Aircraft-engine torque instruments

J. A. Townsend (engineering division, Wright Field, Dayton, Ohio): The electric torque instrument of whatever type appears to be at a disadvantage in its present state of development, because of inherent installation, calibration, and maintenance difficulties, at least for use on production airplanes. While the hydraulic torque instrument is also susceptible to improvements, particularly in low-temperature operation and in overcoming torsional vibration with resulting erratic indications of the pointer, continued development would appear to have more promise of success than with an electric type.