The INSCO 6520 series are concentric three-pointer magnetic drag
tachometers produced for the twin helicopter market. They provide
reliable speed indication for both engines and the main rotor.
Qualified to TSO C49a, they can be supplied with dial configurations
for Bell 212, 214 and MBB BO-105 series.
This updated tachometer is driven directly from the engine-mounted 2
pole tach generators, and requires no external power (except for
integral lighting). In the event of instrument bus shutdown, the
6520 will continue to function. Designed for years of trouble-free
service as an OEM or replacement tachometer.
sources: (3) 2-pole tachometer generators, GEU-7A or Equiv.
Accuracy: + / - 1.5% F.S. (for better accuracy, consult factory)
Temp Drift: Less than + / - 0.5% F.S.
Power Requirements: None
+ / - 1% F.S. Max.