Hi, all --
Re discussion of paint color, I don't disagree certain colors are to
be avoided. But I've seen many composite planes with all flavors of
lighter non-whites and metallics, and even darks on the lower
fuselage, so I looked up accident data. What I found was more
reassuring than the mere fact there's no record of any crash for such
reason, and further provides perspective on other issues discussed
here like bonding techniques, UV degradation, and composite
longevity. There are now at least 2,400 composite homebuilts flying
here, and a search of incidents for the last 25 years produces only
eleven failures of primary structure or control surfaces:
- two where a large winglet was not affixed per directions and
separated (one a kitplane)
- hull delamination on a seaplane, below the water line (kit)
- 70% of the adhesive bond area on wing spar cap was never in contact
with spar from day one [flew 178 hours like that]
- mold release wax not removed from tailplane bond area; 1/2 of
required BID tapes not applied (kit)
- composite used in a flap component where aluminum plate specified
- fuselage broke in half on a modified Quickie design, in takeoff
on a record attempt for round-the-world, unrefueled flight [no
engineering done, takeoff weight w/fuel not stated!]
- unspecified wing adhesive failure [1989 scratch-built design]
- competition aerobatic practice flight, compressive spar cap
failure due to excess waviness in the uni cloth, at 6.5 G's
- racing aircraft design, self-design, test to determine load
limits. Total breakup [largest piece recovered over a square
mile area weighed 10 pounds]
- rudder LE delamination on a gyrocopter during intentional spin
Less than half involved fatal injuries, straining belief, as the 2
cases where a chute is required here were fatals.
The data would not include failures not reported nor reportable as
accidents. Given the time period and numbers involved, the inevitable
variance in builder skills and experimentation in materials on
plans-builts, it can be assumed that any common problem would show up
in the reported cases at least a little bit. For example, the search
criteria turned up dozens of reported incidents where a fiberglass
fuel tank failed due mostly to resin incompatible with fuel used,
causing engine problems -- a failure less likely to be reported than a
structural one.
Sure looks like this construction method is a forgiving one, and none
of the most popular kitplanes are represented in the above cases.
Best,
Fred F.
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