TYPE C.2780


Stores Ref. No.:5CZ/7134 | 5CZ/1089998
Manufacturer:Page Engineering
Manufacturer P/N:C.2780
Attachment:28D/1010658 | A25/1B | Bolt, 4BA, hex head | Qty: 4
Attachment:28W/9419401 | SP10/B | Washer, 4BA, plain | Qty: 4
Connection:UK-AN / MIL-C-5015, 28-21P, 37 way
System:Warning and Emergency Services


This unit forms an important part of the functionality of the standard warning system. In essence it is a hardwired logic control unit that provides some functions associated with warnings based on aircraft sensors/switches.

When a hazardous condition arises, a switch contact in the airframe closes, illuminating a pair of lamps in one of the warning panel caption windows. This warning could be a high/low pressure, temperature, an electrical issue, or other hazardous condition. The warning system observes conditions of many other systems.

The flasher and excitation unit only interfaces to the standard warning panel (SWP), which annunciates the warnings classed as critical. It electrically monitors the power to the warning caption lamps, and upon illumination, the flasher and excitation unit is responsible for flashing the attention getter lamps, and sounding the audio warning alarm. It latches in this state until the SWP "C" cancel button is pressed, or the warning clears naturally.

An SWP muting function is also provided for ground use, as during prolonged periods of servicing or systems testing the SWP lamps may overheat. This is carried out by the flasher and excitation unit by removing the earth connection to all SWP lamps apart from the fire warning lamps, which are permanently active. A further benefit of the SWP muting function is to mute the audio warning alarm, meaning the intercom can be used by ground crew / technicians working on the aircraft with no nuisance audio alarm.

Flasher & Excitation Unit

Flasher & Excitation Unit


In the T Mk.5 & T Mk.55 Lightnings, this unit is located behind the port (pupil) ejection seat.

BAC 55 (SA-3) T55 IPC, Book 1, Section E, Fig 14
Alarm unit marked - item 20 or 21

Shown below on the cockpit sloping rear bulkhead, next to terminal block T.B. C13, its connector just behind the port ejection seat main rails.

Flasher and Excitation unit installed in
XS458, cockpit rear bulkhead, port side, 07/10/2018


The flasher and excitation unit is responsible for the following functions: