LIGHTS ATA 33 Part 2

Continuing the presentation of the cockpit lighting we will continue in the order of the ATA described in the Maintenance Manual.

- Inscriptions on the flight panels and the management panels in the flight compartment are engraved on, and illuminated by, electro luminescent panels mounted on the panel assemblies.

Here are the different panels with their numerical identification.

- The circuit breakers and front breaker panels are illuminated by sets of light bars.

- The instruments, magnetic indicators and control units are illuminated by integrated bulbs.

Panel and integral lighting ATA 33-11

· Electro luminescent Panels

The panels are of a sandwich construction comprising an etched plexiglass laminate and three layers of acrylic sheets, between which are interposed electroluminescent layers of a phosphor dielectric system and two plate electrodes, acting as a capacitor.

Editor's note: We can see above the different layers updated following vandalism in the cockpit of the SA.

Electro luminescent element forming part of panels 22-122 and 24-122 on the flight engineer's console (under reconstruction) was donated to us by D.A.S. of Duxford.

When an alternating voltage is applied across the electrodes, phosphor particles form a dielectric and the resultant excitation of electrons causes an emission of light from the phosphor surface.

The lights shines through the Perspex front conducting layers and the engraving on the top laminate. The engraving is cut in a ' V ' shape, through the grey painted top surface and the white opaque perspex layer below, and penetrates, to as hallow depth, into the bottom layer of clear perspex.

This allows a line of light to be emitted at the base of the engraving.

The large panels are attached by quick release fasteners, and the small panels are attached by bolts.

On the photo above you can see the two wires that supply the electroluminescent panel marked 55LD-1 and just below the quarter-turn quick-release fastener called “dzus”

· Circuit Breaker Panels

The circuit breaker panels are illuminated by lighting bar assemblies, fitted at each row of circuit breakers.

Each assembly consist of miniature lamp holders and filaments, mounted on a printed circuit board contained in a metal channel section.

A laminated cover strip, of cobex and perspex, engraved to suit the relevant circuit breakers, is fitted on each channel section and illuminated by the filaments.

The number of lamps in each lighting bar assembly can vary, and the assemblies fitted are dependent on the length required to suit the particular panel.

Attached to the A-11 circuit breaker is this small "marker" one (tactile key) it should allow the flight engineer to find this important circuit breaker without turning around.

We put the question to Mr. Yves PINGRET who has performed 158 flights with our plane and we quote with great pleasure here his answer even if it does not give us an answer to our question.

“Concerning the circuit breakers, only those concerning the secondary flaps were identified as essential (secondary air doors) because only an action on these made it possible to switch to supersonic in the event that they remained closed. All the others identified by colours allowed me to act without looking too much but the string is not my initiative. Y.P. ”

On the left wall at the level of the observer seat just next to the panels you can see this reminder of the colour codes of the circuit breaker panels.

· Integral lighting

Integral lighting, for the illumination of instruments, magnetic indicators and control units, is achieved by the use of miniature filaments, contained within each instrument indicator and control unit.

Small 5V filaments used in announcers and 28V for lighting.