Choppers get vibration testing gadgets

Christered Vibrax, one set of the equipment was procured earlier and was passed between Base Repair Depots and Delhi-based Communications Squadron. It was found to be highly effective and accurate.

Earlier, a conventional method as suggested by the Soviets was being used for measuring vibrations. Excessive vibrations result when the setting of different moving parts change due to constant motion.

Different colours were put on tips of rotor blades and a pole with rubber pads was held by the side of the rotor. The level of vibrations was judged by the distance between different colour marks left on the pads.

Vibrax is a portable computer-controlled machine, which measures lateral as well as longitudinal vibrations. It consists of a probe which can fit on the rotor hub, which sends inputs to the computer. It can accurately indicate the source and the level of vibrations as well as adjustments to be carried out. It displays readings of the frequency of vibrations as well the capability to give out print-outs if required.

Vibration checks are carried out on helicopters at fixed intervals or when excessive vibration levels are reported by the pilot. While, the earlier method implied hit and trial method of finding which part is causing excessive vibration, the introduction of the Vibrax will improve flight safety measures and also cut down on maintenance time.