Most common types have suffered in flight breakups. A few (very few) types haven't. The Socatas have a single piece aluminium spar, machined from a solid lump.
Well how does the Grumman AA5 fair up in this debate. No none in flight structure failures.
How does 15G sound. Quote from a recent forum question on the Grumman Gang
Except for the Grumman, most wing structures rely on a forward and rear "I"
beam spar with both spars interconnected to the fuselage structure and then
relying on the skin of the wing to keep the spars perpendicular to the air
loads. The sheet metal "I" beam looses it's strength if twisted slightly.
The main reason so many strutless Cessna 210s have lost wings is the skin
wrinkles between the spars twisting the rear spar causing it to fail.
Grumman's rely on a massive tube that can withstand loads equally in ALL
DIRECTIONS. There is a rear spar but it ends at the wing root and is not
attached to the fuselage, therefore all flight and accident loads are
transmitted into the center spar without reliance on skin structure. Air
loads go from the skin, to ribs, to spar collars, to one spar, to fuselage,
similar to some rag wing airplanes.
Hypothetically if you were to saw a Grumman wing in 1/2 at the root without
touching the center spar it would have almost the same strength as before.
Can't do that to any of the brand X without the wing flexing all over.
Remove a Piper leading edge fuel tank and that wing becomes very flexible.
Disadvantages of a tube spar are that it theoretically doesn't give a much
strength per pound of aluminum.
Advantages are it will withstand G loads with or without twisting loads,
incredibly hard impacts with hangers, tugs, etc. without buckling the rear
spar as with other aircraft. Damage is usually limited to the skins.
Exceeding the "G" limits will buckle or compress the upper spar surfaces and
stretch the lower surfaces. So far those "Gs" have been less then 15 or so
in flight. I have seen an extra 12" dihedral in the wings and anhedral in
the horizontal stabilizer "15G" load according to Gulfstream Aerospace. I
have two buckled outboard wing panels here that withstood a loaded DC-10
wake turbulence that was so violent it sheared both 1/2" chrome molly steel
aileron counterweight tubes and sent them into an apartment building below.
Both airplanes continued flight without incident.
The above aircraft was not totaled.
Except the wings, the airplane was fine, I trailered it back to Houston from
LA and we inspected the entire airplane especially the spar attach points
and spar, found no damage. We installed a pair of new wings and flew it
back.
David Fletcher
The 15G load incident was not the same as the DC10 wake turbulence incident. Believe that one was an encounter with being sucked up inside a CB and spat out. Wings, spar, horizontal stab and windows had to be replaced in that one, but it did survive. The 15G was what Gulfstream said the spar had been stressed to after putting it though their test rig.