A growing new class of kit-built composite aircraft also raises some
concerns. Because owner-assembled, kit-built aircraft are considered
by the FAA to be "experimental", they are not subject to lightning
protection regulations. Many kit-built planes are made of fiberglass
or graphite-reinforced composites. At Lightning Technologie's
laboratory, we routinely test protected fiberglass and composite
panels with simulated lightning currents. The results of these tests
show that lightning can damage inadequately  protected composites.
Pilots of unprotected fiberglass or composite aircraft should not
fly anywhere near a lightning storm or in other types of clouds,
because  non-thunderstorm clouds may contain sufficient electric
charge to produce lightning.  NASA has a Small Business Innovation
Research project for the development of cost-effective lightning
protection for kit-built aircraft. Conducted by Stoddard-Hamilton
Aircraft, Inc. and Lightning Technologies, Inc., the program
designed and tested lightning protection against severe in-flight
strikes for Stoddard Hamilton's fiberglass composite Glasair III LP,
a small high-performance, kit-built aircraft.