There is no modulation available for the Bendix system installed on 250-C20 series engines. The CECO systems used on 206BII ships had this feature.
With the Bendix system, if it is going hot, all you can do is cut the throttle, and then either charge the battery, hook up an APU, or adjust the fuel control.
The Bendix fuel control has two adjustments for the start cycle on a C20. A derichment adjustment (effects temps between 0 and 30 percent N1) and the tweeker (adjusts entire start cycle).
If you are going hot at the beginning of the start cycle, you need to adjust the derichment down.
If you are stagnating around 40 to 50 percent N1, you need to go up one click on the tweeker, and turn down the start derichment.
Bendix did upgrade their systems on the 250-C28 and 250-C-30 series engines to include modulation during start cycles.
If you can get a 206BII flight manual, there will be two start procedures available for the options (Bendix vs. CECO).
Last edited by rotormatic; 26th October 2005 at 04:15.