4-in. Training Flare Mks I, III, IV, VII, and VIII, and 4-in. Reconnaissance Flare A.S., Mks I and II (Service)

Description: The 4-in. Training Flare Body Mk IV comprises a front body portion con-taining a flare candle and a pull percussion igniter, and a rear body portion containing an 11-ft. cotton parachute, which is connected with the candle unit. The front and rear body portions are connected by a diaphragm, which closes one end of the front body and supports the flare candle and igniter. Two suspension bolts on the diaphragm provide an anchorage for the parachute. The opposite end of the front body is closed by a mill-board disc held in place by a fusible closing disc. In addition to the igniter plug, the igni-ter comprises an igniter body, which houses a striker mechanism, and into which the ig-niter plug is screwed. The igniter body is held in place in the central tube by a retaining plate.

The A.S. Reconnaissance Flare is identical to the Training Flare except for a delay fuze below the igniter, which gives about a 5-second delay before burning starts.

Functioning: When the flare is released, the long static cord, the free end of which has been attached to the rear crutch holder of the carrier or to the eyebolt on the lid of the launching chute, is withdrawn from the elastic loop and pulls the retaining pin out of the loop on one of the flaps, thus releasing all flaps. The flare falls, with the parachute being drawn out of the body because of the connection between the short static cord and the long cord attached to the plane. Tautening of the auxiliary static cord breaks teh thin braided cord, separating the flare from the cord attached to the plane.

After the chute has opened, the body of the flare continues momentarily to fall freely until the suspension rope is fully tensioned. The jerk as the suspension rope tightens causes the securing wire to bent and the clutch to be pulled out, spring-loading and re-leasing the striker. The striker, when released, moves downwards and fires the percus-sion cap. This flash ignites the gunpowder in the training flare, sending a flash down the center tube by the primed cambric tube, igniting the burster charge. (A percussion cap ignites the safety fuse in the A.S. flare.) The flash from the burster charge passes through the holes in the apertured washer and ignites the primed cambric washer and the priming composition at the bottom of the flare candle. The priming composition igni-tes the flare composition, being assisted by the six portions of igniter composition which ensure a substantially even ignition of the flare composition. The fusible closing disc at the nose of the flare melts and permits the candle to burn freely.

Suspension: The flare has a suspension band to which the lug is attached.

Remarks: The 4-in. Training Flare Mk I has a silk parachute, and a safety pin held by a split pin instead of a securing wire. The flash from the gunpowder is conveyed to the burster charge by a length of instantaneous fuze instead of by a primed cambric tube as in the Flare Mk IV. The 4-in. Training Flare Mk III has a silk parachute, but it is a stron-ger one than is used in the Flare Mk I. The 4-in. Training Flare Mk VIII has a slightly dif-ferent cotton parachute than the Flare Mk IV. The 4-in. Traning Flare Mk VIII has an ig-niter fitted with a copper shear wire, which passes through holes near the top of the ig-niter body and in the clutch. The shear wire is fitted to assist assembly during manufac-ture. It is broken by the jerk which bends the securing wire and pulls out the clutch. The parachute is similar to that of the Mk VII.

The 4-in. A.S. Reconnaissance Flare Mk II has the same changes as 4-in. Training Flare Mk VIII.

These flares are used primarily for training purposes, and, after being dropped from an aircraft, are supported by their parachutes even if they are not ignited. The flares can also be used to assist in making an emergency landing during night flying.

Figure 83 – 4-in. Training Flare Mk IV