of the cone bolt 1 where it engages the female thread on the top portion of the cone bolt 1 additionally as shown in fig2 the apu attachment bracket 51 52 of said main mount 41 is divided into at least two parts a first part 51 wrapping a first longitudinal portion of the cone bolt 1 and connected to the auxiliary power unit 30 and a second part 52 wrapping a second longitudinal portion of the cone bolt 1 and connected to the auxiliary power unit 30 it has the advantage that in case one of the two parts 51 52 breaks the other part will still support the main mount 41 up to limit loads and the system is also additionally fail safe regarding the apu attachment brackets 51 52 furthermore the elastomeric element filles the void between the part of the cone bolt 1 in connection with the housing 6 and the housing 6 itself since the system may forego any of the interfacing points except the main mount 41 and the main vibration isolator is inherently fail safe the apu suspension system of the embodiment shown in the figures is a fully fail safe system with regards to both a strut 10.