4.5-in. Skymarker Flare No. 1 Mks I, II, and III (Service)

Description: The flare has a tubular body containing the candle unit and the Para-chute Mk V. The tail end of the body is closed by a closing dome, and has four tail fins attached. The nose end of the body is closed by a diaphragm to which a bush is secur-ed. The transit plug or the nose fuze is screwed into this bush.

A flash hole in the diaphragm is covered by a paper disc and gives access to a "pow-der puff" consisting of a primed cambric bag containing gunpowder. The powder puff is secured to a perforated disc. Its purpose is, with the aid of the perforated disc, to eject the candle unit and parachute from the flare body and to ignite the flare candle.

The candle unit comprises a steel container closed at the top by a lid and at the bot-tom by a dished washer. In the container is a magnesium alloy candle body containing a small quantity of gunpowder, some priming composition, and a quantity of incendiary composition. The hole in the washer is closed by a primed cambric disc. The candle unit is held in place in the flare body by a felt washer, felt strips, and three wooden slats. The slats extend beyond the top of the candle unit and the closing dome, and, when the flare is activated, push off the closing dome to permit the candle unit and parachute to move out of the flare body. A shackle attached to the lid connects the candle unit to the suspension rope of the parachute.

Functioning: When the fuzed flare is released from the aircraft, the fuze is set in operation, and the flare falls freely until the magazine charge explodes. The flash from the charge passes through the flash hole in the diaphragm and ignites the powder puff. The gases formed by the burning of the gunpowder in the puff exert pressure on the un-der side of the perforated disc, forcing the candle unit toward the closing dome so that the wooden slats push off the dome. The candle unit and parachute are ejected from the flare body.

The flash from the puff passes through the holes in the perforated disc to ignite the primed cambric disc and the gunpowder at the nose of the candle. The gunpowder igni-tes the priming composiiton, which in turn ignites the incendiary composition. As the in-cendiary composition burns, the magnesium alloy candle body also burns, and pieces of the burning candle fall away, giving the appearance of a vertical chain of white lights in the sky.

Suspension: A suspension band with two removable suspension lugs is secured to the flare body. The lugs are secured to the suspension band by screws having a locking wire passing through their heads. A crutch pad is also secured to the flare body.

Remarks: These flares are similar in external appearance to the 4.5 in Reconnaissan-ce Flare Mk IV.

The Flare Mk III is similar to the Mk I, except that, just below its lid, the candle unit is provided with a container filled with gunpowder. This gunpowder is ignited by the incen-diary composition and ejects any magnesium alloy which remains in the candle unit when the incendiary composition is expended. This insures that odd pieces of burning magne-sium alloy do not continue to fall after the flare has served its purpose. The Flare Mk III is identical to the Mk II except that the burning time has been increased to 120 sec. by use of a different type of incendiary composition, and of a steel container and magne-sium alloy candle body which are 3 in. longer than those in the Flare Mk II. The increased length of the candle unit is accommodated by reducing the space occupied by the para-chute.

Figure 86 – 4.5-in. Skymarker Flare No. 1 Mk I