Anyone with 212 AFSC/SCAS experience??
 

Just working through a scas problem, but found out that you are supposed to take the scas yaw channel off also, if you loose #1 hyds never heard of it before today, so a heads up for those with scas

lamanted,

It's in the Flight Manual: Section 4, AFCS/Autopilots:

Hydraulic Failure - System No. 1

Disengage yaw channel by turning yaw select switch OFF.

Hydraulic Failure - System No. 2

Disengage pitch and roll channels by turning pitch and roll select switches OFF.

The SCAS actuators are hydraulic. System one powers the yaw axis system two powers pitch and roll. Failure of one hydraulic system results in the loss of SCAS in the affected axis.

Also check up on whether the tail rotor assist function is installed....hydraulics off will find you pushing the pedals a bit different than you would expect as the collective and yaw pedals will move in concert with the hydraulics off. When SCAS is working as advertised it is much more pilot friendly than the Sperry with just the Heli-pilot boxes and no Flight Director.

My SCAS in a 212 brings back a lot of memories . . .

My first job ever was as a copilot in a 212 with SCAS, I had 38 hours of helicopter time, and when I flew the SCAS ship I hovered and flew like I had thousands of hours!

Then one day the SCAS became inop, and I have been trying to hover like I did back then ever since :ugh:

it was odd that a all the guys at work didn't know that you needed to haul the scas offline, but a Bell test pilot in recurrent training found our servo not working in hyd off.

Sperry 3 axis autopilot
 

Sorting out our new ( to us ) 212 with a sperry system in it. Pilots ( also new to the system ) have reported a couple of problems. During training with heli pilot 1 "on" and either in SAS or Att, and with #1 hyd system failed, there seems to be feedback in T/R, almost like pedals are "hunting". Switch off auto pilot and problem goes away instantley. I have not yet found anywhere in the FM where it says to shut off autopilot if you have a hydraulic failure. Is this standard practise? Do we even have a problem?:ugh:

It's been a long time since I worked on one, here are a couple of thoughts.

1. Check the t/r pedal minimum friction as the AFCS actuators push against that in order to move the servo valve. If it is loose then you'll feel the actuator movement in the pedals.

2. Since #1 hyd is off, the tail rotor is now unboosted and the yaw actuator can't move the servo so it's feedback may be felt in the pedals.


Chuck

I think that is what was happening. The actuator was now trying to "push" the whole T/R system instead of just the pilot valve. Turns out that the Sperry supplement in the flight manual was missing part of one page. Just so happened to be the page that states. "With #1 Hyd system failure, switch off helipilot #1" Pretty much solves my problem....