Yokes — Articles / Posts — Flaps 2 Approach

I thought it time to post what’s happening with regard to the construction of the simulator. Additions and improvements are in the pipeline and it’s hoped that OEM control columns and a new platform will be installed very shortly.

Currently the simulator is mounted on a fiber-board and wood platform, which I constructed when I received my Main Instrument Panel (MIP) just before Christmas 2010. The platform has served me very well and was perfect for the installation of the ACE yoke and Precision Flight Controls (PFC) rudder pedals.

Soon after constructing the platform and purchasing the ACE yoke, I was able to secure two OEM B737-500 control columns. I was surprised to find these units so quickly and I was fortunate that my timing coincided with the dismantling of a late model B737-500.

Fitting the OEM control columns to the wooden platform appeared to be problematic, as the platform was a tad low in height and it was awkward to retrofit the linking rod that connects the control columns for duel operation. Therefore, I decided that a new platform was required; custom designed to fit the control columns.

Aluminium Modular Design

Rather than use wood and fiber-board, I selected aluminium tubing cut appropriately and TIG welded together. To facilitate future transport, the platform has been constructed in modular form. The forward portion comprises three modules bolted together in strategic places, while the rear part of the platform (not shown), where the seats and center pedestal reside, abuts snugly to the forward section. It’s intended to use high density ¼ inch plastic/vinyl as the upper cover on the platform as this material is easier to work than aluminium sheeting, is light in weight, very strong and comes from the factory in Boeing grey.

In the photographs (click to enlarge) you can see the control columns (striped completely) fitted to the forward modular section of the platform. The control columns are connected to each other by a ¾ inch heavy duty shaft and heavy-duty double bearings. Forward and aft movement of the control column is controlled by a heavy duty spring and left and right roll movement is controlled by another spring.

Control Column Pull Pressures

The pull pressure on the control column is set to 24 pound which is slightly less that the standard pull in the B737 which is 34 pound. The pull can be easily altered by moving the spring forward or backward on the spring retainer. The pressure on the roll component is presently 12 pounds. I've been told the roll pressure as per the Boeing maintenance manual is +_15 pound; therefore, I'm well within the ball park.