embodiments a brace 76 extends across the flared portion 22 to support one end of the biasing member the brace 76 may be embodied as two members positioned cross wise having the ends thereof secured to the flared portion 22 referring to fig1 a method 48 for using the apparatus 10 of fig1 a 12 b and 10 may further include disengaging the latching mechanism 72 and extending 78 the outer cone 70 the method 44 may include expanding 78 the horn 12 such as by disengaging the latching mechanism 72 only upon sensing 64 contact of the apparatus 10 with the ground in some embodiments sensing 64 may include breakage of the latching mechanism 72 due to the force of impact in order to permit extension of the outer cone 70 for example the latching mechanism 72 may be embodied as a post or filament extending between the inner and outer cones 68 70 that is broken by relative movement of the inner and outer cones 68 70 that occurs upon impact referring to fig1 a and 14b in one embodiment change in the size of the horn 12 is accomplished by expanding the flared portion 22 the biasing member 72 extends across the flared portion 22 such that it urges the flared portion.