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NOTES 1. S=Airplane normal nose rib spacing for the chosen critical station 2. Each nose rib same as the chosen most critical one 3. For some designs shot bag loading of lower surface only will be acceptable
3. Fabric covering.–When the unit tested is a fabric covered
surface, the fabric should be installed as for service except that only the primer coats of dope should be applied, in order to leave the covering slack. The load should be applied directly to the covering. The final coats of dope can be applied subsequent to the tests.
Figure 2–IX. Test assembly for leading edge having alternate nose ribs and nose formers.
4. Brace wires. During the test all brace wires must be rigged
so that they are at least as tight as they would ordinarily be in service. If any wires become slack during the test, that fact should be noted in the report and a statement given
concerning the approximate load at which it occurred. 5. Load application.—The test load can usually best be applied
by means of bags of sand or lead shot, so distributed as to
represent the required loading. 6. In the case of a test for the so-called "balancing" condition,
it should be noted that all the load acts in one direction on
the fixed surface. C. Test report.-In all cases the manufacturer making a test is
required to submit a complete report covering details of tests. The report should include photographs or drawings of the test setup and the test specimen; photographs of failed parts or sections; records of deflections and readings taken; date of test;
Figure 2-X. Typical setup for test of a box type wing beam and its attachment to the fuselage.
Single jack to apply all of the
TYPICAL SET UP FOR TEST OF A BOX TYPE WING