An aircraft including a longitudinal fuselage, at least two lateral wings connected symmetrically one on each side of the fuselage and at least one engine pod fixed to each lateral wing via an engine support pylon. A determining means determines that there is a failure when the contact resistance value exceeds the predetermined threshold value, and then an abnormality detection signal is outputted from an output means. A terminal block is mounted at the single, particular area. A recordingreproducing unit writes or reads, in accordance with a present sector number of a sector where the writeread head is located, a corresponding piece of sector data onto or from the DTM magnetic disk, independently of the order of the sector numbers.