Installed in my cockpit at an angle of 30 degrees, slightly in front and above the pilot’s head, this panel contains only a small number of the original Boeing 737 Overhead Panel’s elements.Because of space constrains I had to relocate the remaining parts of the original to lateral panels left and right of the pilot. The process of fitting a 737 Overhead Panel into the confines of an F-16 cockpit is documented on the B737 OHP Overview page.
This panel contains the following subsystems and switches:
Like all V.3 panels, the OHP is built from two layers. The first one is a support layer, cut from black Acrylic glass. The second layer consists of individual sub-panels made from transparent Acrylic, allowing for backlighting.
The black support layer is painted grey like the rest of the cockpit’s interior. With all switches and dials installed, the panel already looks like the finished product. But it took almost a year before this panel became fully functional.
All labels are visible from behind, through the transparent acrylic glass of the 2nd layer.
A shot taken during the early stage of canopy re-design. The big opening in the center is for the OHP. The opening on the left will eventually contain the cabin pressure control panel. On the left I might install the Boeing 737 clock. Not that I really need it, but it would look very cool up there!
Trial installation of the OHP in the wooden canopy structure.
Backlighting this panel was a challange, because the distance between panel and outer canopy skin is only 35mm. A thicker body was not an option. Had this part of the canopy been any taller, it would have cast a shaddow on the projection screen.
A low panel height is not impossible to achieve; it just requires a bit of advance planing. The biggest challenge was to find suitable wide angle LED that could be installed closer to the panel.
There is a total of 12 digits in the display window of the OHP-Top panel. They show AC and DC voltage, amps and frequency.
For the first time in years I had to go back to the almost forgotten art of wiring 7-segment displays.
At this stage, all switches, digits and LEDs are wired. Even though this is not the largest panel in my cockpit by dimensions, it is the most densely packed. The cable harness that comes out on the side of the panel is almost 2 cm in diameter.
Since there are so many backlit labels, special attention had to be payed to the routing of cables. Stray cables can cast visible shadows or obscure a label when the backlighting is switched on.
Because of the sheer number of elements in this panel, I used lots of handwritten references to avoid getting lost. Frequent testing and the use of a multimeter are a must.
The OPH after installation.
I am very pleased with the result: Once the canopy is closed, the panel is in an ergonomically correct position. It is easy to reach without being in the way, and it can be scanned at a glance during flight. Some of the protective switch covers prodtrude into the outside field of view, adding to the feeling of being “surrounded” by cockpit elements.
The canopy of my cockpit can easyly be removed for maintenance. Because of this, a solution was required for quick disconnection of the OHP cables.
The idea I came up with is shown here: a small box, velcroed to the outside of the fiberglass shell. It contains five sockets where the 20-lead flat ribbon cables from the OHP are plugged in. Further distribution and harnessing of the cables happens inside the cockpit’s body.
Even though the canopy has a double shell, routing the cables through the hollow inside would have been a major complication. I opted for a simple cable channel that runs along the outside of the canopy. The channel is fixed to the canopy with only two screws and can easily be removed in case the OHP needs to be serviced.