Originally Posted by
212man
I’ve not flown the 139, but other automated types I have will keep the heading very accurately if you keep your feet off the pedal micro switches, and typically do so even with some bank applied below a certain IAS, above which they revert to coordinated turn mode. It’s not even a function of the automation - it’s a fairly basic ATT mode AFCS function.
Hi 212,
You are correct with the 139 as well. The aircraft uses yaw to maintain heading below 40 knots and roll to maintain heading above. It will maintain a coordinated turn no problems at those higher speeds. The aircraft will also maintain its heading in the hover very accurately with your feet off the pedals and on the floor.
The micro switches are very sensitive in the AW139 and the pedals lack the outer “horns” several other aircraft utilize to rest your feet on keeping them off these micro switches. The only option left in the AW139 is the floor where the majority of the pilots I’ve flown with place their feet while flying on instruments or VFR, coupled or uncoupled at speeds above 40 knots.
However, during a helipad or helideck departure I have yet to see a single person take their feet off the pedals and place them on the floor. Deck edge turbulence and collective power changes are just a few of the things that could require the input of pedal at yaw rates greater than the automation can provide.
There is also the requirement to be hands on and flying attentively during the hover and initial departure which I believe doesn’t include placing your feet on the floor as you rotate.