MIL-DTL-27443F (USAF)
4.5.8.4 Salt fog test. The pallet shall be subjected to salt fog in accordance with Procedure I
guidelines, Method 509.4, of MIL-STD-810. Duration of exposure shall be 24 hours. Test shall be
repeated for 4 cycles (see 3.4.7).
4.5.9 Destruction analysis. Each test sample shall be cut up and tested for bond, shear tie, and
penetration. Care shall be used in cutting the test samples for analysis so that excess heat is not induced
into the adhesion line. All parts of the pallet shall be permanently identified. The tests shall be as
follows:
a. Each rail shall be cut from the pallet so that 6 inches of the sandwich structure is still intact. From
each rail section, 4 each 1 inch samples shall be prepared, 1 from each end and 2 from the center,
for lap joint tensile shear tests between the skin and rail sections. MMM-A-132 shall be used as a
guide in preparing and performing lap joint tensile shear tests. The test specimens shall meet the
requirements of MMM-A-132 test number 1. The remainder of the sandwich construction shall be
cut into 8 equal (approximately) pieces (see 3.4.8 a.).
b. One test specimen 4 x 9 inches shall be cut from each quadrant of the pallet. These samples
shall be subjected to the peel test (see 4.5.10).
c. Using a 1 inch square steel mandrel, apply a 900-pound load to the top surface of one test
panel. At the option of the supplier, the corners of the mandrel may be slightly rounded. The test
panel may be from either test pallet number 1 or 2. The test specimen shall withstand the 900-
pound load. Permanent deformation of the test panel in the load area shall not exceed 0.005 inch in
depth. Deflection while under load shall not exceed 0.015 inch.
d. After cutting the pallet (see 4.5.9.a) inspect the shear-tie bond between the core and rail and the
core modules. Any gap (lack of shear-tie bond) between the core and side rail, or between the
core modules that exceeds 0.020 inches in width and 4 inches in length (along the bond line) shall be
cause for rejection.
4.5.10 Peel test. After curing, each specimen shall be peeled top and bottom and the metal-to-wood
joints on the peeled specimens inspected. An acceptable metal-to-wood joint shall consist of not less
than 100% wood failure. Local areas of high density wood (growth rings) shall be exempt from this
requirement providing the high density wood is randomly scattered and does not exceed 3% of the
surface area. Core block glue lines are not considered as wood. After 1000 consecutive samples are
tested without a failure, the peel test shall be reduced to one test specimen per shift.
4.5.11 Shear-tie inspection. The shear-tie-bond line, between the core and side rails, shall be
inspected prior to assembling the top skin. Nonconformance to (see 3.3.2) shall be cause for rejection.
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