Sec. 25.723 - Shock absorption tests.
(a) The analytical representation of the
landing gear dynamic characteristics that is used in determining the
landing loads must be validated by energy absorption tests. A range of
tests must be conducted to ensure that the analytical representation is
valid for the design conditions specified in §25.473.
(1) The configurations subjected to
energy absorption tests at limit design conditions must include at least
the design landing weight or the design takeoff weight, whichever produces
the greater value of landing impact energy.
(2) The test attitude of the landing
gear unit and the application of appropriate drag loads during the test
must simulate the airplane landing conditions in a manner consistent with
the development of rational or conservative limit loads.
(b) The landing gear may not fail in a
test, demonstrating its reserve energy absorption capacity, simulating a
descent velocity of 12 f.p.s. at design landing weight, assuming airplane
lift not greater than airplane weight acting during the landing impact.
(c) In lieu of the tests prescribed in
this section, changes in previously approved design weights and minor
changes in design may be substantiated by analyses based on previous tests
conducted on the same basic landing gear system that has similar energy
[Doc. No. 1999-5835, 66 FR 27394, May 16, 2001]