The model 131, when equipped with the ADDS 1010 operator console, allows you to make limited changes to initial conditions.
The HSI heading card is adjusting using servo board potentiometers. The heading card should indicate accurately to within 3 degrees of aircraft magnetic heading.
The tachometer and manifold pressure gauge are meter movement instruments that require adjustment using trim potentiometers located on the back of the instrument.
The throttle quadrant (Models 131 and 132 only) includes throttle, propeller, and mixture controls (two each on the Model 132). Calibration is the same for all three.
This article provides instruction for calibrating the Elevator Trim for a Frasca Model 131, and a 132.
Adjust the elevator control potentiometer by loosening a setscrew on the pivot arm and turning the potentiometer shaft. Adjust the Model 135 fore/aft cyclic by loosening the setscrew on the pivot arm and turning the potentiometer shaft. The potentiometer is under the pilot’s seat.
This procedure applies only if the FTD is equipped with a dual-needle RMI but no HSI. In this configuration, a DC motor drives the RMI heading card and an AC resolver provides a feedback signal to the servo board.
Dual-Needle RMI (D/N RMI) Heading Card Calibration (D/N RMI slaved to HSI Heading Card) Model 131/132/135
This procedure applies only if the FTD is equipped with both a dual needle RMI and an HSI.
The directional gyro is a DC resolver instrument. Adjust by rotating the resolver on the backside of the instrument. Before adjusting the directional gyro feedback resolver, be sure to calibrate the input reference (phase circuitry) signals.
Adjustment of the Model 135 collective control potentiometer is accomplished by removing the collective potentiometer and mounting bracket assembly, loosening a setscrew on a gear mounted on the potentiometer shaft, and adjusting the gear position on the shaft.