[ARC5] standards

[Roy Morgan]

On May 14, 2014, at 4:46 AM, Sheldon Daitch <SDAITCH at bbg.gov> wrote:

> Roy,
> 
> I wonder if the right PIC convention in helicopters is due to that most people are right-handed and the cyclic is generally far more widely used than the collective, which generally is between the two pilot seats?

Sheldon,

That might be the case for helos I have not seen, but in the TH-13M (very small), the H-34 (of Korea fame) and the SH-3 (60’s 70’s anti submarine*) both seats had the cyclic between the knees, and the collective at the left thigh.

* The current presidential helicopters are basically SH-3 airframes much modified for their VIP Service.  The program to develop a new VIP helo was cancelled a few years ago.

Cyclic: controls the pitch of the blades in their trip around - allowing for tilting the rotor head for directional and speed control
Collective: controls the pitch of all blades equally, to allow for lift control: up and down.  Fine control can be had by lightly placing the thumb on the thigh to ensure good position control and tiny movements.

Sikorski’s first helicopter did not account for the 90 degree lag in the effect of change in pitch to change in lift of that blade.  So his test pilot had to quickly learn that to go forward, he had to move the cyclic to the right.  The mechanism in modern fully articulated rotor heads is quite amazing.

> That right had seat PIC would allow the PIC to use the right hand for the cyclic for the vast majority of time and the left hand for collective?  

As above, both seats are set up the same.  Often the two  pilots share the stick time pretty much equally.

Radio content:  
In the SH-3, the radios were controlled at the console between the pilots, which was two “units” wide.  The ADF, and one (or in some models two) UHF control boxes were there, along with the ICS (intercommunication system) switch panel.  Both the low frequency and the UHF radios could do direction finding.

Roy

Roy Morgan
RoyMorgan at alum.mit.edu
K1LKY Since 1958