during final descent to London Heathrow (source of the still photograph below)

Here's a video (from the Washington Post article) where you can see the lightning channel sweep along the fuselage.  Here's a pretty good written description from the videographer himself.

In the unusual cases where the airplane intercept a natural lightning the plane is near the ground.  This video seems to be one of those situations.

Uman and Rakov (2003) and Uman (2008) discuss four research programs in which instrumented aircraft were purposely flown into thunderstorms in order to better determine the conditions that could lead to lightning trigger.


1964-1966
US Air Force Cambridge Research Laboratories
"Rough Rider Project"
used an F-100F aircraft
 (a 2 seat trainer version of the F-100, I believe)
studied thunderstorms in Florida

current recording system may not have had sufficiently fast time response to accurately determine
current rise time and peak dI/dt values


Four US Air Force North American F-100C Super Sabre jets 
flying in formation
(source of this image)




1980 - 1986
NASA Storm Hazards Program
used a NASA  F-106B aircraft

About 1500 thunderstorm penetrations at altitudes ranging from 5000 to 40,000 ft.  Struck by lightning 714 times.  Almost 10 times as many strikes were recorded at high altitudes than at lower altitudes even though the numbers of penetrations at the different altitudes were about equal.
A US Air Force F-106B Delta Dart
This is a two-seat trainer version of the aircraft
operated by the New Jersey Air National Guard
source of this image





1984, 1985, and 1987
USAF/FAA Lightning Characterization Program
used a Convair - 580 twin engine turbo prop aircraft
A Pionair CV -580 aircraft (Pionair is a New Zealand based airline)
source of this image





1984 and 1988
no data apparently from the 1984 experiment
the 1988 experiment was conducted in the south of France

A particular interest were the processes that occur at the beginning of lightning discharges triggered by the aircraft.
A Transall C-160D transport aircraft
operated by the German Air Force.
The Transall is built by a consortium of French and German companies.
source of this image











References:
Uman, M. A. and V. A. Rakov, "The interaction of lightning with airborne vehicles," Progress in Aerospace Sciences, 39, 61-81, 2003.

Laroche, P., P. Blanchet, A. Delannoy, F. Issac, "Experimental Studies of Lightning Strikes to Aircraft," Journal Aerospace Lab, Issue 5, December 2012 (available at
http://www.aerospacelab-journal.org/sites/www.aerospacelab-journal.org/files/AL05-06_0.pdf)

Washington Post article on lightning strikes with details about Qantas strike and emirates A380 strike.
available at: http://www.washingtonpost.com/blogs/capital-weather-gang/post/airline-safety-is-the-fear-of-a-lightning-strike-warranted/2011/05/17/AFD2vs5G_blog.html