3-in. Aircraft Rocket Flare (Service)

Over-all length

Diameter

Total weight

Candle power

Burning time

Time to primary ejection

Time to light up

Range to light up

4,800 yard when fired from ground; 5,600 yd. when fired from aircraft at 140 knots

General: This head is designed for use with 3-in. A/C Rocket Motors described in Part 3, chap. 2, H.E. Rockets, and may be fired either from aircraft or from ground launchers.

Description: The 3-in. A/C Flare Head Mk I consists of an outer body assembly and an inner canister. The inner canister is brought to an ogive at its forward end to serve as a ballistic cap. A parachute, enclosed in a cardboard housing, is contained in the upper portion of the inner canister. The long cylindrical portion of the canister is then brought down inside the main body assembly, and tabs on the bottom edge of the canister are then bent over a metal lid, retaining the lid in position. The lid consists of a metal disc, perforated in the center to accommodate the ends of two lengths of safety fuse. A baff-le plate is located between the lid and the flare candle. Lengths of quickmatch extend from the base of the candle through, the center of the baffle plate and into a gunpowder charge located between the baffle plate and the metal lid. This charge constitutes the secondary ejection charge. The safety fuse leading to it is the secondary delay.

A rocket is fixed to the lower part of the body assembly, and to the socket is welded a spigot. The spigot is threaded externally to screw into the shell ring of the rocket mo-tor, and is internally threaded to receive the Ejectior, Contents, No. 7 Mk I. The con-tents ejector consists of a threaded body, housing a diaphragm-operated striker, a per-cussion cap, and a double length of safety fuse, which extends into a gunpowder charge.

A base fairing is loosely assembled over the lower portion of the body assembly. The after end of the fairing is notched to form several tabs, and a metal clip is placed around these tabs and tigthened to ensure a firm attachment to the rocket motor. The fairing serves merely to cover the joint between the flare head and  the rocket motor, enhanc-ing the streamlining of the complete round.

Operation: The pressure of the propellant gases from the rocket motor reverses the diaphragm of the contents ejector, thus firing the cap and the safety fuse in the ejector. After the expiration of this primary delay (16 seconds) the primary gunpowder ejector charge is fired, expelling the inner container from the flare boyd assembly. The explosion of the primary charge also ignites the secondary delay.

When the secondary delay expires, the secondary ejection charge is initiated, which igntes the lengths of quickmatch beneath the flare candle, and bowls the lid out of the after end of the inner container, bending back the tabs on the base of the container.

The flare candle and the parachute assembly are now free to fall out of the after end of the container. The flare has been ignited by the flash from the lengths of quickmatch, and is suspended in mid-air by the open parachute. The purpose of the primary delay and ejection charge is to allow the flare ample time to lose velocity sufficiently so that an undue strain will not be placed on the parachute.

The flare head is painted black over-all with a ½-in. red band painted around the flare body near the base.

Remarks: This flare head may be employed with the following motors: Motor, Rocket, A/C, 3-in. (Rocket Flare) Mk I; Motor, Rocket, A/C, 3-in., No. 1 Mk I; or Motor Rocket, A/C, 3-in. No. 1 Mks II - IV.