An Eyepiece-support arm assembly device on an aircraft. The walls are joined to one another at each corner of two adjacent walls by providing a mounting tab foldable relative to one of the wall and a tongue on the other wall to receive and retain the mounting tab by interlocking connection of mating connections. The proportion of cordierite crystal having solid-dissolved therein W and Ti is 25 mol % or more, whereby a high-performance directly supporting ceramic support is realized. Each of the probes includes a sensor generating signals corresponding to target passing events, and a set of synchronous harmonics of the rotational speed of the rotor are produced for each sensor. All bias current circuits may be identical in a linear interpolator. When a total of a thickness of the first wiring line layer and a thickness of the second insulating layer on the first wiring line layer is T1 and a thickness of the second insulating layer at a position where a surface of the second insulating layer is flat and which is away from the first wiring line layer by a predetermined distance is T2, T1\u2212T2<4.